Affordable and Sustainable Cooling Sportswear for Cycling Athletes: A Design Case Study

Abstract

Cooling sportswear products have been used to improve the comfort of individuals exposed to hot–humid climate conditions; however, these products were not explored adequately in the outdoor sports context. Moreover, it is not known if these products meet the needs of athletes in developing and tropical countries. Therefore, this study presents the design and exploratory evaluation of affordable cooling sportswear (T-shirt). Eight Sri Lankan athletes tested the sportswear prototype over three-weeks, undergoing a 30 min cycling trial that covered 15 km. The results show that the cooling sportswear improved cooling comfort, sweat evaporation, and overall comfort of the athletes by increasing ventilation and reducing body temperature. The developed prototype assisted in identifying suggestions for designing cooling sportswear products, including aesthetic, cost, functional, and sustainability considerations. These suggestions may guide researchers to develop affordable and sustainable cooling sportswear for endurance cycling athletes living in developing and tropical countries.

1. Introduction

Heat illness occurs due to excess body heat storage. The main reason for heat illness is a lack of cooling comfort or an inability to dissipate excess body heat efficiently [1]. A lack of sufficient cooling comfort may cause heat illness, and it can be worse for endurance athletes [2,3]. It has been reported that athletes experienced heat exhaustion during the World Athletics Championships marathon held in Doha, Qatar, in 2019 [4]. Therefore, endurance athletes, who conduct frequent high-intensity outdoor sports activities under high-temperature climate conditions (as in a tropical climate), have a higher heat illness risk [3]. Moreover, due to a lack of affordable cooling sportswear that can reduce the risk of heat illnesses, individuals living in low-resource countries are at high-heat illness risk [5,6,7,8]. In this aspect, endurance athletes living in tropical and developing countries require special attention. Therefore, it is vital to have an affordable cooling solution that is designed considering the requirements of endurance athletes living in developing and tropical countries to minimise the risk of heat illness.

There is minimal literature considering the needs of endurance athletes living in developing tropical countries. Researchers have introduced smart cooling concepts that can improve the cooling comfort of individuals [9], yet regardless of the potential benefits offered by existing smart wearable technologies, to the best of our knowledge, most of these existing smart wearable studies were conducted focusing on mid/high-resource countries [10] and/or for non-athletes [11,12]. Moreover, the existing smart cooling validation studies were conducted mostly in indoor controlled conditions [13,14,15,16]. Moreover, the higher price of the existing smart wearables [17] that can be used for sports/fitness activities and/or smart cooling technologies [18] informs the necessity of designing cost-effective smart cooling concepts for athletes living in developing countries. However, no cooling concept exists that was designed to focus on these athletes, and no study has been conducted to understand the cooling requirements of these athletes. Additionally, the performance and cost-specific limitations of existing cooling solutions limit those concepts only to developed and/or non-tropical regions.

Role of Cooling Comfort in Existing Sportswear

With the evolution of healthier lifestyle trends, more and more people have started engaging in sports activities, expanding the sportswear market. In 2018, the sportswear market was valued at USD 239.78 billion and a predicted compound annual growth rate (CAGR) of 10.4% from 2019 to 2025 [19]. This growing sportswear market comprises companies such as Nike, Inc., (Beaverton, OR, USA); Adidas AG, (Herzogenaurach, Germany); Li-Ning Company Ltd., (Beijing, China); Umbro Ltd., (Manchester, UK); Puma SE, Inc., (Herzogenaurach, Germany); Fila, Inc., (Seoul, South Korea); Lululemon Athletica Inc., (Vancouver, BC, Canada); Under Armour, (Baltimore, MD, USA); Columbia Sportswear Company, (Portland, OR, USA); and Anta Sports Products Ltd. Inc., (Xiamen, China) [19]. These brands offer sportswear options for a wide variety of sports categories. Due to the special nature of certain sports categories, some brands offer specialised sportswear products targeting specific sports categories. For example, POC, Pedla, Café du Cycliste, Rapha, Attaquer, Kirschner Brasil, and ASSOS are key sportswear brands that focus primarily on cycling wear [20].

Softness, dry-fit, and aesthetics are key attributes considered for sportswear apparel [21]. Some other features are lightweight, sweat-wicking technology, engineered perforations, UV protection [22], fabric coatings [23], reflective colours to enhance visibility, strategic fit to provide support, compression during sports activities, and warmth in colder climates. Using sustainable materials to promote ethical fashion is also a feature for some of these apparel; for example, a back zip pocket to carry essentials while running [24,25,26,27,28,29,30,31]. Cycling wear highlights from key brands are body fit construction, special fabric constructions that minimise aerodynamic drag, comfortable shorts pads, bib straps, silicone grippers to ensure that bib straps stay in place, and visibility-enhancing features [32,33,34,35,36].

Cooling comfort is a product feature offered by most sportswear brands [21,37] to improve the cooling comfort of the wearer, ultimately reducing heat impact of heat on health. Therefore, researchers have been working on improving the cooling comfort of sportswear, especially by manipulating fabric combinations [38]. Several suggestions were utilised to improve sportswear cooling comfort; for instance, fabrics should have air permeability and mechanisms for moisture management [39]. In addition, suitable materials may enhance the sensorial comfort properties of sportswear [40]. Sportswear brands provide various cooling technologies to build cooling comfort into sportswear. Nike introduced sweat-absorbing/evaporating dry-fit materials to enhance sweat evaporation and evaporative heat dissipation [21]. These dry-fit materials are ultra-soft, lightweight, stretchable, and have special open-knit construction to promote cooling [30]. Mauro Ribeiro uses similar technology with mesh panels offering evaporative cooling/heat dissipation [37]. The Climachill technology, introduced by Adidas, utilises conduction cooling with the help of mineral particles (aluminium cooling spheres). Additionally, the material used in this apparel concept is manufactured with SubZero yarn created from woven titanium fibres. This yarn enables maximum contact area between fabric and body to enhance heat dissipation and thus promote cooling. Climachill material is also constructed to feel lightweight and airy to boost breathability and evaporative heat dissipation [41]. Another concept from Adidas has engineered sportswear with body mapping construction, which uses three Adidas technologies: Climacool (enhance breathability), Climawarm (provide warmth in a cold climate), and Climaproof (to block wind, rain and snow without compromising breathability). The body-mapping construction allowing the placement of specific technologies makes the sportswear suitable for a wide variety of climate conditions [41]. Iso-Chill is a sportswear cooling technology offered by Under Armour, featuring a special fabric construction that helps to dissipate heat from the body, creating a cooling effect [42,43]. CoolSwitch is another cooling technology offered by Under Armour, which uses a fabric with an exclusive coating to promote cooling [44]. HeatGear is a cooling technology introduced by Under Armour, which consists of a breathable fabric that wicks away sweat and regulates body temperature [43].

Given the above, even though a wide variety of sportswear cooling concepts exist in the international market, the majority rely on natural evaporation by modifying the wicking (moving moisture away from the body) and/or breathability (allowing air to pass through the material) properties of fabrics [37,45,46,47]. The effectiveness of natural ventilation-based cooling and sweat evaporation is affected by high-humidity and hot-climate conditions [18,48]. Moreover, the majority of existing sportswear technologies are material/fabric-based; however, as claimed by some researchers, the textile properties alone cannot enhance cooling/heat comfort [49]. Consequently, cooling concepts that rely solely on natural evaporation and/or fabric-based cooling technologies may not function effectively in humid, tropical climate conditions.

Several non-fabric cooling concepts, such as cooling packs, nanoPE, and wearable cooling technologies, also exist. Cooling packs include ice or phase-changing materials (PCMs) to enhance cooling comfort for athletes and industrial and military personnel [18,50]. However, cooling packs cannot give continuous cooling because they require intermittent cooling replenishment. Therefore, cooling packs are unsuitable for long-duration sports activities [18,51].

NanoPE is a cost-effective cooling technology that uses radiation to dissipate heat and cool the wearer’s body [52]. Smart, wearable cooling with liquid/air distribution units is another cooling concept that can offer forced cooling during industrial applications conducted in hot, humid climatic conditions [14]. Some manufacturers have used such smart wearable cooling units to improve the cooling comfort of outdoor athletes [18,53]. However, prior studies have not explored the suitability and performance of nanoPE and smart wearable cooling technologies for outdoor endurance athletes. Moreover, the wearable circulatory cooling units are priced from USD 300 (roughly LKR 55,000) to USD 8000 (roughly LKR 1.5 Mn) (2016–2021) [18,54]. The comparatively high price of these concepts limits their applications to developed countries, thus overlooking individuals in developing countries [55].

Given the above, the performance and cost-related constraints of the majority of existing cooling solutions restrict those concepts to non-tropical and developed countries or to sports events that are not long in duration. Moreover, regardless of the wide variety of cooling concepts explored by researchers [56,57], the author is unaware of any study that investigates the appropriateness of existing cooling concepts for athletes living in low-resource tropical countries.

The inclusive design was introduced by researchers to include the requirements of overlooked, underprivileged consumers [58,59]. Nevertheless, the majority of inclusive design studies focus on individuals with physical disabilities, ignoring the economic and climate-specific requirements of individuals [58,60]. Researchers proposed a user-centric design approach to explore the needs of overlooked consumers [60], and some of these user-centric studies explored clothing design requirements [61,62,63,64,65]. Several user-centric clothing studies were conducted focusing on Asian and developing communities and emphasising cultural influence on clothing design [66,67]. Moreover, some user studies explored cross-cultural clothing design considerations [68,69]. However, Rahman and Jiang [68] argue that the cultural influence on clothing design may vary across diverse consumer markets and clothing categories; hence, more research is needed in this domain. Therefore, further research is needed to explore culturally related clothing design attributes, particularly in Asian and low-income countries, where the cultural impact on clothing is high.

Moreover, focusing on consumer perception of values enables the design of products that can deliver value for money, particularly for low-income individuals [70]. Even though the consumer perceived value [70,71] and cost-effective product for low-income individuals [72] were disciplines discussed in the literature widely, the existing studies have not adequately explored how these strategies improve the affordability of high-performing sportswear for athletes in developing countries.

Moreover, further investigation is needed to explore cultural, sustainable, and cost-related aspects of sportswear design, particularly in the context of developing countries. While sportswear cooling is a widely explored domain for athletes in developed countries, it is essential to design a cooling concept that provides cooling comfort without compromising affordability. Given all of the above, it is of great interest to design a custom-made, affordable cooling sportswear for athletes living in a developing and tropical country to minimise the risk of heat illness and improve cooling comfort during outdoor sports activities. This study reports the design and exploratory evaluation of such affordable, co-designed, and custom-made cooling sportswear with endurance cycling athletes living in a developing and tropical country, Sri Lanka.

2. Our Cooling Sportswear Prototype: Design Process and Considerations

The design process of our sportswear prototype was guided by the apparel design framework proposed by Lamb and Kallal [73], which employs a functional, expressive, and aesthetic (FEA) apparel design model. This design approach consists of six phases: problem identification, preliminary ideas, design refinement, prototype development, evaluation, and implementation. Furthermore, this process suggests using the functional, expressive, and aesthetic (FEA) design model for the problem identification and evaluation phases of the design process. We also reviewed the apparel design process by Watkins [74] and the apparel design case study by Bye and Hakala [75]. Our design process was also inspired by user-centred design and RtD (Research Through Design) approach and consisted of iterative user studies and prototyping activities. The design process was also inspired by user-centred design and RtD (Research Through Design) approach and consisted of iterative user studies and prototyping activities. The design process had several stages, such as a focus group study (n = 20 participants), co-design workshops (n = 20 participants), prototype development, and field testing (n = 8 participants) with Sri Lankan athletes. The key findings of the focus group study were reported elsewhere [76,77].

We conducted four co-design workshops to explore Sri Lankan endurance cycling athletes’ cooling requirements and brainstorm design features to address these requirements. Co-design is a means of understanding innovation opportunities and facilitating new product development [78,79]. Co-design enables researchers to understand complicated health-related conditions/concerns of people and to recognise the role that technology can play in managing those conditions [80]. According to Sanders and Stappers, co-design can create new “domains of collective creativity” [81].

During the design workshops, the participants stated that existing sportswear was not providing enough cooling comfort to them and expected cooling sportswear that could function effectively in tropical climate conditions. They also suggested exploring possibilities of designing cooling sportswear that can offer personalised cooling comfort. The participants reported the upper back as their most sensitive body zone and the chest, upper back, and underarms as sweat-accumulating zones. Participants proposed a cooling sportswear design that consisted of cooling technology in the upper back area. The proposed design should be cost-effective and use lightweight perforated panels in the chest and underarms to promote sweat evaporation and evaporative cooling.

2.1. Considerations for Developing an Affordable Cooling Unit

We reviewed several cooling technologies, such as basic cooling (i.e., yarn and fabric technologies, breathable structures, perforation cooling packs) and smart cooling (i.e., liquid cooling, air cooling, and Peltier/thermoelectric cooling) to find a suitable cooling technology that would fulfil the needs of the athletes while keeping the cost minimum. Existing wearable fan cooling studies [15,82] showed the integration of fan cooling into the garment, either with two or more fans or with both fans and phase-changing materials (PCM). PCM packs increase the weight and bulkiness of the garment, which can cause adverse effects on sports performance. Hence, we used a unique design based on the suggestions provided by the participants to gain maximum advantage from the freely available wind cooling effect. We used lightweight perforated materials in the body sweating zones to enhance sweat evaporation and natural wind cooling. Informed of user preferences during the co-design workshop and also considering the cost-effective, portable, and lightweight nature of air (fan) cooling technologies [83], we used fan air cooling as the cooling technology in the sportswear to offer cooling comfort to athletes. We used a fan (axial fan used in computers) in the most heat-sensitive body zone (upper-back/back-neck) to provide forced-air cooling. Axial fans generate airflow in the axial or perpendicular direction and can usually generate a high airflow volume.

An air-cooling fan was selected as the cooling technology for our sportswear prototype after considering user preferences and the low-cost and light weight nature of the technology compared to other smart cooling technologies [83]. Air-cooling concepts are also known as ambient air systems that allow air to circulate through a garment. Moreover, the hybrid design consisting of smart cooling and perforated materials of the proposed sportswear design provides cooling comfort to a wider body area of an athlete with minimum technology intervention. Hence, a cost advantage can be obtained. Moreover, the circuit components of the prototype were made water repellent, heat resistant, and reinforced to improve durability, thus improving sportswear’s lifetime and ultimately reducing user cost expenditure. Considering the design suggestions (See

Table 1. Cooling sportswear design rationale based on participants’ feedback.

Feature	Rationale
Cooling in the upper back	The participants suggested the upper back area of the body as the most heat-sensitive body zone.
T-shirt designed with a perforated material	Participants suggested using perforated materials and fan cooling to improve sweat evaporation and evaporative cooling.
Axial fan	To generate a high airflow volume
The cooling control switch (ON/OFF/Cooling levels)	Participants preferred having personalised cooling control. Participants suggested having different cooling levels
Detachable cooling unit	The participants preferred detachable cooling units to ensure the cooling sportswear could be washed.
Wires encapsulated in water repellent tube	Participants suggested making circuit units water repellent to improve durability and safety when conducting activities in outdoor conditions
High-capacity rechargeable battery	Participants suggested using a high-capacity rechargeable battery to improve the cooling duration and reduce battery replacement cost
Sustainability considerations	Reuse sportswear, circuit units in the sportswear, and utilise natural power

), we iteratively developed the cooling sportswear prototype as explained in the below section.

2.2. Description of the Sportswear (T-Shirt) Prototype

We manually modified an off-the-shelf sportswear T-shirt made from a perforated material (to support sweat evaporation and wind cooling) to design the prototype, as the T-shirt has moisture transport properties to provide improved cooling comfort [84]. We attached a 5 V axial cooling fan to the upper back area of the T-shirt. The fan (77 mm × 56 mm [85]) is powered by a high capacity, rechargeable 1200 mAh, 5 V battery connected to a push-button switch, which also acts as the speed controller. A LED is located near the switch. The speed controller push button enables three fan speed levels: low, mid, and high. The LED emits a blue indication when the fan is operating. The battery, circuit board, and switch controller were encapsulated inside a waterproof casing. A pocket was designed just below the shoulder to hold the switch controller unit. This pocket has Velcro tape to retain the cooling controller unit (switch, battery, and circuit board encapsulated in plastic casing). The fan was placed in a pocket construction attached to the upper back area of the T-shirt, which was made from a mesh material to allow the air circulation required for the fan operation. The wire connection attached to the switch/speed controller was placed inside a tube made from water-resistant fabric. Circuit wires were located in a waterproof fabric tube to improve their durability and safety. The entire cooling unit, including this tube, is detachable and waterproof to allow home laundering (Refer to Figure 1 and Figure 2; and

Table 2. Key features of the cooling sportswear prototype.

Feature	Details
Weight	271 g
Cooling zones	Back neck/upper back; full upper body
Cooling control	Using an ON/OFF switch
Cooling technology	Lithium battery-operated cooling fan Perforation allowing wind cooling
Technology integration	Fan unit: mesh pocket placed in the upper back zone Switch: pocket placed just below the shoulder
Other features	LED: visualise when the fan cooling is in active mode
Rough cost	AUD 20

). The total weight of the prototype is 271 g, and it costs 20 Australian dollars (AUD 20). Eight prototype samples were made considering the rough body measurements of the field study participants.

3. Field Evaluation of the Cooling Sportswear

This study was conducted while the COVID-19 pandemic was prevailing in Sri Lanka, so the study was conducted remotely without the in-person involvement of the research team (due to social distancing and travel restrictions). Considering this and considering the practical limitations associated with measuring the physiological parameters of the athletes without the involvement of the research team (e.g., precise sensor placement for temperature monitoring), the study was designed to rely entirely on self-reported perceptual feedback of the participants. This study was designed to address the key research questions as follows:

• How do participants perceive the cooling sportswear prototype?
• What are the recommendations of the participants to design cooling sportswear that would suit athletes who are living in a developing and tropical country?

3.1. Participants

Eight Sri Lankan athletes volunteered to participate in this study. They were (a) aged 27.5 ± 7.5 years, (b) must have participated in 70 km or lengthier cycling event/s (and frequently conducting cycling activities), (c) must be healthy, and (d) must not have been in close contact of a COVID-19 positive case. The participant recruitment was conducted through online advertisements published on a Sri Lankan website (www.ikman.lk, accessed on 2 February 2023). Regarding health, we only recruited participants who do not have a pre-existing physical injury, have not been exposed to a hazardous environment, have not undergone surgery, and were not suffering from or suffered from any kind of health conditions (venous insufficiency, cardiovascular, pulmonary, or metabolic diseases, and/or peripheral vascular disease). The eight participants consisted of four Sri Lankan endurance cycling athletes who had participated in our previous design workshops and four newly recruited participants. We labelled the repeated four participants as B1, B2, B3, and B4, and four newly recruited Sri Lankan endurance cycling athletes were labelled as A1, A2, A3, and A4. This was performed to identify if the newly recruited participants had different feedback on the prototype.

3.2. Procedure

All participants underwent a 30 min cycling trial while wearing the prototype and a smartwatch over a three-weeks period (a total of six trials). Each 30 min cycling trial covered 15 km. The participants were instructed to conduct these cycling trials under two conditions.

Cooling sportswear prototype (SP): 2nd to 5th trials were conducted while wearing the custom-made smart sportswear prototype. The fan was kept switched on (full speed) during the entire trial duration.

Controlled prototype (CON): 1st and 6th trials were conducted wearing the same cooling sportswear prototype but without the fan unit activated.

The participants were instructed to use the prototype during the day when conditions were hot (average temperature 27–33 °C, 60–80 humidity) and to handwash the prototype after two consecutive uses. The participants were instructed to wear the same cycling shirts for all of the trials. All cycling trials were conducted in cycling tracks located in Colombo and surrounding suburbs (with similar climate conditions), Sri Lanka.

During the field trial period, the participants engaged in a diary study to record their experiences with the sportswear prototype, including the environmental temperature recorded from their mobile phones before and after the trial. The athletes were instructed to update the diary after completing each trial. Participants could record details such as trial date, trial time, likes, dislikes, improvement suggestions for the prototype, technical concerns, and other comments related to the trial. This diary also contained rating scales to collect participant feedback. The diary was designed in the Sinhala language (the native language of the participants), and participants were provided with the flexibility to update the diaries at their homes.

After completing all the cycling trials and the diary study, we conducted a focus group with the participants to discuss the field study experience and the diary study feedback. The key areas covered during focus group discussions were participants’ feedback regarding the features/factors they like about the sportswear prototype, features/factors they do not like about the smart prototype, and improvement suggestions.

The focus group consisted of two sessions, and each session had four participants. The first session was for group A (fresh participants), and the second session was for group B participants. Each focus group session (30 min). The group discussions were conducted online (WhatsApp) in the Sinhala language and were audio-recorded for further analysis.

3.3. Data Collection

We collected audio recordings of the focus group discussions and the diaries for analysis. The collected materials consisted of qualitative data such as diary logs and audio recordings of focus group discussions. The quantitative data collected were the rating scale (See

Table 3. Rating scales: thermal comfort, wetness sensation, easy care, and overall comfort.

Rating Scale	Cooling Comfort	Wetness Sensation	Easy Care	Overall Comfort
3	Very Warm/Hot	Very Wet	Very difficult	Very Uncomfortable
2	Warm	Wet	Difficult	Uncomfortable
1	Slightly Warm	Slightly Wet	Slightly Difficult	Slightly Uncomfortable
0	Neutral	Neutral	Not Difficult	Comfortable
−1	Slightly Cool	-	-	-
−2	Cool	-	-	-
−3	Very Cold	-	-	-

-: Not applicable.

) responses provided by the participants for thermal/cooling comfort [86,87], wetness sensation [88,89], overall comfort with the prototype, easy-care properties of the prototype, and usability of the prototype. The usability was measured based on the ease of use, usefulness, and satisfaction with the sportswear. The usability metric consisted of a 7-point scale (1 = strongly disagree to 7 = strongly agree) to collect user feedback [90].

3.4. Data Analysis

We transcribed and/or translated the collected data. The translations were verified by another native Sinhalese fluent in English (an international graduate). We assigned pseudonyms to the participants (A1-A4, B1-B4) to ensure confidentiality. We thematically analysed the qualitative data extracted from the translated transcripts and the diary logs using NVivo 12 software [91]. The main themes were guided by the quantitative metrics used to collect user perception, explained in the previous section. The main themes derived from qualitative data are (1) cooling comfort and sweat evaporation; (2) overall comfort; (3) easy care, handling, and wearability; (4) cooling control; (5) usability; and (6) design considerations. The first and second authors reviewed the themes independently, and any disagreements were resolved after a discussion. The quantitative data collected was analysed using relevant descriptive and inferential statistics. An unpaired t-test was used to analyse the user feedback from the new and repeated participants. We also provided the relevant values for means (M) and standard deviations (SD).

4. Results

4.1. Cooling Comfort and Sweat Evaporation

Cooling comfort represents the reduction in heat discomfort experienced by the participants. A lower rating represents higher cooling comfort and decreased heat discomfort. The one-tail unpaired t-test shows that when conducting the cycling trials with the SP (M = −0.6 (slightly cool), SD = 0.5) compared to the cycling trials conducted with the CON (M = 2.19 (warm), SD = 0.4), the participants experienced significantly improved cooling comfort/reduced heat discomfort in the upper back area of the body, t (46) = 19, p = 1.1 × 10⁻²³. Refer to Figure 3a for the average thermal comfort/cooling comfort rating for each trail.

The wetness sensation demonstrates the efficiency of sweat evaporation from the body, which reduces body wetness. A lower wetness rating represents lower sweatiness. The participants rated the wetness sensation they experienced in the upper back area as they mostly experienced an improvement in this body zone. The one-tail unpaired t-test shows that when conducting the cycling trials with the SP (M = 1.34 (slightly wet), SD = 0.48) compared to the cycling trials conducted with the CON (M = 2.6 (very wet), SD = 0.51), the participants experienced significantly improved sweat evaporation/reduced wetness sensation in the upper back area of the body, t (46) = 8.08, p = 1.12 × 10⁻¹⁰. Refer to Figure 3b for the average wetness sensation rating for each trail.

According to the study participants, the air temperature minimises the cooling performance of the sportswear prototype when conducting cycling for a longer duration. The participants suggested using an added mechanism that can provide cooled air to the body together with fan cooling to address this concern.

“When the air is too hot, the cooling feeling gets reduced. If it is possible to use cool air, then this concern will get minimized”

1A

One participant suggested using a compressor system attached to the bicycle to provide cooled air to the cooling sportswear with minimum weight impact.

“Use cool air to improve cooling comfort with the help of a simple unit and a compressor attached to a bicycle to minimize the impact on weight”

A3

To address this aspect, the participants suggested enhancing fan air circulation inside the cooling T-shirt with the help of a tube system.

“Improve air circulation in the upper body using fabric tubes, garment constructions that support air circulation inside the upper body”

A4

4.2. Overall Comfort

The overall comfort ratings indicate that the comfort of the participants improved due to the cooling garment. A lower overall comfort rating represents a decreased comfort level. The two-tail unpaired t-test shows that when conducting the cycling trials with the SP (M = 0.94 (slightly comfortable), SD = 0.67) compared to the cycling trials conducted with the CON (M = 1.94 (uncomfortable), SD = 0.25), the participants experienced significantly improved overall comfort/reduced overall discomfort, t (44) = 7.48, p = 2.31 × 10⁻⁹. Refer to Figure 3c for the average overall comfort rating for each trial.

Regardless of the enhanced cooling comfort, all of the participants felt strange wearing the cooling prototype consisting of the fan circuit. To address this, participants suggested exploring advanced technologies that can integrate smart technologies into fabrics/clothing and secure circuit components to minimise electric shock. One participant suggested using cooling fabrics instead of a circuit to enhance their cooling comfort.

“Try to use familiar cooling concepts like cooling fabrics and meshes, Sri Lankan athletes are not familiar with wearing unusual components”

2A

Participants suggested integrating the entire circuit into the fabric to minimise the discomfort arising due to hard components and to reduce the unfamiliar feeling they felt when wearing a circuit. Moreover, the participants suggested using soft, skin-friendly cotton-like fabric in the sportswear to improve their touch comfort.

“If possible, design all the wires inside the fabric and use a fabric switch”

2A

4.3. Easy Care and Handling

The easy-care and handling of the cooling garment were measured from the participant’s perceptions on how easy it was to handle and wash the cooling garment. The participants were not happy with the “easy care” properties of SP (M = 1.7 (difficult), SD = 0.68) (refer to Figure 4). The two-tail unpaired t-test shows that group B participants (M = 1.4 (slightly difficult), SD = 0.52) compared to the group A (fresh) participants (M = 2 (difficult), SD = 0.73) demonstrated significantly better easy-care rating for SP, t (30) = 2.52, p = 0.002.

As stated by the participants, since Sri Lanka is a tropical country, sweat accumulation in sportswear is comparably high, causing an unpleasant odour. Hence, sportswear needs to be washed regularly, and the participants liked the possibility of detaching the non-washable cooling unit to enable the washing of the cooling sportswear.

“As we are in a tropical country, we need to wash the garment frequently due to sweat and its smell”

A1

However, since the participants did not have prior experience with smart wearables, handling these detachable units was inconvenient for them; hence, they suggested exploring advanced technologies to design a washable cooling circuit so the sportswear can be washed without the need to detach the fan cooling unit. As further stated by them, such a design will increase the easy care and handling of the cooling garment.

“Have to separate the unit from washing the garment. The unit cannot be cleaned or washed”

2A

“Use advance technologies to print the circuit to the fabric”

B3

Another concern highlighted by the participants is that in the current prototype, it was difficult to wear the sportswear while the fan cooling unit was attached, and to attach the fan cooling unit after wearing the sportswear, they needed the support of another person. To address this concern and to improve the wearability of the prototype, they suggested improving the garment design by using a sportswear-embedded cooling circuit.

“We need assistance from somebody else to wear the cooling unit to the T-shirt”

A2

4.4. Cooling Control

Participants were happy with the push-button control used to control the cooling function to obtain personalised cooling comfort. However, they suggested a few modifications to improve the usability of the cooling control function further. One such suggestion is using a separate switch to control the ON/OFF function of the fan rather than using the same push-button for ON/OFF and cooling level control.

“I have seen in stand fans with different switches. Then it would be easy to control. At least put a separate on/off switch”

A2

Some participants suggested designing the switch in hand or glove to improve the accessibility for switch control. The participants also suggested using a voice command signal system to control the cooling function, so they do not need to use their hands to operate the switch/push button while riding. However, the participants emphasised that approvals need to be taken to use the microphone system during races.

“Even though it is easy to control the cooling function, we need to use our hand to control the unit. This will be dangerous and affect our performance when we ride on the road. So, it is better if a voice command signal system can be used to operate the cooling control function”

A3

4.5. Usability

The usability of the cooling sportswear was evaluated to understand the overall performance of the prototype using three perceptual parameters “usefulness”, “easy to use”, and “satisfaction”. The participants moderately agreed that the SP is “useful” (M = 5.75, SD = 0.84) and “easy to use” (M = 5.25, SD = 0.84). They were also moderately “satisfied” with SP (M = 5, SD = 0.72) (refer to Figure 5).

The two-tail unpaired t-test shows that group B participants (M = 6.25, SD = 0.86) compared to the group A (fresh) participants (M = 5.25, SD = 0.45) demonstrated significantly better “usefulness” rating for SP, t (23) = 4.14, p = 0. Moreover, the group B participants (M = 5.5, SD = 0.52) compared to the group A (fresh) participants (M = 4.5, SD = 0.52) demonstrated significantly better “satisfaction” ratings for SP, t (30) = 5.43, p = 0.

However, there was no significant difference in “easy to use” perception between group A and B participants, t (15) = 1.73, p = 0.1, despite group B participants (M = 5.5, SD = 1.55) demonstrating better “easy to use” ratings than group A participants (M = 5, SD = 0).

4.6. Considerations for Developing Affordable and Sustainable Cooling Sportswear

4.6.1. Cooling Comfort and Sweat Evaporation

The participants experienced enhanced cooling comfort in the upper-back area when wearing the refined prototype. Moreover, group B participants stated that the cooling performance of the prototype was better than the initial prototype options that they experienced in a previous study. Furthermore, the participants experienced reduced sweat accumulation in the upper back area of the body due to the fan-cooling effect.

Since both fans and perforated materials (wind cooling) function based on the evaporation of body sweat, the participants expected a higher cooling effect when cycling at a higher speed and for a longer duration, as this causes a higher sweating rate. However, the study participants stated some modifications that need to be explored to further improve overall cooling comfort and sweat evaporation, ultimately improving the overall comfort of the prototype.

4.6.2. Pre-Cooled Air

According to the study participants, the air temperature minimises the cooling performance of the prototype when cycling for longer in Sri Lanka’s hot tropical climate. To address this concern, the participants suggested using an added mechanism that could provide cooled air to the body along with fan cooling. The participants suggested using a compressor system to provide pre-cooled air to the fan cooling unit and suggested attaching the compressor to the bicycle to minimise the weight impact on the body.

“When the air is too hot, the cooling feeling gets reduced. If it is possible to use cool air, then this concern will get minimized”

1A

“Use cool air to improve cooling comfort with the help of a simple unit and a compressor attached to a bicycle to minimize the impact on weight”.

A3

4.6.3. Enhance Air Circulation

The participants liked having a fan-cooling effect in the upper back area of their bodies. Moreover, they agreed that improving cooling comfort in the upper back zone will influence overall cooling comfort. However, they stated the importance of providing a fan-cooling effect to the full upper body to further improve overall cooling comfort.

“This unit improves cooling in our upper-back area, improving overall comfort. If the cooling garment can provide this kind of cooling to the full upper body, then overall comfort will increase significantly”.

A4

One participant suggested a few other design considerations that could be used to enhance air circulation inside the T-shirt without using a complicated tube system. As stated by this participant, the forced airflow generated by the fan is not retained inside the T-shirt due to the current design, ultimately reducing the air circulation. He suggested minimising the open constructions in the T-shirt to lessen this concern. He proposed sealing the neck and armhole openings of the T-shirt with the help of a body-fit construction, minimising the hole size of the outside fan pocket panel and using the fabric in the T-shirt, which does not allow air to go out but allows moisture particles to wick away through it.

“The airflow created by the fan does not retain inside the garment because of the openings. If the garment can be made a body-fit, and the neck and sleeves openings can be made in such a way that the air will not go out from those places, then the air circulation of the fan inside the garment will become increased. The outside mesh panel of the pocket should have a small hole to minimize air going outside. Rather than using perforated material for the whole fabric in the T-shirt, use another type of fabric that can absorb and remove sweat from the body”.

1A

4.6.4. Using an Advanced Fan

Even though the author used a larger fan with better airflow in the prototype than the fan used for the initial prototype/s, the participants recommended enhancing cooling comfort further by integrating a more advanced high-speed fan. However, they emphasized the importance of using a fan that could give better cooling without increasing its size to minimise the impact on the aesthetics and overall comfort of the cooling sportswear due to the bulky fans attached to the sportswear.

“Use advanced and thin fans”.

3B

4.6.5. Odour Due to Accumulated Sweat

Regardless of the improvement in sweat evaporation, the odour caused by the trapped sweat in the sportswear was a major concern for the participants. Hence, they stated a few other proposals to minimise the smell arising from the accumulated sweat in the sportswear.

“When we are cycling, we notice a bad smell in the garment due to sweat. Is it possible to find a solution to prevent or to control this odor?”.

A3

One suggestion to address this concern was an odour-controlling fabric in the sportswear. Others suggested fragrance-emitting technology in sportswear to minimise foul body odour.

4.6.6. User-Technology Interactions

The cooling control function requires user technology interactions while riding. Participants were happy with the push-button control used to control the cooling function. However, they suggested a few modifications to improve the usability. One such suggestion was using a separate switch to control the ON/OFF function of the fan rather than the same push-button for ON/OFF and the cooling level control.

“I have seen stand fans with different switches. Then it would be easy to control. At least, if possible, put a separate on/off switch, that would be better”.

A2

Some participants suggested designing the switch to be in the hand or the glove to improve the accessibility of the switch control. The participants also suggested using a voice command signal system to control the cooling function, so they do not need to use their hands to operate the switch/push button while riding.

“Even though it is easy to control the cooling function, we need to use our hand to control the unit. This will be dangerous and affect our performance when we ride on the road. So, it is better if a voice command signal system can be used to operate the cooling control function”.

A3

Another participant suggested an unusual approach to controlling the cooling function by using advanced technology to control the cooling function by the mind.

“If possible, use advanced tech that enables controlling the cooling level by mind”.

4A

4.6.7. Powering

The participants liked the easily rechargeable battery used for the prototype. However, they suggested using solar energy to power the prototype, thereby reducing the electricity cost and gaining maximum benefit from natural resources. Powering the cooling unit from the mechanical energy generated by the cycling activity was another suggestion provided by the participants.

“We need to charge the battery before the ride. In Sri Lanka, we do ride in sunny days, so it is possible to use solar power system”.

A3

“Use cycling energy to power the battery”.

4A

4.6.8. Easy Care and Wearability

As stated by the participants, since Sri Lanka is a tropical country, sweat accumulation in sportswear is comparatively high, thus causing an unpleasant odour. Hence, sportswear needs to be washed regularly, and the participants liked the possibility of detaching the non-washable cooling unit to enable the washing of the cooling sportswear. However, they suggested exploring the options of using advanced technologies to design a washable cooling circuit so the sportswear could be washed without the need to detach the fan cooling unit. As further mentioned by them, such a design would also increase the easy care and handling of the cooling garment.

“As we are in a tropical country, we need to wash the garment frequently due to sweat and its smell”.

A1

“I heard some technologies that make fabrics with electronic circuits; if it is possible to use that sort of technologies, then it would be easier to wash and clean the cooling sportswear”.

A2

Another concern highlighted by the participants was that in the current prototype, it was difficult to wear the sportswear while the fan cooling unit was attached and that to attach the fan cooling unit after wearing the T-shirt, they needed the support of another person. To address this concern and to improve the wearability of the prototype, they suggested improving the garment design by using a sportswear-embedded cooling circuit.

“We need assistance from somebody else to attach the cooling unit to the T-shirt”.

A2

4.6.9. Durability

Participants were unhappy with the durability of the prototype and suggested some modifications to address this drawback. Making the heat of the circuit resistant to environmental heat was one such suggestion. Moreover, due to the humid climate in Sri Lanka, the participants suggested using protective chemicals in the circuit components to minimise the potential circuit malfunctioning risk.

“The circuit components can get damaged due to heat, so need additional heat protection. Also, Sri Lanka is humid; hence, the circuit can get damaged due to contact with moisture, hence use protective chemicals”.

1A

Fully waterproofing the circuit components was another suggestion to protect them from sweat, rain, and also from water-throwing activity by Sri Lankan race observers. The participants also had concerns regarding the physical damage to the hard circuit components from falling.

“The unit should be enclosed in a more reinforced pocket; otherwise, if we fall, the unit will get damaged”.

2A

Poor wash durability of the Velcro was another concern. Participants recommended replacing Velcro with a more long-lasting alternative. They also stated that the cooling unit’s detachable nature could also cause damage to the circuit, thus reducing durability. As further noted by them, frequently attaching and detaching the cooling unit from the garment can damage the circuit and the T-shirt; hence, a washable, wearable cooling circuit embedded into the T-shirt would be more durable.

4.6.10. Smart Monitoring

Even though the participants were happy with the fact that the prototype was designed to mainly focus on cooling comfort, they wanted to add a few additional smart functions to improve the smartness of the prototype. Environmental monitoring was one such idea. They suggested using biomonitoring, emphasising the importance of body temperature monitoring to obtain a visual indication of the cooling garment’s performance. They also suggested displaying the measured body/environmental parameters of the sportswear in the speedometer attached to the bicycle or in a smartwatch.

“There is no indication to see whether our body is cooled down. It is better if the body temperature can be measured and displayed in a watch or a screen”.

A3

However, regardless of the participants’ preference to have a smart monitoring function, they emphasised that cost needed to be considered when adding these additional functions to smart sportswear.

4.6.11. Versatility

The participants proposed a few aspects to enhance the versatility of the cooling garment so they could maximise its benefits. One such suggestion was to improve the cooling garment design to use it for cycling races, outdoor exercises, and outdoor travelling. This modification would allow them to use the cooling garment for a broader range of activities. As further stated by the participants, to fulfil this requirement, the cooling garment should be designed with better aesthetics. They suggested a cooling circuit embedded in the fabric to fulfil this purpose.

“Make the cooling garment in such a way so we can wear it even when we go out to do exercising or when walking under sunlight. With current unusual aesthetics, we feel uncomfortable wearing a garment like that. If a fabric integrated circuit can be used in the T-shirt, then we can use the garment for cycling and also for other activities increasing the value of what we paid”.

2A

One participant suggested improving the cooling function of the prototype so they could use it not only to enhance cooling comfort but also for body recovery after endurance sports activities. Ensuring that the cooling sportswear could even be worn as a normal T-shirt (when cooling is not needed) was another suggestion.

4.6.12. Hydration

Some participants emphasised the importance of maintaining the water-throwing activity even with the cooling garment to ensure that they were hydrated enough when riding in hot climate conditions. However, with the current prototype, they could not conduct this activity since the circuits are not fully waterproof. As suggested by the participants, waterproofing circuits can address this concern. The participants also proposed integrating water spray into the cooling fan to create hydrated airflow while riding in hot climate conditions.

“Use water spray with a fan”.

2A

4.6.13. Safety

The participants were not familiar with smart garments and/or wearable technologies; hence, they had concerns regarding possible electrical discharges that might arise from the cooling prototype. As further stated by them, such electric shocks could cause serious accidents while riding. The participants commented that protecting the circuit from heat, water, and physical damage would reduce this concern while increasing their confidence to wear the smart garment.

“Improve safety by securing the circuit for water, heat and physical damages. Otherwise, we will end up getting an electric shock from the damaged circuits while riding”.

A4

One participant suggested integrating a sensing technology into the sportswear to alert the wearer when there is a risk of electric shock in order to minimise feelings of insecurity. Another concern mentioned by the participants was having to wear a battery near the chest area under direct sunlight. The batteries might become overheated while riding, causing hazards to the body. To minimise this concern, they suggested using a heat-reflective or cooling panel to cover the battery casing. Some participants also suggested moving the battery to another location rather than the chest area to minimise the health impact.

“Battery is located in the chest area without heat removal technology. Use heat-reflecting or cooling panel near the battery to improve safety”.

1B

Moreover, the participants stated the importance of integrating additional features such as UV protection into the sportswear to protect them from unhealthy UV sunlight while riding and to use high visibility LED to minimise road accidents.

4.6.14. Other Comfort-Related Considerations

Regardless of the enhanced cooling comfort, some participants (mostly group A) felt strange wearing the cooling prototype with the fan circuit and suggested using cooling fabrics instead of a circuit to enhance their cooling comfort. This unfamiliar feeling reduced their overall comfort.

“Try to use familiar cooling concepts like cooling fabrics and meshes, Sri Lankan athletes are not familiar with wearing unusual components”.

2A

Some participants suggested providing awareness about cooling garments to Sri Lankan athletes to minimise the unfamiliar feeling. They also stated that wearing a hard cooling unit while riding reduced their touch comfort. A few suggested using a soft, flexible switch to minimise this concern. Guided by the technology demonstration conducted by the author, some advocated integrating the entire circuit into the fabric to minimise the discomfort arising from hard components and to reduce the unfamiliar feeling they felt when wearing a circuit. Moreover, the participants suggested using a soft, skin-friendly, cotton-like fabric to improve their touch comfort.

“If possible, design all the wires inside the fabric and use a fabric switch”.

2A

The noise of the fan was also identified as a concern that affected their overall comfort, and they suggested addressing this issue.

4.6.15. Aesthetics Considerations for Cooling Sportswear

The participants were not happy with the unusual aesthetics of the sportswear and suggested using attractive colours and better garment designs to address this concern.

“Appearance of the garment is not good and needs to be improved. Use attractive colours, design. It should be attractive enough to buy and use”.

B1

Some participants suggested using a thin fan to minimise the distortion in the sportswear that occurs due to the fan.

“Fan is bulky and distorts appearance”.

3B

Increasing the visibility of LED was another suggestion stated by the participants to improve the aesthetics of the sportswear. They proposed using LED technology to visualise their names or logos in the sportswear. According to them, this design feature would also improve rider visibility and minimise road accidents.

“Use LED lights to indicate my name, number or logo, and to improve the visibility of the T-shirt. Then it looks techy”.

3A

The participants were concerned with the transparency level of the sportswear fabric. They preferred having a less transparent yet, sweat-removing fabric in the sportswear.

“Use sweat removing fabric that is not transparent like this one”.

1B

4.6.16. Cost-Related Considerations for Cooling Sportswear

The participants emphasised that the affordability of the cooling garments was an important consideration.

“For a country like Sri Lanka, affordability is a concern, so I think that the cooling sportswear should be affordable for most Sri Lankans”.

B2

Due to the simplicity of the prototype, the participants believed that the cooling garment was affordable to them. However, they stated a few aspects that needed to be considered when designing a cooling garment to further enhance affordability and value for money.

The participants identified the durability of the sportswear as an essential consideration to ensure value for money. As further elaborated by them, Sri Lanka is a tropical country; hence, it does not have seasonal apparel/fashion trends. Therefore, individuals/athletes living in Sri Lanka prefer durable clothing that can be worn for a longer duration rather than replacing clothing frequently based on seasonal fashion trends.

“We are not having seasons like western countries so do not have seasonal fashion trends. Hence, if the product can be made durable, it will increase the value for money and also reduce the impact on the environment”.

1B

Improving the versatility of the cooling garment to ensure maximum value and use and exploiting local resources and technologies to obtain cost advantage were a few other suggestions stated by the participants.

4.6.17. Sustainability-Related Considerations for Cooling Sportswear

As stated by the participants, Sri Lankan culture is closely linked with the environment; hence, they liked using clothing that had minimum impact on the environment. They were inspired by the PET bottle recycling initiative practised in Sri Lanka and suggested using recycled fabrics, bio-degradable circuits, and natural energy sources to minimise the environmental impact.

“Make the garment from recycled fabrics, I have seen there are some garments made out of plastic bottles”.

2A

“Try to use technologies that can minimize the landfill issue that occurs due to non-biodegradable circuits; also, try to use sustainable solar energy”.

1B

Figure 5 shows all the design considerations discussed above.

4.7. Prioritising User Suggestions and Proposed Cooling Garment

From the suggestions provided for the prototype (See Figure 6), the field study participants listed the most important design considerations that needed special attention (refer to

Table 4. Functional considerations for developing cooling sportswear products.

Attributes	Design Considerations	Group A	Group B
Cooling	Use pre-cooled air.	X	X
	Use a compressor attached to the bicycle.	X	NOT
	Enhance air circulation by using a tube system.	X	X
	Enhance air circulation by improving garment design to retain more air inside the garment.	X	X
	Use advanced fans/high-speed fans.	X	X
Powering	Use natural resources such as solar and mechanical energy generated from cycling to power the cooling unit.	X	X
User-technology interactions	Use a separate switch to trigger ON/OFF.	X	NOT
	Voice command signal to control cooling function.	X	X
	Switch placed in the hand or glove.	NOT	X
	Advanced technology that allows cooling control by the mind.	X	NOT
Durability	Protect from heat, water, and physical damage.	X	X
	Wash durability—Velcro.	X	X
	Washable, wearable cooling circuit embedded into the T-shirt to reduce frequent attaching and detaching of the unit.	X	NOT
Versatility	Use of cooling garments for a wider range of activities (races, exercise, outdoor travelling) to improve cooling comfort.	X	NOT
	Use of cooling garment for post-activity recovery.	NOT	X
Hydration	Integrate water spray into the fan.	X	NOT
	Make circuits water repellent to enable water-spraying while riding.	X	X
Other smart functions	Biomonitoring.	X	X
Odour Control due to accumulated sweat	Use the odour control mechanism in the sportswear.	X	X
	Use fragrance emitting effect.	X	X
Easy Care and Wearability	Use advanced technologies to design a washable and wearable cooling circuit.	X	X
Softness and other related comfort	Use soft, skin-friendly cotton-like fabric.	NOT	X
	Use soft, flexible components in the circuit.	X	X
	Embed circuit inside the fabric.	X	NOT
	Reduce fan noise.	X	NOT
	Use cooling fabrics to enhance cooling instead of the fan circuit.	X	NOT
Lightweight	Attaché cooler/compressor bicycle.	NOT	X
Rider Safety	Protect the circuit from water, heat, and physical damage.	X	X
	UV protection.	NOT	X
	Increase rider visibility by LED.	X	X
	Minimise hazardous heat from the battery. Use a heat reflecting/cooling panel to cover the battery casing.	X	X
	Place the battery in a safer location than the chest.	X	NOT

X: Suggested by the participants. NOT: Not suggested by the participants.

and

Table 5. Non-functional considerations for developing cooling sportswear products.

Attributes	Design Considerations	Group A	Group B
Cost	Improve durability	X	X
	Improve versatility.	X	X
	Use local resources and technologies	X	X
Sustainability	Use recycled fabrics	X	NOT
	Use bio-degradable circuits	NOT	X
	Use natural power sources	X	X
Aesthetics	Increase LED visibility	X	X
	Use LED technology to visualise names or logos in the sportswear	X	X
	Reduce the transparency level of the sportswear	NOT	X
	Use attractive colours and garment design	X	X
	Use thin fans to minimise garment distortion	NOT	X

X: Suggested by the participants. NOT: Not suggested by the participants.

). We explored these prioritised field study design considerations to propose the final cooling sportswear (Table 4 and Figure 5).

Table 6. Summary of the suggestions for developing low-cost cooling sportswear for athletes in developing and tropical countries.

Key Considerations	Explanations
Improve air circulation and air retention	Improve air circulation and air retention inside the sportswear when designing fan-cooling sportswear for outdoor tropical climate conditions. An integrated pre-cooled air supply to the fan-cooling unit can minimise environmental temperature influence on the fan-cooling effect when conducting prolonged outdoor activities.
User-technology interactions with sportswear	Consider designing technology controls that require physical interactions in easily reachable locations (switch in the glove/hand) of the sportswear and, whenever possible, design separate switches for separate functions, such as controlling the cooling level and switching it off. Consider exploring touchless command controls to improve user-technology interactions during sports.
Overall comfort, wearability and washability of cooling sportswear	Consider exploring textile-integrated smart technologies to design sportswear that are closely representing traditional sportswear while providing added smart technology-based functions. Consider washable textile integrated cooling technologies to improve washability and wearability.
Cost-effectiveness	Select cost-effective cooling technologies (fan cooling) when designing cooling sportswear for developing countries. Consider cooling sportswear that consist of both smart fan cooling and low-cost perforated panels in sweating zones to deliver cooling comfort with minimum cooling technology. Consider users’ key needs when designing cooling sportswear for developing countries rather than focusing on the latest or most popular technologies (e.g., simple cooling technology controlled by a switch).
Sustainability and cultural considerations	Sportswear with a minimum impact on the environment. Further, cultural belief/religion should be considered with sustainable and non-animal-based sportswear options

summarises the key insights for designing cooling sportswear. Figure 7 and Figure 8 show the diagram of the proposed cooling garment.

5. Discussion

The findings of this study demonstrate that the sportswear prototype increased the cooling comfort and sweat evaporation of the athletes when conducting outdoor cycling activities. These findings align with the performance of existing fan cooling studies [15,92]. Researchers evaluated inbuilt fan-cooling garments and proved that fan cooling could improve the cooling comfort of individuals in hot climatic conditions [92,93]. However, these existing fan cooling studies were mostly validated in the occupational context.

The average cooling comfort rating stated by our participants, “slightly cool” (M = −0.6), indicates that there is room for improvement in the cooling comfort provided by our prototype. Moreover, the study participants stated that when conducting prolonged sports activities in outdoor hot/humid climatic conditions, the air temperature affects the fan cooling effect and reduces the cooling comfort. This aspect related to fan cooling was not explored in existing studies.

To improve the cooling performance of the sportswear in tropical conditions, the participants suggested using pre-cooled air in the sportswear together with fan cooling. Researchers explored circulatory cooling units consisting of pre-cooled air to enhance the cooling comfort of individuals [14,94]. However, these concepts have not been explored to improve the cooling comfort of athletes during sports activities and consist of components such as a cooler unit that can increase the overall weight of the sportswear, ultimately affecting the comfort and portability of the athletes.

Clothing comfort during physical exercise is dependent on the materials and ergonomics of the sportswear [95]. The participants liked the detachable nature of the fan cooling unit, allowing them to wash the sportswear as an item of normal clothing. Designing smart technologies as detachable wearable accessories is a popular approach adhered to by smart wearable manufacturers [96], and researchers explored these smart accessories focusing on a wide variety of applications [97,98]. However, as further stated by our participants, having the cooling technology as a detachable unit can affect the wearability of the sportswear. Moreover, having to detach the smart unit before washing the sportswear is inconvenient for them. Considering this, the participants suggested exploring technologies that allow embedding a washable cooling technology into sportswear rather than having it as a detachable unit.

Researchers explored washable e-textiles to design smart technologies that closely represent traditional clothing [99,100]; however, due to the lack of appropriate testing methodologies and the premature state of the technologies, the washability performance of these technologies is still questionable [100]. Moreover, most of these advancements focusing only on a niche, high-end consumer markets that do not include low-income athletes living in developing countries. Moreover, to the best of our knowledge, researchers have not explored washable cooling technologies that consist of integrated electronic/electrical circuits. This highlights the importance of low-cost technologies that can embed smart functions into clothing without compromising clothing attributes.

The rough cost of our cooling sportswear is AUD 20, which is lower compared to existing popular smart cooling applications (USD 300 (AUD 400) to USD 8000 (AUD 10,800) (2016–2021)) [18,54]. We selected low-cost fan cooling technology [15,92] as the cooling technology for the prototype. Furthermore, regardless of the popularity of smart app-controlled smart technologies and sensor technology [101,102], our study participants did not consider these costly features as essential considerations needed in cooling sportswear to fulfil their cooling requirements. Moreover, we used low-cost perforated panels in the sportswear (in sweating zones) together with fan cooling technology to obtain cooling comfort with minimum cooling technology (costly) involvement.

Based on the study outcome, the main four attributes derived from cycling sportswear design were: functional, aesthetic, sustainability and cost. The design considerations related to the functional dimension were categorised into sixteen sub-attributes: cooling (cooling requirements (sufficient cooling, personalised cooling), design considerations for cooling technologies (smart and basic), cooling zones), user-technology interactions, powering, softness, lightweight, fit, durability, easy-care (handling, washing), sweat evaporation, stretchability, safety, and psychological comfort (due to unfamiliarity of smart sportswear, versatility, wearability, hydration, other smart functions (smart monitoring, smart compression, and communication)). The aesthetic attributes include design considerations that are related to the appearance of the sportswear and related technologies, technology, and symbolic expectations (team representation) of the athletes. The sustainability attributes include ethical design aspects that are related to the environment and ethical design. The cost attributes include design considerations related to affordability and perceived value.

5.1. Product Experience: Balance between Clothing Properties and Technology

The proposed sportswear for Sri Lankan athletes consists of a cooling unit to improve their cooling comfort. Electronic smart systems and clothing are perceived differently by consumers. An appropriate balance between smart functions and clothing properties is needed to ensure user satisfaction and acceptance [103,104]. Moreover, this balance can be influenced by the characteristics of the target consumers [103]. Regardless of the improved cooling comfort, Sri Lankan athletes (research participants) were not comfortable wearing unconventional, smart cooling sportswear consisting of circuit components and hard units. The lack of smart clothing and wearable technology product experience of the research participants made them unfamiliar with smart cooling sportswear, hence influencing their expectations from such sportswear. Concerning this, clothing/fashion properties should be given special attention when designing cooling clothing for athletes living in developing countries such as Sri Lanka, who have lower smart technology experience. Recent advancements in smart clothing, such as electronic yarns, printed circuits, and textile sensors, enable smart clothing designs that can offer smart functions without compromising consumer clothing expectations [105,106,107]. However, most of these advances focused only on the niche, high-end consumer markets that do not include low-income athletes living in developing countries such as Sri Lanka. This highlights the importance of low-cost technologies that can embed smart functions into clothing without compromising clothing attributes.

5.2. Caring for the Environment: Religion and Guilt-Free Sportswear Products

Study participants preferred sportswear with a minimum impact on the environment. Sustainability and ethical fashion are key components in responsible fashion initiatives that focus on designing and delivering clothing with minimal impact on the environment while ensuring maximum benefit to the fashion industry and society [108,109]. The participants suggested using recycled yarn to produce sportswear, reuse sportswear, and employ bio-degradable circuits to minimise the environmental impact that arises due to sportswear landfills. The environmental damage caused by fashion/clothing waste is widely discussed in the literature [110]. As mentioned by the participants, Sri Lanka’s small size can exacerbate this concern, and the recent accident caused in Sri Lanka due to a rubbish dump collapse is a piece of evidence for this situation [111]. Moreover, as stated by study participants, most Sri Lankan athletes are Buddhists who believe in Karma. According to Buddhist teachings, harming another living being can adversely affect their Karma [112]. Hence, Sri Lankan athletes preferred purchasing sportswear made without harming either animals or the environment. In line with this, Armstrong [113] explored how fashion can be influenced by Buddhist culture and emphasised the importance of environment-friendly and non-violent fashion practices. Given the above, it is important to design sustainable and non-animal-based sportswear options for athletes living in communities influenced by Buddhist cultures, such as Sri Lanka.

5.3. Limitations

The field study consisted of 30 min cycling trials to evaluate the performance of the prototype and to understand design considerations for cooling sportswear. The 30 min duration for the cycling trails was determined considering practical limitations associated with conducting longer cycling trials with athletes, while the COVID-19 restrictions limit the movements within Sri Lanka. It is recommended to evaluate the cooling sportswear in an actual cycling race that would continue for at least two hours. In addition, the sample size was small, and no women athletes were available for the study. A future study that measures physiological measurements such as a change in skin temperature, microclimate humidity, and core temperature of outdoor athletes due to fan cooling can add a new contribution to the literature. The smaller sample size employed in the study may have impacted the accuracy of the t-test analysis. Moreover, we did not conduct the power analysis necessary to ensure the statistical significance of the study results. However, the primary goal of this study was to analyse the in-depth qualitative feedback of the selected participant group, which was accomplished successfully. This study elaborated on a preliminary validation conducted to measure the cooling comfort of the prototype only using the perpetual responses of the participants. In our future studies, the prototype, which will be improved considering this study’s outcome, will undergo a final validation study incorporating both perceptual metrics and real-time body temperature measurements.

6. Conclusions and Future Work

This study explored the effectiveness of affordable cooling sportswear with endurance cycling athletes living in developing and tropical countries such as Sri Lanka. Results demonstrated that cooling sportswear consisting of fan cooling improved the cooling comfort, sweat evaporation, and overall comfort of endurance athletes during sports activities conducted in tropical climatic conditions. After examining user suggestions, we reviewed existing cooling technologies to find affordable solutions and minimise the overall cost of the cooling unit.

In order to improve the cost advantage further, the sportswear should be manufactured locally as much as using local materials. We also considered durability and versatility-related design aspects to further improve value for money. Even though the T-shirt needs to be replaced after a regular clothing lifetime (detachable and costly), the durable cooling unit can be used with another set of T-shirts for a longer duration. Moreover, since the cooling unit is attached to the T-shirt via a pocket construction, the athletes can use the sportswear as a normal T-shirt if desired.

Participants provided several design considerations for cooling sportswear, for example, (1) improving fan cooling in tropical climates by improving air retention/circulation and introducing pre-cooled air, (2) the importance of technologies that allow touchless control to improve user-technology interactions during sports, and (3) importance of washable textile embedded circuits to improve wearability and washability. Future work should focus on integrating the suggestions in designing cooling sportswear and evaluating its effectiveness in a longitudinal study.