Search Results (240)

Background: Exercise duration at maximum oxygen uptake ($\dot{\mathrm{V}̇}$O₂max) appears to be influenced not only by metabolic factors but also by the interplay between brain dynamics and ventilatory regulation. This study examined how cortical activity, assessed via electroencephalography (EEG), relates to performance and acute fatigue regulation during a constant-load cycling test. We hypothesized that oscillatory activity in the theta, alpha, and beta bands would be associated with ventilatory coordination and endurance capacity. Methods: Thirty trained participants performed a cycling test to exhaustion at 90% maximal aerobic power. EEG and gas exchange were continuously recorded; ratings of perceived exertion were assessed immediately after exhaustion. Results: Beta power was negatively correlated with time spent at $\dot{\mathrm{V}̇}$O₂max (r = −0.542, p = 0.002). Theta and Alpha power alone showed no direct associations with endurance, but EEG–metabolic ratios revealed significant correlations. Specifically, the time to reach $\dot{\mathrm{V}̇}$O₂max correlated with Alpha/$\dot{\mathrm{V}̇}$O₂ (p < 0.001), Alpha/$\dot{\mathrm{V}̇}$CO₂ (p < 0.001), and Beta/$\dot{\mathrm{V}̇}$CO₂ (p = 0.002). The time spent at $\dot{\mathrm{V}̇}$O₂max correlated with Theta/$\dot{\mathrm{V}̇}$O₂ (p = 0.002) and Theta/$\dot{\mathrm{V}̇}$CO₂ (p < 0.001). The time-to-exhaustion was correlated with Theta/$\dot{\mathrm{V}̇}$CO₂ (p < 0.001) and Alpha/$\dot{\mathrm{V}̇}$CO₂ (p < 0.001). Conclusions: These findings indicate that cortical oscillations were associated with different aspects of acute fatigue regulation. Beta activity was associated with fatigue-related neural strain, whereas Theta and Alpha bands, when normalized to metabolic load, were consistent with a role in ventilatory coordination and motor control. EEG–metabolic ratios may provide exploratory indicators of brain–metabolism interplay during high-intensity exercise and could help guide future brain-body interactions in endurance performance. Full article

Objectives: The optimal rehabilitation protocol following open reduction and internal fixation (ORIF) for Neer type-4 valgus impacted proximal humeral fractures (VIPHF) remains controversial. This study aimed to compare the long-term efficacy and safety of early active mobilization versus conventional rehabilitation in these patients. Methods: We conducted a retrospective cohort study at a single tertiary hospital involving 128 patients who underwent ORIF for Neer type-4 VIPHF between January 2018 and December 2022. Participants were divided into two groups based on the rehabilitation protocol received: the Early Active Activation (EAA) group (n = 64), which initiated controlled active exercises on postoperative day 1, and the Conventional Rehabilitation (CR) group (n = 64), which followed a delayed protocol. The primary outcome was the Constant–Murley score at 24 months. Secondary outcomes included scores at 3, 6, and 12 months, pain VAS scores, active range of motion, fracture healing time, and complications. Results: The EAA group demonstrated significantly superior outcomes, including a higher 24-month Constant–Murley score (88.7 ± 6.5 vs. 75.3 ± 9.2, p < 0.001), lower VAS scores at all time points (p < 0.001), greater range of motion (p < 0.001), and shorter fracture healing time (10.2 ± 1.8 vs. 12.5 ± 2.3 weeks, p < 0.001). Complication rates did not differ significantly (4.7% vs. 6.3%, p = 0.718). Conclusions: For patients with surgically stabilized Neer type-4 VIPHF, early active rehabilitation initiated on postoperative day 1 was associated with significantly improved functional outcomes, accelerated recovery, and a favorable safety profile. However, these findings should be interpreted with caution due to the retrospective design, single-center setting, and potential residual confounding. Further validation through prospective, multicenter studies is recommended. Full article

Background/Objectives: Bone reconstruction using megaprostheses is increasingly performed following bone tumour resections, including sarcomas, to enhance patient outcomes and quality of life. However, this is a complex patient group, and there is little consensus as to postoperative rehabilitation and associated outcomes. Methods: A systematic search was conducted in MEDLINE and EMBASE databases according to the Implementing Prisma in Exercise, Rehabilitation, Sport medicine and SporTs science (PERSiST) guidelines. Studies describing rehabilitation protocols and functional outcomes following bone tumour resection and modular oncologic megaprosthesis reconstruction were included. All papers were individually assessed for methodological quality using the Joanna Briggs Institute (JBI) critical appraisal tool. Results: The search generated 105 records, 28 underwent full-text review, and 13 studies were included. Available data reflect 371 patients with a mean age of 49.17 (S.D. 21.40) years and a mean postoperative follow-up of 41.88 (S.D. 32.88) months. Surgical indications were documented as sarcomas in 9 studies, and tumour metastasis to the bone in 10 studies. Rehabilitation protocols were reported in 5 studies following proximal humerus resection with a mean dislocation rate of 14.5% (S.D. 5.26). All protocols advised brace immobilisation for a period ranging between 10 days and 6 months. Superior Constant-Murley shoulder score was reported in patients with early active isometric exercises at 6 weeks. Six studies reported proximal femur prosthesis rehabilitation and functional outcomes, with a mean dislocation rate of 10% (S.D. 9.82). Enhanced outcomes were reported in studies employing early mobilisation. Two studies assessed distal femur prosthesis; both studies reported similar protocols with full weight bearing 3 weeks following surgery. The methodological quality of the studies varied, but was overall modest, with 10/13 studies meeting at least 50% of JBI reporting criteria. Conclusions: The existing literature on rehabilitation and outcomes in orthopaedic oncology patients following arthroplasty with megaprosthesis is limited, with rehabilitative protocols variably described. However, it seems that early active mobilisation does not increase the risk of joint dislocations or infections. Full article

Direct measurement of heat loss in a moving limb requires attached heat-flux sensors, which are strongly affected by convection and radiation. Skin calorimetry minimizes these effects, enabling an accurate measurement. A skin calorimeter was used to measure the heat flux in the rectus femoris (thigh) of a subject exercising for 30 min at a mechanical power of 80 W. In this work, we have developed an analytical model able to describe the thermal evolution of the rectus femoris during exercise and subsequent recovery. This model consists of a sum of two exponentials f(t) = A₁(1 − e^−t/τ) + A₂·t·e^−t/τ, with the novelty that the second term is a linear–exponential, which opposes the first term, and that allows the initial thermal transient characterization. The time constants are the most relevant parameters, with mean values of 5 min during exercise and 10 min during recovery (for the 4 cm² sensing area). The mean exercise amplitude (A₁) is 1.1 mW/W, while in post-exercise it is −0.8 mW/W. In addition, the measurement of the thermal resistance of the skin before and after exercise allowed for the estimation and analysis of the evolution of the subcutaneous internal temperature, which follows the same exponential function. The developed mathematical model defines a Transfer Function (TF)—a potential invariant that can predict the thigh’s heat flux response to any exercise protocol (for the subject analyzed). This mathematical approach may be useful for sports and clinical applications. Full article

Background/Objective: Paprika xanthophylls (PXs) have potent antioxidant properties and are believed to improve oxygen delivery (DO₂) efficiency by enhancing red blood cell (RBC) deformability. This study investigated whether PX ingestion improves endurance performance and subsequently enhances cognitive function by improving brain microcirculation. Methods: A crossover design was used to compare the effects of PX ingestion and a control condition in 21 healthy college students (18 males, 3 females). Each participant served as their own control, completing both conditions in a randomized order with a one-month washout period to eliminate any carryover effects. The participants underwent an incremental load test, a constant load test, the Trail Making Test Type B (TMT-B), and the Stroop test (ST). Results: In the incremental tests, the PX group showed a significantly lower heart rate (p = 0.032) and higher exercise efficiency (EE) (p = 0.004). In the constant load test, heart rate was lower (p = 0.020), and EE was higher (p = 0.030). No significant between-group differences were found in the cognitive tests; however, the PX group showed significant improvements in the TMT-B (p = 0.034) and ST interference rate I (p = 0.040). Conclusions: It is speculated that PX intake may improve DO₂ efficiency, which could contribute to the observed enhancements in endurance performance and, in turn, positively affect cognitive function by optimizing the brain’s oxygenation state. However, due to the absence of a placebo control group and unmeasured RBC deformability and cerebral blood flow, as well as a significant male predominance, this study’s results should be interpreted with caution. Full article

Objectives: This study investigates the biomechanics of the bench press and overhead press exercises by modeling the trunk and upper limbs as a kinematic chain of rigid links connected by revolute joints and actuated by single- and two-joint muscles, with motion constrained by the barbell. The aims were to (i) assess the different contributions of shoulder and elbow torques during lifting, (ii) identify the parameters influencing joint loads, (iii) explain the origin of the sticking region, and (iv) validate the model against experimental barbell kinematics. Methods: Equations of motion and joint reaction forces were derived analytically in closed form. Dynamic simulations produced vertical barbell velocity profiles under various conditions. A waveform similarity analysis was used to compare simulated profiles with experimental data from maximal bench press trials. Results: The sticking region occurred when shoulder torque dropped below a critical threshold, resulting in a local velocity minimum. Adding elbow torque reduced this dip and shifted the velocity minimum from 38 cm to 23 cm above the chest, although it prolonged the time needed to overcome it. Static analysis revealed that grip width and barbell constraint had a greater effect on shaping the sticking region than muscle architecture parameters. Elbow extensors contributed minimally during early lift phases but became dominant near full extension. Model predictions showed high similarity to experimental data in the pre-sticking (SI = 0.962, p = 0.028) and sticking (SI = 0.949, p = 0.014) phases, with reduced, non-significant similarity post-sticking (SI = 0.881, p > 0.05) due to the assumption of constant torques. Conclusions: The model offers biomechanical insight into how joint torques and barbell constraints shape movement. The findings support training strategies that target shoulder strength early in the lift and elbow strength near lockout to minimize sticking and improve performance. Full article

The superiority of Variable Resistance Training (VRT) over traditional Constant Resistance Training (CRT) for enhancing lower-limb performance is debated, with previous meta-analyses limited by aggregating disparate exercises. This systematic review and meta-analysis, the first to focus exclusively on the squat, compared the acute and long-term effects of VRT versus CRT on maximal strength and explosive power. Following PRISMA guidelines, 20 studies were analyzed (literature search up to 15 June 2025), with Hedges’ g used for effect size (ES) calculation. Results demonstrated VRT’s superiority for both acute (ES = 0.34) and long-term adaptations. Acutely, effects peaked with an 8–12 min recovery (ES = 0.43). Long-term, VRT produced greater gains in maximal strength (ES = 0.31) and explosive power (ES = 0.17). Subgroup analyses on maximal strength revealed that elastic bands were highly effective (ES = 0.67), particularly in trained individuals (ES = 0.35), males (ES = 0.41), within cycles < 8 weeks (ES = 0.44), and at frequencies of ≤2 sessions/week (ES = 0.45). For explosive power, chains were most effective (ES = 0.37), significantly improving jumping performance but not sprinting. In conclusion, VRT is a more effective modality for squat training; optimal programs should utilize elastic bands for strength and chains for power, with strength-focused blocks being short-term (<8 weeks) and lower-frequency (≤2 sessions/week) for trained individuals. Full article

Background: In recent years, the use of compression garments has expanded into sports contexts to enhance performance and optimize post-exercise recovery. One of the most investigated physiological variables for evaluating their effectiveness has been peripheral muscle oxygenation, a crucial indicator of physical performance. However, studies regarding the effects of compression on the upper limbs remain limited and the topic is insufficiently explored. Therefore, the aim of this study was to analyze the effects of compression garments on muscle oxygen saturation (SmO₂) recovery in the biceps brachii after brief maximal isometric contractions. Specifically, physiological responses were compared between two conditions (with and without compression garments), hypothesizing that compression would promote faster and more efficient muscle reoxygenation compared to traditional clothing. Methods: Fourteen male participants (mean age: 24.4 years; mean height: 176.75 cm; mean body mass: 73 kg) performed three 10 s isometric contractions separated by 180 s passive recovery periods under compression (CG) and non-compression (noCG) conditions. SmO₂ was monitored using near-infrared spectroscopy (NIRS), assessing Half-Recovery Time (HRT), Overshoot Amplitude, Initial Slope, and the time constant τ. Results: The compression garment significantly reduced HRT (CG 8.52 s vs. noCG 10.21 s; p = 0.035), significantly increased Overshoot Amplitude (CG 21.40% vs. noCG 7.92%; p = 0.0014), resulted in a greater Initial Slope (CG 2.43%/s vs. noCG 2.09%/s; p = 0.027), and significantly reduced the time constant τ (CG 11.68 s vs. noCG 21.04 s; p < 0.001). Conclusions: The use of compression garments demonstrated significant improvements in post-exercise muscle oxygen saturation, suggesting potential advantages for muscle recovery and positive implications for athletic performance. Full article

This paper explores the link between the results of the UK’s Research Evaluation Exercises (REEs) and university decisions on which Units of Assessment (UOA) to submit to in future REEs. How the raw data from REEs can be converted into two novel measurements of research performance—an internal and an external measurement—is explained. Data on two UOAs, Business and Management Studies (BMS) and Economics and Econometrics (E&E), from five consecutive REEs undertaken in the United Kingdom (UK) between 1992 and 2014, was then used to assess whether and how the results of one REE were related to UOA submissions in the next. The findings reveal that both the internal and external assessments of performance were associated with changes in the probability of resubmission to the same UOA in the next REE, with the external comparisons being particularly important. It also appears that while one instance of poor performance might be tolerated by a university, repeated poor performance was associated with a heightened risk of withdrawal from both the BMS and E&E UOAs in the next REE. In addition, holding research performance constant, universities were significantly more likely to withdraw from the E&E UOA than the BMS UOA. New (post-1992) universities were also more likely to continue to submit to a UOA in the next REE than pre-1992 institutions. There is also some evidence that the quality of submissions to the BMS UOA is catching up with that of submissions to the E&E UOA. The somewhat worrying implications of these findings for the health of the Economics discipline in UK universities are assessed. Full article

Objectives: A pulsed electromagnetic field (PEMF) induces electric currents in biological tissue, enhancing muscle energy expenditure during heavy constant-load exercises. In this paper, we investigate the PEMF effect on muscular activation in male sedentary people. Methods: The surface electromyographic (EMG) activity of the right leg’s vastus medialis (RVM) and biceps femoris (RBF) muscles was recorded and analyzed. The root mean square values were normalized to the peak amplitude observed during maximal voluntary contraction. Measurements were taken at baseline (stationary seated position), during warm-up (unloaded cycling), and throughout 15 min of constant-load exercise performed at moderate intensity. Subjects performed two experimental conditions, when PEMF was turned ON versus OFF. Results: No significant difference was found during the baseline. The analysis during warm-up showed significant differences between conditions (ON vs. OFF) for both muscles (RVM p = 0.019; RBF p < 0.001). The analysis during constant-load exercise showed significant differences between conditions (ON vs. OFF) for RVM only (p = 0.002). Conclusions: This study provides evidence that PEMF stimulation acutely enhances muscle activation, primarily in the vastus medialis, with a comparatively smaller effect on the biceps femoris during moderate-intensity cycling in sedentary young men. The observed increase in EMG activity suggests that PEMF may facilitate neuromuscular excitability and muscle recruitment, potentially through mechanisms related to calcium signaling and enhanced muscle perfusion. Full article

Objectives: The aims of the presented study were to investigate and compare the effectiveness of Low-Level Laser Therapy (LLLT) and therapeutic ultrasound (US) on pain, function, emotional status, and sleep disturbances in patients with rotator cuff tendinopathy (RCT). Method: A total of 84 patients with RCT were included in the study and randomly divided into the US group (n = 42) and the LLLT group (n = 42). Hot-pack, transcutaneous electrical nerve stimulation, and a home-based exercise program were also administered to patients in each group. The patients were evaluated at baseline, and at 1st, 4th, and 12th weeks after treatment by Visual Analog Scale (VAS), Shoulder Pain and Disability Index (SPADI), Constant Murley Score (CMS), Disabilities of the Arm, Shoulder, and Hand Questionnaire (DASH), Hand Grip Strength (HGS), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Pittsburgh Sleep Quality Index (PSQI), and Short Form-36 (SF-36). Results: Significant improvements in VAS, SPADI, CMS, DASH, BDI, BAI, PSQI, and SF-36 scores were observed over time in both groups (p < 0.05 for all). The improvements in HGS scores were significantly greater in the US group compared to the LLLT group (p < 0.05 for all). There were no statistically significant differences between the groups in VAS, SPADI, CMS, DASH, BDI, BAI, PSQI, and SF-36 scores at each time point (p > 0.05 for all). Conclusions: Both therapeutic US and LLLT are effective and safe in the treatment of patients with RCT. However, our findings indicate no superiority of one treatment over the other in terms of pain relief or improvements in function, emotional status, sleep disturbances, or quality of life. Full article

The present review summarizes the effects of manipulating different resistance exercise variables on jumps, sprints, and changes of direction (CODs) in soccer. Regarding jumps, moderate-to-high loads, full range of movement (ROM), non-failure sets, and a moderate training volume are recommended. Different external resistances like constant-load, flywheel, or elastic bands, as well as various movement velocities and select exercises, are equally effective. As for sprints, moderate-to-high loads, constant load or flywheel but not elastic resistances, movements performed at full ROM, non-failure sets, and moderate-to-high training volume might be more effective, while numerous movement velocities and exercises could be chosen. As for CODs, moderate-to-high loads, flywheel more than constant-load resistance, and a moderate-to-high total number of repetitions are recommended, while several movement velocities and exercises could be selected, though ROM needs investigation. The effectiveness of concentric-only vs. eccentric-only training on jumps, sprints, and CODs has not been investigated, while an external focus and inter-set rest > 2 min are theoretically preferable, albeit not proven. Importantly, high movement velocity is not a prerogative of effectiveness, and limited ROM is not associated with sport-specific patterns such as jumps. Practitioners in soccer may manipulate resistance exercise variables depending on the purpose. Full article

The noticeable growth of road transport means that the protection of road infrastructure is becoming a critical issue. The main factor leading to the excessive degradation of roads are overloaded vehicles. The effective elimination of such vehicles from road traffic is possible through widespread usage of Weigh-In-Motion (WIM) systems for direct mass enforcement, thus eliminating the need for “manual” vehicle checks which are currently carried out by the appropriate services. WIM mass enforcement systems require strict metrological control, meaning that an initial verification, conducted at the moment when the system is installed, and subsequent periodic verifications are required. These operations aim to ensure that vehicle weighing error is consistently maintained within a permissible range of values. Fulfilment of this condition allows for the minimisation of the probability that a vehicle loaded within normative limits will be classified as overloaded. The long-term study of two WIM systems located on provincial road 975 in Wielka Wies, in southern Poland, equipped with load sensors made using different technologies (strain gauge sensors and quartz sensors) and in different weather conditions, has allowed us to formulate recommendations regarding the frequency with which subsequent verifications should be performed in order to ensure the reliability of the weighing results. This paper presents the results of these studies and conclusions formulated based on them; in this case, they showed a verification of the system can be performed every 8 months. The conclusions and recommendations that we have presented concern primarily those WIM stations which were the object of our study and caution should be exercised when generalising these to other cases. Its novelty results from several premises. For the first time, long-term studies of two WIM systems equipped with load sensors made with different technologies were carried out. Both systems were installed on the same surface, in the immediate vicinity of each other. They were installed on a standard road and were subjected to the constant impact of road traffic with identical parameters. Tests of both WIM systems were performed periodically, using the pre-weighed vehicles method, in different seasons, for a period of 15 months. During the tests, the same test vehicles drove through both WIM systems at the same speed. All of this resulted in the obtainment of a unique set of measurement data, the analysis of which allowed for the assessment and comparison of the proprieties of the load sensors made with both technologies. Full article

Background: Branched-chain amino acids (BCAAs, isoleucine, leucine, and valine) are commonly applied to promote muscle protein synthesis. However, the effects of BCAAs on exercise-induced substrate metabolism, performance and post-exercise fatigue during endurance exercise remain unclear. Methods: In a double-blind cross-over design, eleven active males completed 1 h of constant load exercise (CLE) at 60% VO₂max power followed by a time to exhaustion (TTE) test at 80% VO₂max power after supplementation with BCAAs or placebo on consecutive three days. During exercise, indirect calorimetry was used to measure the carbohydrate (CHO) and fat oxidation rate, as well as the cycling efficiency. In addition, rating of perceived exertion (RPE) and visual analogue scale (VAS) scores were obtained at interval times during the whole period. Fingertips and venous blood (n = 8) were collected for the measurement of metabolic responses at different time points during exercise. Results: Compared to the placebo group, the fat oxidation rate was significantly higher after 20 and 30 min of CLE (p < 0.05). The CHO oxidation rates showed a significant increase in the BCAA group during TTE (p < 0.05). Meanwhile, the cycling efficiency during TTE was significantly improved (p < 0.05). Interestingly, VAS significantly decreased post-exercise in the BCAA group (p < 0.05). Additionally, the levels of blood insulin between the two groups were significantly higher in the post-exercise period compared to the pre-exercise periods (p < 0.001), while insulin levels were significantly lower in the post-exercise period with supplemental BCAAs compared to the placebo (p < 0.001). BCAAs also enhanced the levels of blood ammonia in the post-exercise period compared to the fasting and pre-exercise periods (BCAA: p < 0.01; Placebo: p < 0.001). However, in the post-exercise period, blood ammonia levels were significantly lower in the BCAA group than in the placebo group (p < 0.05). Conclusions: This study shows the critical role of BCAAs during exercise in active males and finds that BCAA supplementation enhanced fat oxidation during the CLE, increased carbohydrate oxidation and exercise efficiency during the TTE, and reduced immediate post-exercise fatigue. Full article

This study investigated the sustainability aspects of implementing a small-scale biogas digester project at the EARTH Centre, a horse-riding facility for the disabled, in South Africa. Firstly, an energy audit of the facility was conducted. From this exercise, energy-saving opportunities through anaerobic digestion of horse manure were identified. Biomethane potential tests (BMPs) were then performed using the Automatic Methane potential test system II (AMPTS II) of BioProcess Control (Lund, Sweden). The horse manure BMP result was 106 L/kg.VS with the biogas averaging a methane content of 40%. This BMP was lower than that of common substrates such as cow manure which can range from 150–210 L/kg.VS. The gas production rate was almost constant in the first 13 days indicating a long hydrolysis period for horse manure. The microbial species in the digester did not change much during the incubation period although small changes were visible in the proportions of each species as the reaction progressed from start to finish. The energy audit showed that 47% of the EARTH Centre’s energy requirements, which equated to 14,372 kWh/year, could be secured from biogas or solar instead of obtaining it from the national grid which is powered mainly by unsustainable coal-fired systems. As a starting point, a 10 cubic meter biogas digester was installed to produce 5512 kWh of energy per year in the form of biogas. To boost biogas production and continue running the system smoothly, it was evident that the horse manure-fed digester would require regular spiking with cow manure as a bioaugmentation strategy. The digester also produced bio-fertiliser and several sustainable development goals were fulfilled by this project. Current efforts are focused on process optimization of this technology at the Earth Centre to further improve the sustainability of the whole business. Full article