Search Results (181)

Maximum aerobic capacity (MAC) helps in physical work capacity evaluation. In practice, the construction jobs are designed using the standard treadmill or ergometer MAC value, which is inappropriate and leads to injuries. According to NIOSH, the average oxygen consumption during an 8 h day is recommended to be no more than 33% of the exercise-specific MAC. Therefore, there is a necessity for construction activity-specific MAC exercise protocols and estimation models. The aim of the study is to develop MAC estimation models for common construction activities such as walking, carrying, lifting, and combined (carrying, dragging, hammering, lifting, and wrenching) using the submaximal exercise test mode. Ten male participants performed all four activities at three different intensities for five minutes each. The oxygen uptake and heart rate were recorded for each trial. This study shows that the average MAC value for walking, carrying, lifting, and combined activities is 0.779 gpm (2.95 L/m), 0.674 gpm (2.55 L/m), 0.745 gpm (2.82 L/m), and 0.608 gpm (2.30 L/m), respectively. The MAC value of combined construction activities is significantly lower than walking (28%), carrying (11%), and lifting (22%). The study recommends using a construction activity-specific exercise protocol for evaluating jobs or workers to prevent a mismatch between job demands and worker capabilities. Full article

Microbial lipid production from renewable carbon sources, particularly lignocellulosic hydrolysates, is a promising alternative to plant-derived oils and fats for food applications, as it can minimize the land use by utilizing agricultural wastes and byproducts from food production. In this context, a standard approach to prevent oxygen limitation at reduced air gassing rates during long-term aerobic microbial processes is to operate bioreactors at increased pressure for elevating the gas solubility in the fermentation broth. This study investigates the effect of absolute pressures of up to 2.5 bar on the conversion of the carbon sources (glucose, xylose, and acetate), growth, and lipid biosynthesis by Cutaneotrichosporon oleaginosus converting a synthetic nutrient-rich lignocellulosic hydrolysate at low air gassing rates of 0.1 vessel volume per minute (vvm). Increasing pressure delayed xylose uptake, reduced acetic acid consumption, and reduced biomass formation. Lipid accumulation decreased with increasing pressure, except for fermentations at 1.5 bar, which achieved a maximum lipid content of 83.6% (±1.6, w/w) (weight per weight in %). At an absolute pressure of 1.5 bar, a lipid yield from glucose, xylose, and acetic acid of 38% (w/w) was reached after 6 days of fermentation. The pressure sensitivity of C. oleaginosus may pose challenges on an industrial scale due to the dynamic changes in pressure when the yeast cells pass through the bioreactor. Increasing liquid heights in full-scale bioreactors will result in increased hydrostatic pressures at the bottom, substantially reducing lipid yields, e.g., to only 23% (w/w) at 2.0–2.5 bar, as shown in this study. However, further scale-up studies with dynamic pressure regimes (1–2.5 bar) may help to evaluate scale-up feasibility. Full article

Previous studies suggest that the cortisol awakening response (CAR) shows a biphasic pattern—either an increase or a blunting—in response to exercise involving overload, potentially reflecting physiological adaptation. However, its response to continuous high-intensity exercise under controlled experimental conditions has not been sufficiently investigated. This pilot case series examined daily CAR changes during a 10-day high-intensity cycling protocol (20 min/day at 80% of maximal oxygen uptake [$\dot{V}{O}_2\max$]) in two healthy male participants. The CAR increased during Days 1–4 and returned to baseline levels from Day 5 onward, showing similar trends in acute physiological responses. $\dot{V}{O}_2\max$ and/or maximum workload improved following the intervention. These findings support the methodological feasibility of longitudinal CAR monitoring during short-term high-intensity exercise under controlled experimental conditions and suggest that CAR may be a promising non-invasive biomarker for assessing short-term physiological adaptation. Full article

Papermaking sludge, rich in intrinsic resource value, is effectively barred from direct deployment in environmental remediation, agriculture, or energy generation by its pronounced contaminant burden. Pyrolytic conversion into high-value paper sludge biochar, such as papermaking sludge biochar (PSBC) provides a green, efficient portal for closing its resource loop. In this study, papermaking sludge was converted into a series of paper sludge biochars (PSBCs) via oxygen-limited pyrolysis at 500–900 °C. The porous architecture, surface physicochemical properties, and crystalline structure of the biochars were comprehensively characterized, and their performance for aqueous tetracycline (TC) removal was systematically quantified. Pyrolysis at 900 °C afforded PSBC 900 with the lowest yield (36.05%) yet the highest Brunauer–Emmett–Teller (BET) surface area (79.53 m²/g), an extensively developed mesopore network, and the greatest degree of graphitization. Across an initial tetracycline (TC) concentration window of 20–160 mg/L, PSBC 900 delivered an equilibrium capacity (q_e) of 72.22 mg/g, outperforming PSBC 700 and PSBC 500 by factors of 1.3 and 1.8, respectively. Optimal uptake was achieved at a dosage of 1.0 g/L, pH 7, and 120 min contact time. Among the background cations examined, Mg²⁺ exerted a pronounced inhibitory effect, whereas Na⁺, K⁺, and Ca²⁺ exerted negligible interference. The adsorption process was accurately described by the pseudo-second-order kinetic model and the Langmuir isotherm (R² > 0.999), yielding a theoretical maximum capacity (q_m) of 76.39 mg/g for PSBC 900 at 313 K. Thermodynamic parameters ($∆{\mathrm{G}}^{\mathsf{\theta }}$ < 0, $∆{\mathrm{H}}^{\mathsf{\theta }}$ > 0, $∆{\mathrm{S}}^{\mathsf{\theta }}$ > 0) confirm a spontaneous, endothermic, and entropy-driven process. After five consecutive adsorption–desorption cycles, PSBC 900 retained >64.68% of its original efficiency, demonstrating excellent regenerability. Paper sludge biochar enables a “waste-to-treat-waste” strategy for the efficient abatement of tetracycline, offering an economically viable and high-performance technology that advances the remediation of tetracycline-laden wastewaters. Full article

A quaternized and phenyl-functionalized hyperbranched PEI-based sponge (S_HPEI-QP) was successfully prepared, and its adsorption performance was investigated to evaluate its potential for removing the anionic non-steroidal anti-inflammatory drug (ibuprofen (IBU)). We reported that the synthesis of polyethyleneimine-based sponges was achieved through cryo-polymerization using 1,4-butanediol diglycidyl ether (BDDE) as the crosslinking agent. Subsequent functionalization with resorcinol diglycidyl ether (RDGE) and trimethylamine introduced quaternary ammonium cations, imparting strong basicity and hydrophilicity, as well as phenyl groups, conferring hydrophobic characteristics, respectively. The aforementioned sponge material, S_HPE-QPI, primarily facilitates the efficient adsorption of IBU in aqueous solutions through the anion exchange properties of quaternary ammonium groups and the π-π interactions associated with oxygen-activated benzene rings. Various characterizations, such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and specific surface area determination method (BET), confirmed the successful synthesis of the bifunctionalized S_HPEI-QP adsorbent. This adsorbent features a porous structure (specific surface area of 77.2 m² g⁻¹ and pore size distribution of 25–100 nm) and an isoelectric point (pH_pzc) of 9.38. The adsorption kinetics of the adsorbent for IBU were extremely rapid and conformed to a pseudo-second-order kinetic model, and the adsorption isotherm aligned with the Langmuir isotherm model. Noteworthily, S_HPEI-QP demonstrated an exceptionally high adsorption capacity for IBU, achieving a maximum uptake of 905.73 mg g⁻¹ at pH 7.0, which surpassed that of most of the previous reported adsorbents. Moreover, the sponge material can be chemically regenerated. After eight cycles of use, the adsorption efficiency decreased by only 4%. These findings suggest that the synthesized dendritic anion exchange adsorbent represents a promising candidate for the removal of IBU from contaminated water sources. Full article

In this study, two native microalgae, Chlorella sp. MC18 (CH) and Scenedesmus sp. MJ23-R (SC) were cultivated in bubble column photobioreactors for wastewater treatment. Domestic wastewater (DWW) was used as the main culture medium, alone (100%) and blended (10%) with vinasse, whey, or agro-food waste (AFW), respectively. Both species thrived in 100% DWW, achieving significantly high removal efficiencies for chemical oxygen demand, total nitrogen, and total phosphorus. Mineral removal exceeded 90% in all blended systems, highlighting the strong nutrient uptake capacity of both strains. The maximum specific growth rate (µ_max) in 100% DWW was higher for SC than in standard BG11 medium, and supplementation with vinasse, whey, or AFW further increased µ_max for both species. Blending DWW significantly enhanced microalgal biomass and lipid production compared to 100% DWW. Lipid production (max., 374 mg L⁻¹), proximate lipid composition (max., 30.4%), and lipid productivity (max., 52.9 mg L⁻¹ d⁻¹) significantly increased in all supplemented cultures relative to DWW alone, demonstrating the potential of co-substrate supplementation to optimize microalgal cultivation. This study contributes to reducing the water footprint and fills a gap in the bioprocessing potential of algae-based systems, highlighting wastewater blending as a circular economy-aligned approach that supports sustainable bioprocesses and resource recovery. Full article

Objectives: We examined how opposing running slopes can modulate interval training effects on aerobic performance and reduction–oxidation (REDOX) determinants. Methods: Fourteen physically active volunteers, assigned to either the Uphill group (UG) or the Downhill group (DG), completed 16 workouts of ten 30-s runs, at either +10% or −10% grade, with a work-to-rest ratio of 1:2 at 90% of their Maximum Aerobic Speed (MAS) over 8 weeks. Maximal oxygen uptake (VO_2max), MAS, Running Economy (RE), time to exhaustion at MAS (Tmax), respiratory exchange ratio (RER), and blood lactate at rest, 5th, and 10th runs were evaluated pre-, mid-, and post-training. Also, REDOX markers [Total Antioxidant Capacity (TAC), Protein Carbonyls (PCs) were assessed in blood samples taken at rest and 3 min post-exercise of the first and last workouts. Results: VO_2max was unchanged in both groups; in the DG, MAS increased (from 14.2 ± 1.7 to 15.0 ± 1.5 km/h, d = 0.43), and post-training RER significantly increased (from 1.06 ± 0.07 to 1.12 ± 0.03). In the last training session, blood lactate levels increased in the UG (from 9.30 ± 2.69 mmοl/L to 13.34 ± 4.64 mmοl/L) but remained low and unchanged in DG (<2 mmοl/L). Post-training, resting TAC decreased in both groups, and the exercise-induced rise in PC levels was attenuated. Conclusions: Despite the brief intervention, VO₂max levels were maintained in both groups, with divergent changes in metabolic, REDOX, and performance indicators; uphill HIIT may serve for enhancing lactate tolerance, while downhill intermittent running may improve running economy. Full article

This longitudinal study aimed to examine the in-season variations in morphological, cardiorespiratory, muscular, and motor fitness components in junior male basketball players during an 8-month competitive season. Eighteen male basketball players (16.56 ± 0.90 years) were tested at three time points (T1, T2, T3). Assessed variables included body fat (BF), fat-free mass (FFM), muscle mass (MM), total body water (TBW), maximal oxygen uptake (VO₂max), final running speed in the 30-15 Intermittent Fitness Test (VIFT), maximum and average heart rate (HRmax, HRavg), squat jump (SJ), countermovement jump with arm swing (CMJmax), drop jump (DJ), 20 m sprint with 5 m and 10 m splits, T-test (TT), and Lane Agility Drill (LAD). Significant improvements were observed in body mass (T1–T3, p = 0.002; T2–T3, p = 0.039), along with reductions in BF (T1–T2 and T1–T3, p < 0.05) and increases in FFM and MM (especially T2–T3, p < 0.05). VO₂max increased significantly from T1 to T2 and T3 (p < 0.01), while HRaverage decreased across all intervals (p < 0.001), and HRmax declined slightly from T1 to T3 (p = 0.031). VIFT improved significantly between T1 and both T2 and T3 (p < 0.001). Measures of explosive strength (SJ, CMJmax, DJ) and agility (TT, LAD) showed consistent improvement across the season (p < 0.001), with moderate gains from T2 to T3 (p < 0.01 for SJ). These findings suggest meaningful physical and physiological adaptations during the competitive season, highlighting the importance of structured and continuous training throughout critical phases of athletic development in junior basketball players. Full article

Introduction: Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children. It is believed that children with JIA have lower cardiopulmonary capacity and worse exercise tolerance. The gold standard for assessing physical fitness is aerobic fitness, commonly referred to as the maximum or peak oxygen uptake volume (peakVO₂) measured during a maximum load exercise test. Reduced aerobic fitness may play a key role in predicting the health of JIA patients as it has been associated with cardiovascular diseases and increased adult mortality. Methods: The aim of this study was to assess the oxygen capacity of adolescents with JIA along with other cardiopulmonary parameters in order to determine a group of patients with increased risk of developing cardiovascular diseases in comparison with healthy individuals. Patients were assessed based on parameters such as age, sex, type of JIA, laboratory parameters, physical activity, and treatment. Results: Patients with JIA had lower median values of peakVO₂ (29.05 vs. 38.02 mL/min/kg, p < 0.001), as well as other crucial cardiopulmonary parameters, such as O₂ pulse, minute ventilation, oxygen uptake efficiency slope, and cardiac output than in the healthy control group. The ventilatory anaerobic threshold was achieved earlier and at lower VO₂ values in children with JIA (p = 0.0001). Children with JIA also had lowered respiratory parameters such as maximal voluntary ventilation (p = 0.0031) and tidal volume (p = 0.0002). Patients who were physically active (moderate-intensity physical activity lasting at least 60 min per day) had significantly higher peakVO₂ (p = 0.0099) and ΔVO₂/ΔWR relationship (p = 0.0041) values than JIA patients who were not physically active. Conclusions: Children with JIA show moderate to severe physical impairment. Reduced physical fitness and a low level of activity might be associated with further deterioration of patient’s condition, which might contribute to increased risk of cardiovascular disease, social exclusion and deterioration of quality of life in this group of patients. Exercise programs that improve aerobic fitness and increase muscle strength should be individualized and modified based on the individual needs and capabilities of the patient. Full article

Background: The multifactorial nature of CrossFit performance remains incompletely understood, particularly regarding sex- and experience-related physiological and biomechanical factors. Methods: Fifteen trained athletes (8 males, 7 females) completed assessments of anthropometry, estimated one-repetition maximums (bench press, back squat, deadlift), squat jump (SJ), maximal oxygen uptake (VO₂max), ventilatory responses ($\dot{\mathrm{V}}$E), and heart rate (HR). Spearman, Pearson, and partial correlations were calculated with Holm and false discovery rate (FDR) corrections. Results: Males displayed greater body mass, lean and muscle mass, maximal strength, and aerobic capacity than females (all Holm-adjusted p < 0.01). Experienced athletes completed Fran faster than beginners despite broadly similar anthropometric and aerobic profiles. In the pooled sample, WOD time showed moderate negative relationships with estimated 1RM back squat (ρ = −0.54), deadlift (ρ = −0.56), and bench press (ρ = −0.65) before correction; none remained significant after Holm/FDR adjustment, and partial correlations controlling for training years were further attenuated. Conclusions: This exploratory study provides preliminary evidence suggesting that maximal strength may contribute to Fran performance, whereas conventional aerobic measures were less influential. However, given the very small sample (n = 15, 8 males and 7 females) and the fact that no relationships remained statistically significant after correction for multiple testing, the results must be regarded as preliminary, hypothesis-generating evidence only, requiring confirmation in larger and adequately powered studies. Full article

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: Adolescence is a pivotal stage of development characterized by significant physical, psychological, and social changes. Establishing healthy lifestyle habits during this period is crucial for long-term health and the prevention of chronic diseases. Despite this, global trends show a marked decline in physical activity among adolescents, particularly girls, who are more susceptible to sedentary behaviors. One potential site for intervention to eliminate physical inactivity at the population level is the school educational setting during childhood. Traditional school-based physical exercise programs often adopt a one-size-fits-all approach, which may not address the diverse needs and interests of students, leading to reduced motivation and participation. Personalized physical exercise programs, tailored to individual capabilities and preferences, offer a promising alternative to enhance physical fitness and foster lifelong engagement in physical activity. Methods: A total of 170 Hungarian high school girls (mean age ≈ 15.3 years) were randomly assigned to either a personalized physical exercise group or a control group following the standard curriculum. The intervention spanned two academic years and consisted of five traditional gym classes per week (control group) or three traditional and two individually tailored classes with cardiorespiratory and resistance training per week (intervention group), each lasting 45–60 min. Individual goals were set based on baseline assessments, emphasizing self-referenced progress. Results: The personalized physical exercise group showed significant improvements in body mass index (BMI), body fat percentage, maximum oxygen uptake capacity (VO₂max), muscular strength, and flexibility (p < 0.05), while the control group exhibited minimal or negative changes. Conclusions: The personalized physical exercise program has been shown to be more effective in achieving higher cardiorespiratory performance and favorable body composition among adolescent girls than a traditional school physical education class, highlighting its potential role in school settings. Full article

The transition period in football can negatively affect players’ fitness indicators. However, if appropriate training programs are implemented during this period, these effects can be reversed. The purpose of this study was to investigate the effect of a high-frequency exercise program during the transition period on aerobic capacity, isokinetic torque of the lower limbs, jumping ability, and body composition. The transition period was divided into two phases: the first phase lasted two weeks and involved complete rest from exercise, and the second phase lasted four weeks during which the players completed three aerobic-focused training sessions and two maximum strength training sessions per week. A total of 13 young football players (age 17.8 ± 0.7 years, height 1.78 ± 0.07 m, weight 70.3 ± 8.4 kg) participated in the study. A paired samples t-test was applied, and statistical significance was set at p < 0.05. The results showed that players improved their maximal oxygen uptake (VO₂ max) after the program (p = 0.037, t = −2.348). The performance in countermovement jump performance and in the isokinetic torque of the right quadriceps showed a decline (p = 0.009, t = 3.112 & p = 0.004, t = 2.299, respectively), while no changes were observed in any other parameter (p > 0.05). The findings suggest that a program with these characteristics can counteract the negative effects typically observed during the transition period. Moreover, with specialized stimuli, improvement may also be observed during the transitional period. Full article

Background: Spinal muscular atrophy (SMA) is a neurodegenerative disorder caused by variants in the SMN1 gene. This study investigates the functional and biochemical effects of moderate-intensity aerobic exercise in SMA Type III patients. Methods: Twenty-three patients aged 18–57 years were included in this study. The training group underwent a 12-week aerobic exercise program using a bicycle ergometer at 60–70% of their maximum heart rate three times per week for 30 min per session. The training continued for an additional four months. The primary outcome measures were the six-minute walk distance and oxygen uptake, both reflecting exercise capacity. Secondary outcome measures included muscle strength with dynamometer, functional performance, and fatigue with different scales. Furthermore, serum survival motor neuron (SMN) protein and insulin-like growth factor-1 (IGF-1) hormone levels were measured at baseline, post-training first measurement (after 12 weeks), and post-training second measurement (after 28 weeks). Results: The exercise group showed a significant increase in exercise capacity (p < 0.001) and 6MWT walking distance (p = 0.003). Furthermore, reduction in walking time in the 10-m walk test (p = 0.019) and improvements in strength of the right and left quadriceps (p = 0.004, p = 0.031) and right gastrocnemius (p = 0.034) muscles were identified. Furthermore, an improvement in the Fatigue Severity Scale (FSS) (p = 0.037) was found. SMN protein and IGF-1 levels were increased in the second measurement in the training group (p = 0.022 and p = 0.016, respectively). Conclusions: An aerobic exercise program improved physical function and muscle strength and reduced fatigue in SMA Type III patients, with sustained biochemical improvements. Aerobic exercise may serve as a beneficial adjunct therapy for this population. Full article

Aim: To investigate the synergistic effects of exercise training and Brassica oleracea var. italica (broccoli sprout) supplementation on Apolipoprotein A-I, B-100, and J levels in men with Type 2 diabetes mellitus (T2DM). Methods: Forty-four males with T2DM were randomly assigned to four groups: Control (CG), Supplement (SG), Training (TG), and Training + Supplement (TSG) groups. Participants in the supplement groups (SG and TSG) received 10 g of broccoli supplement after meals for 12 weeks, while those in the training groups (TG and TSG) participated in a structured exercise program (resistance and aerobic), performed three times per week for 12 weeks, at intensities of 60–70% one-repetition maximum (1RM) for resistance training and 60–70% peak oxygen uptake (VO_2peak) for aerobic training. Results: Circulating levels of apolipoproteins improved after 12 weeks in the TSG, TG, and SG groups. However, the TSG group exhibited the most pronounced improvements across metabolic and lipoprotein markers, reflecting an additive effect of both interventions. Specifically, the TSG group demonstrated absolute reductions in ApoB-100 (−48.30 ± 7.20 mg/dL) and ApoJ (−44.05 ± 5.76 mg/dL), along with an increase in ApoA-I (+44.92 ± 6.05 mg/dL). Main effect analysis revealed that exercise training elicited the most substantial improvements across metabolic and lipoprotein markers, with large effect sizes for glucose (η²p = 0.787), insulin (η²p = 0.640), HOMA-IR (η²p = 0.856), ApoA-I (η²p = 0.685), ApoB-100 (η²p = 0.774), ApoJ (η²p = 0.848), and HDL-C (η²p = 0.535). Supplementation showed moderate effects, particularly on HOMA-IR (η²p = 0.370), ApoA-I (η²p = 0.383), and ApoB-100 (η²p = 0.334), supporting an additive but exercise-dominant benefit. The combined intervention group (TSG) showed the most pronounced improvements across all measured outcomes, with large effect sizes for ApoA-I (η²p = 0.883), glucose (η²p = 0.946), insulin (η²p = 0.881), HOMA-IR (η²p = 0.904), and ApoJ (η²p = 0.852). Conclusions: The effects of combining training and broccoli sprout supplementation on apolipoprotein levels are likely to result from the activation of two separate pathways, one from training and the other from supplementation. This dual-modality intervention could serve as an effective complementary strategy in managing metabolic and cardiovascular risk factors for individuals with T2DM. However, the magnitude of change induced by the combination of exercise training and broccoli supplementation was largely driven by the training component, with supplementation providing complementary but less consistent benefits. Full article