Abstract Objectives The purpose was to directly assess in-competition thermoregulatory responses in recreational runners during a city marathon conducted in cool, ambient conditions using a two-pill ingestion strategy. Methods Thirty-two recreational runners (age: 38.7 ± 10.2 years, mass: 73.9 ± 11.0 kg, height: 177 ± 8 cm) were invited to participate in this study. Core temperature was continuously assessed using telemetric ingestible pills. Each runner swallowed two pills: the first pill (Pill 1) 11 h:47 min ± 1 h:01 min pre-race (before overnight sleep) and the second (Pill 2) 2 h:35 min ± 0 h:54 min pre-race (on wakening). Results Pre-race core temperature for Pill 1 was significantly different from Pill 2, with values of 37.4 ± 0.4 °C and 37.1 ± 0.6 °C, respectively (p=0.006). The mean core temperature during the race was higher for Pill 1 compared to Pill 2 (38.5 ± 0.5 °C and 37.8 ± 1.0 °C, respectively; p<0.001). Peak core temperature was higher for Pill 1 compared to Pill 2 (39.1 ± 0.5 °C and 38.8 ± 0.5 °C, respectively; p=0.03). Post-race core temperature was higher for Pill 1 compared to Pill 2 (38.8 ± 0.7 °C and 38.1 ± 1.3 °C, respectively; p=0.02). Conclusions The timing of pill ingestion significantly impacted core temperature and hence timing of pill ingestion should be standardised (5 h:30 min–7 h prior to measurement). Despite the relatively cool ambient conditions during the race, a significant number of runners achieved a high core body temperature (≥39 °C), which was not accompanied by any signs of heat illness.

Abstract Objectives To investigate the impact of acute energetic stress (acute HIIE and fasting) on ERRγ, PPARβ, NR1D1, NR4A1, and TFEB in human skeletal muscle. Methods The current study performed secondary analyses using muscle biopsy samples from two previously published studies: study 1) leg muscle biopsies from nine men and eight women were obtained pre and 3 h following acute high-intensity interval cycling exercise (HIIE); study 2) leg muscle biopsies were obtained from nine men pre-, during, and post-an 8 h fast with or without 2 h of arm ergometer exercise. RT-PCR was performed on samples from each study to determine the mRNA expression of ERRγ, PPARβ, NR1D1, NR4A1, and TFEB. Additionally, we retrieved data from meta-analyzed human muscle gene expression using the publicly available database MetaMex. Results PGC-1α (p<0.01, d=1.98) and NR4A1 (p<0.01, d=1.36) mRNA expression significantly increased while TFEB (p≤0.05, d=0.70) decreased following HIIE. Significant decreases in NR4A1 and NR1D1 mRNA expression were observed following an 8 h fast. Our MetaMex analyses revealed significant increases (p<0.05) in PGC-1α and NR4A1 expression following aerobic and resistance exercise, and in PPARβ expression following resistance exercise. Conclusions Our data indicate that acute HIIE stimulates increases in NR4A1 and PGC-1α and decreases in TFEB mRNA expression in human skeletal muscle. Additionally, a short term (8 h) fast reduced the mRNA expression of the transcriptional regulators NR4A1 and NR1D1 – potentially as a mechanism of decreasing mitochondrial biogenesis to reduce energy expenditure during a period of restricted energy availability.

Abstract Introduction Runners from East Africa including Kenya, Ethiopia and Uganda have dominated middle- and long-distance running events, for almost six decades. This narrative review examines and updates current understanding of the factors explaining the dominance of East Africans in distance running from a holistic perspective. Content The dominance of East African distance runners has puzzled researchers, with various factors proposed to explain their unparalleled success. Four key elements emerge: 1) biomechanical and physiological attributes, 2) training characteristics, 3) psychological motivations, and 4) African diet. Runners from East Africa often exhibit ectomorphic somatotypes, characterized by lean body compositions which lead them to an extraordinary biomechanical and metabolic efficiency. Their sociocultural lifestyle, training regimens beginning at a young age with aerobic activities, seem crucial, as well as moderate volume, high-intensity workouts at altitudes ranging from 2,000 to 3,000 m. Psychological factors, including a strong motivation to succeed driven by aspirations for socioeconomic improvement and a rich tradition of running excellence, also contribute significantly. A multifactorial explanation considering these factors, without a clear genetic influence, is nowadays the strongest argument to explain the East African phenomenon. Summary and outlook To unravel the mystery behind the supremacy of East African runners, it is imperative to consider these multifaceted factors. The predominantly rural lifestyle of the East African population underscores the importance of aligning modern lifestyles with the evolutionary past of Homo sapiens, where physical activity was integral to daily life. Further research is required to explain this phenomenon, with a focus on genetics.

Abstract Objectives This study aimed to investigate the protective effects and underlying mechanisms of aerobic intermittent exercise on cognitive impairment by PM2.5 exposure. Methods Thirty-two rats were randomly divided into four groups: sedentary, exercise, sedentary + PM2.5 exposure, and exercise + PM2.5 exposure. The exercise groups underwent 8 weeks of exercise training (5 days of exercise per week). Subsequently, PM2.5 exposure groups were subjected to PM2.5 for three weeks. Post-exposure, we assessed cognitive abilities (shuttle box test), hippocampal tissue structure, related inflammatory factors (TNF-α, IL-6, IL-1β), the protein of inflammatory responses mechanism (P65, IκκB) and cognitive-related protein levels (BDNF, Aβ-42). Results PM2.5 exposure caused cognitive impairment, abnormal histopathological changes, reduced cognitive related protein and increased pro-inflammatory cytokine levels. Analysis of shuttle box test data revealed significant main effects on the passive avoidance latency times measured in rats (p<0.05). Aerobic intermittent exercise improves spatial learning decline in rats induced by PM2.5. Conversely, the Exercise + PM2.5 group demonstrated a significant reduction in latency of 24.9 % compared to the Sedentary + PM2.5 group (p<0.05, ES=1.41). Conclustion Aerobic intermittent exercise may be protect the decreased cognitive ability induced by PM2.5 exposure.

Abstract Objectives Independent mobility (IM), which is defined as the freedom of children moving without adult supervision, has been found to be positively associated with physical activity (PA). This study explored IM by sociodemographic factors and type of neighborhoods and its association with PA among children in Hong Kong. Methods A convenience sample of 330 children aged 8–12 years and their parents was recruited. The children wore an ActiGraph accelerometer for eight consecutive days to measure PA and sedentary time (ST). Parents reported parents’ license and children self-reported their actual mobility. Generalized estimating equations were conducted to examine the associations of IM with sociodemographics (e.g., children’s age, sex, body weight status, parents’ age, sex, maternal education) and type of neighborhood. Linear mixed models were performed to determine the associations of IM with PA and ST. Results Valid data from 296 children (8.8±0.6 years old, 42.2 % boys) were included in analysis. Children residing in sprawl and rural areas had greater parents’ license and actual mobility than those in urban areas. Greater parents’ license was associated with more moderate-to-vigorous intensity PA (MVPA) on weekend days (β=1.33, 95% CI: 0.15–2.51), while children’s actual mobility was positively associated with MVPA on weekdays (β=1.14, 95% CI: 0.10–2.18). Conclusions In densely populated metropolis, children living in highly urbanized areas with higher SES experienced reduced parental license and actual mobility compared to their peers in less affluent neighborhoods, irrespective of the level of urbanization.

Abstract Background and Aims The Union Cycliste Internationale has deemed transgender female athlete’s ineligible for the female category due to concerns about performance advantages. We conducted a follow-up analysis on laboratory-based performance indicators of sports performance using data from a longitudinally assessed transgender woman athlete undergoing gender-affirming hormone therapy (GAHT). Methods We evaluated laboratory performance indicators in transgender and cisgender women athletes using dual-energy X-ray absorptiometry scanning, handgrip strength measurement, jump testing, and cardiopulmonary exercise. Additionally, we assessed a transgender sub-elite cyclist before and after undergoing GAHT. Results After one year of GAHT, the transgender athlete showed declines in handgrip strength (7–13 %), countermovement jump (23–29 %), and V̇O2max (15–30 %). After 3 months, several performance indicators (absolute handgrip, peak power, relative peak power, average power, relative average power, V̇O2max and relative V̇O2max) were above the mean of cisgender female athletes, while others (Relative handgrip, countermovement jump and relative countermovement jump) were below. Similar trends were observed at 6 months and 1 year. Summary This hypothetical analysis, although with limited evidence, suggests the transgender athlete could compete equitably in elite cycling events within the female category after one year of GAHT. Adjustments based on competition data would ensure fairness. Further analysis after an additional 12 months is recommended to assess the impact of 2 years of GAHT. An outright ineligibility for the female category for transgender women athletes would hinder a true assessment of performance fairness.

Abstract Objectives Caveolin-3 (Cav-3) plays a pivotal role in maintaining skeletal muscle mass and function. Mutations or deletions of Cav-3 can result in the development of various forms of myopathy, which affect the integrity and repair capacity of muscle fiber membranes. However, the potential effect of Cav-3 on myofiber type composition remains unclear. Methods To investigate the effect of Cav-3 on muscle strength and running capacity, we examined the grip force test and the low/high-speed running test. Oxidative and glycolytic myofiber-related genes, proteins, and skeletal muscle fiber composition were measured to determine the role of the Cav-3 in oxidative myofiber formation. Results We report the impact of Cav-3 on enhancing muscle endurance performance in female mice, and the discovery of a new physiological function to increase the proportion of slow-twitch oxidative muscle fiber by analyzing the gastrocnemius and soleus. Skeletal muscle-specific ablation of Cav-3 in female mice increased oxidative myofiber-related gene expression and type I oxidative myofiber composition, with resultant improvements in endurance performance. In male mice, the absence of Cav-3 in skeletal muscle reduced in the expression of glycolytic fiber-related genes and proteins. Conclusions This study identified Cav-3 as a regulator of slow-twitch oxidative muscle fiber formation acting on female mice, which may provide a potential target for improving muscle oxidative function.

Abstract Objectives This research based on the theoretical framework of globalisation focuses on the development of gender equality policy in the Olympic Movement and the implementation of IOC’s gender equality policy in the context of Chinese elite volleyball. Methods In addition to documentary analysis, 17 semi-structured interviews were conducted with key insiders within Chinese elite volleyball system to provide a comprehensive understanding of the IOC’s gender equality policy implementation. The analysis involved perspectives of athletes’ participation, coaching positions, and leadership roles according to three main elements of the IOC’s gender equality policy. Results The findings demonstrated that the responses of Chinese elite volleyball to IOC’s gender equality policy are participative, conflictual, and passive in terms of the gender balance of athletes’ participation, coaches’ positions, and the representation of leadership roles respectively. Conclusions IOC recommended subordinated stakeholders including NOCs to implement gender equality policy. The attitude of Chinese elite volleyball governing body towards gender equality is generally positive. However, IOC’s gender equality policy is not consistently transferred at national level. Policy might be implemented with symbolic measure in China without monitoring system. Referees should be included in policy contents in addition to athletes, coaches and leaders. In addition, since IOC’s gender equality policy and statistics have been keeping updated, further results with respect to the case of volleyball should be demonstrated in future research.

Abstract Objectives Whether low-load resistance training (RT) without muscle failure, with or without blood flow restriction (BFR), is sufficient to increase strength and muscle growth of calf muscles in trained individuals is still unclear. This study aimed to compare the effects of low-intensity BFR RT vs. traditional low-intensity RT (noBFR) with moderate training volume on strength and circumference. Methods We designed a parallel, randomized controlled trial including 36 RT-trained participants (BFR: 7 females, 32.9 ± 8.8 years, 11 males, 28.4 ± 3.6 years; noBFR; 8 females, 29.6 ± 3.4 years; 10 males, 28.6 ± 4.9 years) who underwent eight weeks of twice-weekly low-load RT with 16 weekly RT sets (30 % of one-repetition maximum [1RM]). RT consisted of bilateral calf raises and seated unilateral calf raises, each conducted with 4 sets (30, 15, 15, 15 repetitions not to failure) of either BFR or noBFR. Outcome measures included calf circumference (CC), leg stiffness (LS), and various strength tests (seated and standing calf raise 1RM, isokinetic strength of plantar- and dorsiflexion). Results There were no significant interactions or group effects for most measures. Both groups showed significant improvements in seated calf raise strength (p=0.046, η 2 p=0.17). Pairwise comparisons indicated moderate to large effect sizes for strength improvements (standardized mean differences: 0.35–1.11), but no changes in calf circumference were observed in either group. Conclusions Low-load RT with and without BFR are useful to increase strength without necessarily affecting hypertrophy. Low-intensity BFR training did not confer additional benefits over traditional low-intensity RT for calf muscle strength or circumference, questioning its general advantage under such conditions.