ECSS Paris 2023: CP-AP26
INTRODUCTION: Athletes are often required to perform intensive training sessions under hot environment. Exercise under hot environment increases physiological stress due to elevated core temperature and dehydration (Silva et al. 2019). Therefore, recovery process becomes more important following the exercise under hot environment. Although several types of the post-exercise recovery strategies are proposed, sleep is indispensable to promote recovery of exercise capacity (John et al. 2017). While the effects of exercise on sleep have been well documented, how endurance exercise under hot environment affects sleep quality remains unclear. The aim of the present study was to clarify the effect of endurance exercise under hot environment on sleep quality, nocturnal body temperature and autonomic nerve activity. METHODS: Ten endurance male athletes (20±1years, 169.8±5.7cm, 61.2±7.3kg, VO2max 56.1±4.9ml/kg/min) performed 60 min of endurance exercise at two different conditions, (1) hot condition (HOT：35℃,50%RH), (2) control condition (CON : 20℃,50%RH). After completing the exercise, sleep variables (evaluated by EEG), skin temperature and heart rate variability (HRV) were measured during sleep. RESULTS: Total sleep time (TST), sleep efficiency (SE) and time of slow wave sleep (N3) were significantly greater in HOT (TST: 411.3±15.6; SE: 97.1±3.7%; N3: 107.7± 31.0 min) compared with CON (TST: 389.8±34.6; SE: 92.3±8.1%; N3: 93.6±20.6 min, p<0.05 for each variable). The changes in skin temperature during initial 180 min after the sleep onset did not differ significantly between conditions. When comparing autonomic nerve activity parameters (evaluated by HRV) during sleep, no significant differences were observed between conditions for HF, LF/HF, SDNN, RMSSD, or pNN50 during sleep. However, NN50 was significantly lower in the HOT (127.5±39.2) compared with CON (138.0±30.4, p<0.05) . CONCLUSION: Our findings indicate that endurance exercise under hot environment improved sleep quality compared with the same exercise under thermoneutral environment in endurance athletes. However, changes in body temperature and autonomic nerve activity during sleep did not account for improved sleep quality following the exercise under hot environment. References Chase, J., Roberson, P., Saunders, M., Hargens, T., Womack, C., & Luden, N. (2017). One night of sleep restriction following heavy exercise impairs 3–km cycling time–trial performance in the morning. Applied Physiology, Nutrition, & Metabolism, 42 (9), 909–915. Silva, R., Barros, C., Mendes, T., Garcia, E., Valenti, V., De Abreu, L., Garner, D., Espindola, S., & Penha–Silva, N. (2019). The influence of a hot environment on physiological stress responses in exercise until exhaustion. PLoS ONE, 14 (2), e0209510.
Read CV Tomotaka NatsuiECSS Paris 2023: CP-AP26
INTRODUCTION: Performance in long-distance events is influenced by several key physiological factors, including maximum oxygen uptake (VO₂max), running economy (RE), and the percentage of VO₂max at which the aerobic and anaerobic thresholds occurred [1]. Previous studies found differences in aspects such as the percentage of VO₂max where lactate threshold occurs between different level runners [2]. Therefore, this intervention aimed to analyze physiological differences between performance levels to better understand their influences on key performance parameters in long-distance runners. METHODS: Thirty-four male and 22 female runners were categorized into two groups based on the 50th percentile of WA scores from 5 km to half-marathon events. Group 1 included runners with 965.18 ± 67.14 points for females and 933.06 ± 40.82 points for males. Group 2 averaged 652.55 ± 134.15 points for females and 737.41 ± 109.88 points for males. A maximal graded exercise test on a treadmill (HP Cosmos Pulsar, Germany) was performed, starting at 10 km·h⁻¹ for females and 12 km·h⁻¹ for males, increasing by 1 km·h⁻¹ per minute until exhaustion and at 1% of inclination. Respiratory variables were measured with a gas analyzer (CPX Ultima MedGraphics, United States), and heart rate (HR) was recorded using a Polar H10 monitor. Ventilatory thresholds (VT1, VT2), VO₂max, and maximal aerobic speed (MAS) were determined. Independent t-tests were conducted separately for males and females to compare performance groups. RESULTS: At the VT1, significant differences between groups were found in speed (p<0.001), %MAS where VT1 occurs (p=0.019), HR (p=0.01), and RPE (p=0.016) for male participants. In contrast, for female participants, there were only significant differences between groups in the speed (p=0.008). At the VT2, significant differences between groups were observed in speed (p=0.022) and HR (p=0.03) for male participants. For female participants, there were significant differences in speed (p<0.001) and VO₂ (ml/kg/min) (p=0.018). CONCLUSION: Male and female runners with higher performance levels demonstrated higher absolute speeds at both VT1 and VT2, as well as a higher %MAS where VT1 occurs only in male runners. Additionally, HR and RPE were significantly higher in males with a higher performance level, which may be attributed to their ability to sustain greater relative intensity over the same duration. These findings highlight the importance of stratifying athletes by performance level when analyzing physiological responses. REFERENCES 1. Joyner, M.J. Modeling: optimal marathon performance on the basis of physiological factors. J Appl Physiol (1985) 1991, 70, 683-687, doi:10.1152/jappl.1991.70.2.683. 2. Støa, E.M.; Helgerud, J.; Rønnestad, B.R.; Hansen, J.; Ellefsen, S.; Støren, Ø. Factors Influencing Running Velocity at Lactate Threshold in Male and Female Runners at Different Levels of Performance. Front Physiol 2020, 11, 585267, doi:10.3389/fphys.2020.585267.
Read CV Alejandro Alda-BlancoECSS Paris 2023: CP-AP26
INTRODUCTION: Trail running has emerged as a growing trend in endurance sports and has seen significant professionalization among many athletes (1). As with other endurance sports, neuromuscular factors play a crucial role in performance (2). However, most reviews in the scientific literature address physiological topics and injuries, leaving a gap in the knowledge regarding neuromuscular factors. Therefore, the purpose of this scoping review was to identify which neuromuscular factors have been studied, the types of interventions that have been conducted, and the populations that have been analyzed. METHODS: A systematic search was conducted on PubMed, Web of Science, and Dimensions databases composing “trail running” AND “strength” OR “resistance” OR “neuromuscular” OR “lower limb” as keywords. Two reviewers screened the articles for eligibility according to the inclusion criteria. The articles that did not include trail athletes were excluded and PEDro scale was used to check article’s quality. RESULTS: Eighty-four records were retrieved during an initial search with a total of 38 finally included. Most of the studies had a pre-post design (44.73%), followed by cross-over studies (26.31%), comparative (10.53%), correlational (10.53%), and longitudinal case studies (7.89%). The main topic was to analyze the effect of different trail running distances, slopes, and sex on neuromuscular fatigue. Maximal voluntary and evoked contractions of lower limb muscles were measured in most of the studies (73.68%). Electromyography (21.05%), leg stiffness (15.79%), jump performance (13.16%), muscle soreness questionnaires (10.53%), and levels of creatine kinase (5.26%) were also evaluated. Moreover, fewer than half of the studies included female participants, and while some focused on amateur or high-level/elite athletes, the majority involved well-trained and experienced individuals. CONCLUSION: The effects of trail running fatigue on neuromuscular factors have been widely studied across different distances, sexes, and athletic levels. Similarly, the impact of neuromuscular and biomechanical factors on performance, although to a lesser extent, has also been examined. However, there is a lack of knowledge regarding the impact of strength training on trail running performance, as well as a general need for further research involving female populations. References 1. Scheer, V., Basset, P., Giovanelli, N., Vernillo, G., Millet, G. P., & Costa, R. J. S. (2020). Defining Off-road Running: A Position Statement from the Ultra Sports Science Foundation. Int j sport med, 41(5), 275–284. 2. Downhill Running: What Are The Effects and How Can We Adapt? A Narrative Review. Sports Med. 2020 Dec;50(12):2083-2110.
Read CV Violeta Muñoz de la CruzECSS Paris 2023: CP-AP26