Cardiopulmonary responses and muscle strength influence running performance parameters differently at different slopes

The analysis of trail-running performance appears to be complex and cardio-respiratory and muscular factors could have a variable importance depending on the inclination. Our study aims to determine the role of these parameters in performance. 13 subjects with heterogeneous levels participated in the study. They carried out 7 visits including 3 maximal aerobic speed (MAS) test at 1, 10 and 25% slope on treadmill, 3 endurance tests at 100% of the MAS reached at 1, 10 and 25% and an evaluation on isokinetic ergometer at different speeds (60-180-240 {\textdegree}/s). Gas exchange measured during the incremental tests. We were able to identify 2 groups, a performance and a recreational group. We observe a difference in VO2max, MAS at 1 and 10%, and maximal aerobic ascensional speed (MAaS) at 25%, between the 2 groups but no difference in VO2max and exhaustion time at 100% MAS between the different conditions (1-10-25%). Interestingly, at ventilatory thresholds the metabolic parameters, expressed as absolute or relative values, are similar between conditions (10-25%) while the ascensional speed are different. This study suggests that the measurement of ascensional speed is not as relevant as heart rate for controlling intensity given the variety of slope gradients in trail-running races

Ultrasound assessments of organs and blood vessels before and after 40 days isolation in a cavern (deep time experiment 2021)

Introduction: Spaceflight simulation studies like confinement in small volume habitat with limited physical activity have reported even after 60 days an abnormal arterial wall adaptation with increase thickness or stiffness. The purpose of the current study was to determine the effects on blood vessel and organ structure of 40 days of isolation in a huge habitat with intensive physical activity.Method: Data were collected from 14 individuals (7 male) who isolated in a cavern for 40-days while performing normal daily activities without time references. Ultrasound assessments were performed pre- and post-isolation using a teleoperated system with eight different acoustic windows to obtain 19 measurements on 12 different organ/vascular structures which included the common carotid artery, femoral artery, tibial artery, jugular vein, portal vein, bile duct, kidney, pancreas, abdominal aorta, cervical and lumbar vertebral distance, and Achilles tendon.Results: Common carotid artery measures, including the intima media thickness, stiffness index, and the index of reflectivity measured from the radiofrequency signal, were not changed with isolation. Similarly, no differences were found for femoral artery measurements or measurements of any of the other organs/vessels assessed. There were no sex differences for any of the assessments.Discussion: Results from this study indicate a lack of physiological effects of 40-days of isolation in a cavern, contrary to what observed in previous 60 days confinement. This suggests a potential protective effect of sustained physical activity, or reduced environmental stress inside the huge volume of the confined facility

Etude des facteurs déterminants la performance selon le degré de pente en trail-running

International audienc

Etude des facteurs déterminants la performance selon le degré de pente en trail-running

International audienc

Cardiopulmonary responses and muscle strength influence running performance parameters differently at different slopes

The analysis of trail-running performance appears to be complex and cardio-respiratory and muscular factors could have a variable importance depending on the inclination. Our study aims to determine the role of these parameters in performance. 13 subjects with heterogeneous levels participated in the study. They carried out 7 visits including 3 maximal aerobic speed (MAS) test at 1, 10 and 25% slope on treadmill, 3 endurance tests at 100% of the MAS reached at 1, 10 and 25% and an evaluation on isokinetic ergometer at different speeds (60-180-240 °/s). Gas exchange measured during the incremental tests. We were able to identify 2 groups, a performance and a recreational group. We observe a difference in VO2max, MAS at 1 and 10%, and maximal aerobic ascensional speed (MAaS) at 25%, between the 2 groups but no difference in VO2max and exhaustion time at 100% MAS between the different conditions (1-10-25%). Interestingly, at ventilatory thresholds the metabolic parameters, expressed as absolute or relative values, are similar between conditions (10-25%) while the ascensional speed are different. This study suggests that the measurement of ascensional speed is not as relevant as heart rate for controlling intensity given the variety of slope gradients in trail-running races

Power Is More Relevant Than Ascensional Speed to Determine Metabolic Demand at Different Gradient Slopes During Running

International audienceHingrand, C, Olivier, N, Combes, A, Bensaid, S, and Daussin, FN. Power is more relevant than ascensional speed to determine metabolic demand at different gradient slopes during running. J Strength Cond Res 37(11): 2298–2301, 2023—Trail running is characterized by successive uphill and downhill running sessions. To prescribe training intensity, an assessment of maximal running capacity is required. This study compared 2 uphill incremental tests using the same ascensional speed increment to identify the influence of the slope gradient on performance. Ten subjects (8 men and 2 women) performed 3 incremental exercises on various slope (1%: IT01, 10%: IT10, and 25%: IT25), and the ascensional speed increment was similar between IT10 and IT25 (100 m·h−1 every minute). Gas exchanges, heart rate, and power were monitored continuously during the tests. Similar V̇o2max levels were observed in the 3 conditions: 68.7 ± 6.2 for IT01, 70.1 ± 7.3 for IT10, and 67.6 ± 7.0 for IT25. A greater maximal ascensional speed was reached in the IT25 (1760 ± 190 vs. 1,330 ± 106 for IT25 and IT10, respectively, p < 0.01). A significant relationship was observed between relative V̇o2 levels and relative power without any effect of slope. Power should be the parameter used for prescribing training intensity compared with ascensional speed in trail

Analysis of Factors Associated With Continued Cooling of Core Temperature After Prolonged Cold-Water Swimming

Purpose: To assess the factors associated with continued cooling duration of core temperature () after prolonged outdoor cold-water swimming. Methods: We designed a cohort study among swimmers participating in an outdoor cold-water swim during qualifying for the English Channel Swim. The day before the event, the participants completed a demographic questionnaire, and body composition was measured using bioelectrical impedance analysis (mBCA 525, Seca). The swimming event consisted of laps over a 1000-m course, for up to 6 hours, in water at 12.5 to 13 °C. was measured using an ingestible temperature sensor (e-Celsius, BodyCap) during and up to 1 hour after the swim. Results: A total of 14 participants (38 [11] y; N = 14, n = 11 males, n = 8 in swimming costume and n = 6 in wetsuit) were included. Before swimming, was 37.54 (0.39) °C. The participants swam for an average of 194.00 (101.94) minutes, and mean when exiting the water was 35.21 (1.30) °C. The duration of continued cooling was 25 (17) minutes with a minimum of 34.66 (1.26) °C. Higher body mass index (r = .595, P = .032) and fat mass (r = .655, P = .015) were associated with longer continued cooling, independent of wetsuit wear. Also, the rate of drop during swimming (−1.22 [1.27] °C/h) was negatively correlated with the rate of gain after swimming (+1.65 [1.23] °C/h, r = −.682, P = .007). Conclusion: Increased body mass index and fat mass were associated with continued cooling duration after prolonged outdoor cold-water swimming at 12.5 to 13 °C. The rate of drop during swimming was negatively correlated with the rate of rewarming.</jats:p

Cardiopulmonary responses and muscle strength influence running performance parameters differently at different slopes

The analysis of trail-running performance appears to be complex and cardio-respiratory and muscular factors could have a variable importance depending on the inclination. Our study aims to determine the role of these parameters in performance. 13 subjects with heterogeneous levels participated in the study. They carried out 7 visits including 3 maximal aerobic speed (MAS) test at 1, 10 and 25% slope on treadmill, 3 endurance tests at 100% of the MAS reached at 1, 10 and 25% and an evaluation on isokinetic ergometer at different speeds (60-180-240 °/s). Gas exchange measured during the incremental tests. We were able to identify 2 groups, a performance and a recreational group. We observe a difference in VO2max, MAS at 1 and 10%, and maximal aerobic ascensional speed (MAaS) at 25%, between the 2 groups but no difference in VO2max and exhaustion time at 100% MAS between the different conditions (1-10-25%). Interestingly, at ventilatory thresholds the metabolic parameters, expressed as absolute or relative values, are similar between conditions (10-25%) while the ascensional speed are different. This study suggests that the measurement of ascensional speed is not as relevant as heart rate for controlling intensity given the variety of slope gradients in trail-running races