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Purpose: We evaluated (1) whether participating in middle- and long-distance running races augments muscle soreness, oxygen cost, respiration, and exercise exertion during subsequent running, and (2) if post-race menthol application alleviates these responses in long-distance runners., Methods: Eleven long-distance runners completed a 1500-m race on day 1 and a 3000-m race on day 2. On day 3 (post-race day), either a 4% menthol solution (Post-race menthol) or a placebo solution (Post-race placebo) serving as a vehicle control, was applied to their lower leg skin, and their perceptual and physiological responses were evaluated. The identical assessment with the placebo solution was also conducted without race participation (No-race placebo)., Results: The integrated muscle soreness index increased in the Post-race placebo compared to the No-race placebo (P < 0.001), but this response was absent in the Post-race menthol (P = 0.058). Oxygen uptake during treadmill running tended to be higher (4.3%) in the Post-race placebo vs. No-race placebo (P = 0.074). Oxygen uptake was 5.4% lower in the Post-race menthol compared to the Post-race placebo (P = 0.018). Minute ventilation during treadmill running was 6.7-7.6% higher in the Post-race placebo compared to No-race placebo, whereas it was 6.6-9.0% lower in the Post-race menthol vs. Post-race placebo (all P ≤ 0.001). The rate of perceived exertion was 7.0% lower in the Post-race menthol vs. Post-race placebo (P = 0.007)., Conclusions: Middle- and long-distance races can subsequently elevate muscle soreness and induce respiratory and metabolic stress, but post-race menthol application to the lower legs can mitigate these responses and reduce exercise exertion in long-distance runners., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: This study investigated the effects of water temperature on cardiorespiratory responses and exercise performance during immersed incremental cycle exercise until exhaustion., Methods: Ten healthy young men performed incremental cycle exercise on a water cycle ergometer at water temperatures (T w) of 18, 26 and 34 °C. Workload was initially set at 60 W and was increased by 20 W every 2 min for the first four levels and then by 10 W every minute until the subject could no longer continue., Results: During submaximal exercise (60-120 W), [Formula: see text] was greater at T w = 18 °C than at 26 or 34 °C. Maximal workload was lower at T w = 18 °C than at 26 or 34 °C [T w = 18 °C: 138 ± 16 (SD) W, T w = 26 °C: 157 ± 16 W, T w = 34 °C: 156 ± 18 W], whereas [Formula: see text]O2peak did not differ among the three temperatures [T w = 18 °C: 3156 ± 364 (SD) ml min(-1), T w = 26 °C: 3270 ± 344 ml min(-1), T w = 34 °C: 3281 ± 268 ml min(-1)]. Minute ventilation ([Formula: see text]) and tidal volume (V T) during submaximal exercise were higher at T w = 18 °C than at 26 or 34 °C, while respiratory frequency (f R) did not differ with respect to T w., Conclusion: Peak workload during immersed incremental cycle exercise is lower in cold water (18 °C) due to the higher [Formula: see text] during submaximal exercise, while the greater [Formula: see text] in cold water was due to a larger V T.

Twenty minutes of voluntary hypocapnic hyperventilation prior to exercise reduces the aerobic metabolic rate with a compensatory increase in the anaerobic metabolic rate without affecting exercise performance during the Wingate anaerobic test (WAnT). Thus, pre-exercise hypocapnic hyperventilation may be a useful means of stressing the anaerobic energy system during training, ultimately improving anaerobic exercise performance. However, it remains unclear whether a shorter (e.g., 5 min) pre-exercise hypocapnic hyperventilation is sufficient to reduce the aerobic metabolic rate during high-intensity exercise. We therefore compared the effects of 5-min and 20-min pre-exercise hypocapnic hyperventilation on aerobic metabolism during the 30-s WAnT. Ten healthy young males and one female performed the WAnT following 20 min of spontaneous breathing (control trial) or 5 or 20 min of voluntary hypocapnic hyperventilation. Both the 5-min and 20-min hyperventilation reduced end-tidal CO2 partial pressure (an index of arterial CO2 partial pressure) to ∼23 mmHg, whereas it remained unchanged during the spontaneous breathing. The peak, mean and minimum power outputs during the WAnT did not differ among the three trials. Oxygen uptake during the WAnT was lower in both the 5-min (1493 ± 257 mL min−1) and 20-min (1397 ± 447 mL min−1) hyperventilation trials than during the control trial (1847 ± 286 mL min−1), and was similar in the two hyperventilation trials. These results suggest that 5 min of pre-exercise hypocapnic hyperventilation reduces aerobic metabolism during the 30-s WAnT to a level similar to that seen with the 20-min hyperventilation. Moreover, exercise performance was unaffected, which implies anaerobic metabolism was enhanced. [ABSTRACT FROM AUTHOR]

Introduction: Caffeine is an exercise performance enhancer widely used by individuals engaged in training or competition under heat-stressed conditions. Caffeine ingestion during exercise in the heat is believed to be safe because it does not greatly affect body temperature responses, heart rate, or body fluid status. However, it remains unknown whether caffeine affects hyperthermia-induced hyperventilation or reductions in the cerebral blood flow index. We tested the hypothesis that under conditions inducing severe hyperthermia, caffeine exacerbates hyperthermia-induced hyperventilation and reduces the cerebral blood flow index during exercise. Methods: Using a randomized, single-blind, crossover design, 12 physically active healthy young men (23 ± 2 yr) consumed a moderate dose of caffeine (5 mg·kg−1) or placebo in the heat (37°C). Approximately 60 min after the ingestion, they cycled for ~45 min at a workload equal to ~55% of their predetermined peak oxygen uptake (moderate intensity) until their core temperature increased to 2.0°C above its preexercise baseline level. Results: In both trials, ventilation increased and the cerebral blood flow index assessed by middle cerebral artery mean blood velocity decreased as core temperature rose during exercise (P < 0.05), indicating that hyperthermia-induced hyperventilation and lowering of the cerebral blood flow occurred. When core temperature was elevated by 1.5°C or more (P < 0.05), ventilation was higher and the cerebral blood flow was lower throughout the caffeine trial than the placebo trial (P < 0.05). Conclusions: A moderate dose of caffeine exacerbates hyperthermia-induced hyperventilation and reductions in the cerebral blood flow index during exercise in the heat with severe hyperthermia. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of voluntary hypocapnic hyperventilation or moderate hypoxia on metabolic and heart rate responses during high-intensity intermittent exercise.Methods: Ten males performed three 30-s bouts of high-intensity cycling [Ex1 and Ex2: constant-workload at 80% of the power output in the Wingate anaerobic test (WAnT), Ex3: WAnT] interspaced with 4-min recovery periods under normoxic (Control), hypocapnic or hypoxic (2500 m) conditions. Hypocapnia was developed through voluntary hyperventilation for 20 min prior to Ex1 and during each recovery period.Results: End-tidal CO2 pressure was lower before each exercise in the hypocapnia than control trials. Oxygen uptake ([Formula: see text]) was lower in the hypocapnia than control trials (822 ± 235 vs. 1645 ± 245 mL min-1; mean ± SD) during Ex1, but not Ex2 or Ex3, without a between-trial difference in the power output during the exercises. Heart rates (HRs) during Ex1 (127 ± 8 vs. 142 ± 10 beats min-1) and subsequent post-exercise recovery periods were lower in the hypocapnia than control trials, without differences during or after Ex2, except at 4 min into the second recovery period. [Formula: see text] did not differ between the control and hypoxia trials throughout.Conclusions: These results suggest that during three 30-s bouts of high-intensity intermittent cycling, (1) hypocapnia reduces the aerobic metabolic rate with a compensatory increase in the anaerobic metabolic rate during the first but not subsequent exercises; (2) HRs during the exercise and post-exercise recovery periods are lowered by hypocapnia, but this effect is diminished with repeated exercise bouts, and (3) moderate hypoxia (2500 m) does not affect the metabolic response during exercise. [ABSTRACT FROM AUTHOR]