Prolonged Sojourn at Very High Altitude Decreases Sea-Level Anaerobic Performance, Anaerobic Threshold, and Fat Mass

Background: The influence of high altitude on an organism’s physiology depends on the length and the level of hypoxic exposure it experiences. This study aimed to determine the effect of a prolonged sojourn at very high altitudes (above 3,500m) on subsequent sea-level physical performance, body weight, body composition, and hematological parameters.Materials and Methods: Ten alpinists, nine males and one female, with a mean age of 27±4years, participated in the study. All had been on mountaineering expeditions to 7,000m peaks, where they spent 30±1days above 3,500m with their average sojourn at 4,900±60m. Their aerobic and anaerobic performance, body weight, body composition, and hematological parameters were examined at an altitude of 100m within 7days before the expeditions and 7days after they descended below 3,500m.Results: We found a significant (p<0.01) decrease in maximal anaerobic power (MAPWAnT) from 9.9±1.3 to 9.2±1.3W·kg−1, total anaerobic work from 248.1±23.8 to 228.1±20.1J·kg−1, anaerobic threshold from 39.3±8.0 to 27.8±5.6 mlO2·kg−1·min−1, body fat mass from 14.0±3.1 to 11.5±3.3%, and a significant increase (p<0.05) in maximal tidal volume from 3.2 [3.0–3.2] to 3.5 [3.3–3.9] L after their sojourn at very high attitude. We found no significant changes in maximal aerobic power, maximal oxygen uptake, body weight, fat-free mass, total body water, hemoglobin, and hematocrit.Conclusion: A month-long exposure to very high altitude led to impaired sea-level anaerobic performance and anaerobic threshold, increased maximal tidal volume, and depleted body fat mass, but had no effect on maximal aerobic power, maximal oxygen uptake, or hemoglobin and hematocrit levels.

Does Post-Activation Potentiation Protocols affect Anaerobic Performance in women Taolu Wushu Athletes?

Introduction: Post-activation potentiation has an influence on short duration and high intensity function. This study aimed to answer this question whether post-activation potentiation protocol in different models has effect on anaerobic performance in women Wushu athletes. Methods: Women elite Taolu Wushu athletes participated in current crossover design study. (i) specific Wushu WU (Wushu WU); (ii) Strength-based WU (StreWU); and (iii) Speed-based WU (SpeWU) were performed by Wushu athletes in three inconsecutive days separated by 48 h. Five minutes after each WU protocols, Running-Based Anaerobic Sprint Test (RAST) was performed. Heart rate, immediately, and blood lactate were measured for 4 times: before WU protocols, immediately after WU protocols, before RAST, immediately after RAST.Results: Data analysis revealed significant differences in 4 time points of lactate levels (p=0.001; d=1.71), although no significant difference among protocols was observed. Values of variables obtained from RAST showed that StreWU had a significant impact on minimum power (p<0.05; d=-0.795) comparing to WushuWU and on fatigue index comparing to SpeWU (p<0.05; d=-0.799). No significant differences were found among the WU protocols for peak power and mean power.Conclusion: All WU protocols had mostly the same effect, and PAP was not very effective. Possibly, the WU protocols generated too much fatigue, due to the short-term rest time. However, longer intervals would likely enter the realm of post-activation performance enhancement, which is distinct from PAP.

Effect of the use of the mouthguardon anaerobic performance: a systematic review

The prevention of trauma is important not only because of the expressive and growing prevalence of this injury, but also because of the high impact on quality of life in terms of physical, psychological and social discomfort, negatively interfering in the athlete's life and career. The use of mouthguards (PB) is an important intraoral device used by athletes, especially those with high performance, with the objective of preventing dental and facial trauma during sports practice. In addition, some studies point to the advantage of using (BP) related to occlusal stability and muscle synergism that can influence muscle strength gain. However, some athletes still resist using it because they believe it can negatively influence their performance. The aim of this study was to analyze the acute effect of the use of mouthguards on muscle strength performance through a systematic review. An extensive article searchwas performed, with only articles published before May 2021, using PubMed, Scopus, Web of Science, Latin American, and Caribbean Health Science Literature (LILACS) databases. 12 studies were selected for this systematic review. Five of the selected articles revealed that the use of mouthguard had significant beneficial effects on anaerobic performance tests, six showed no significant difference and only one had a negative impact. It is concluded that the present study supports and defends the use of mouthguards in athletes so that their performance is not affected.

Time-of-Day Effects on Anaerobic Power and Concentration of Selected Hormones in Blind Men

Knowledge of the circadian rhythm of the blind person and diurnal changes in anaerobic power and hormones concentration can create the possibility of individualising physical training. The aim of the study was to examine the time-of-day effects on anaerobic performance and the concentration of selected hormones. The measurements were performed at two different times of the day (10:00 a.m., 10:00 p.m.) in blind men at the age of 20–25 years old. The experiment group was chosen by using repeated hormonal tests four times a day so that each selected patient had a sleep/wake cycle even of 24 h. Anaerobic peak power and total work were tested in an anaerobic sprint test, and the concentration of growth hormone, testosterone, cortisol, and melatonin was determined. In blind men, the hormonal response was not driven by the photoperiod as in the control group. In the blind group, at 10:00 p.m., anaerobic peak power and total work results were significantly higher than at 10:00 a.m. and negatively correlated with melatonin levels. No such correlation was found in the control group.