. Rhodiola crenulata-and Cordyceps sinensis-based supplement boosts aerobic exercise performance after short-term high altitude training. High Alt Med Biol 15:371-379, 2014.-High altitude training is a widely used strategy for improving aerobic exercise performance. Both Rhodiola crenulata (R) and Cordyceps sinensis (C) supplements have been reported to improve exercise performance. However, it is not clear whether the provision of R and C during high altitude training could further enhance aerobic endurance capacity. In this study, we examined the effect of R and C based supplementation on aerobic exercise capacity following 2-week high altitude training. Alterations to autonomic nervous system activity, circulatory hormonal, and hematological profiles were investigated. Eighteen male subjects were divided into two groups: Placebo (n = 9) and R/C supplementation (RC, n = 9). Both groups received either RC (R: 1400 mg + C: 600 mg per day) or the placebo during a 2-week training period at an altitude of 2200 m. After 2 weeks of altitude training, compared with Placebo group, the exhaustive run time was markedly longer (Placebo: + 2.2% vs. RC: + 5.7%; p < 0.05) and the decline of parasympathetic (PNS) activity was significantly prevented in RC group (Placebo: -51% vs. RC: -41%; p < 0.05). Red blood cell, hematocrit, and hemoglobin levels were elevated in both groups to a comparable extent after high altitude training ( p < 0.05), whereas the erythropoietin (EPO) level remained higher in the Placebo group (*48% above RC values; p < 0.05). The provision of an RC supplement during altitude training provides greater training benefits in improving aerobic performance. This beneficial effect of RC treatment may result from better maintenance of PNS activity and accelerated physiological adaptations during high altitude training.
In the present study, we investigated the effect of a long-term mountain expedition on glucose tolerance and insulin action. Twelve registered mountaineers ages 31 years (SD = 1.1) participated in a 25-day expedition at a 2,200-3,800-m altitude with an average duration of 8 hr per day. Arterial oxygen saturation (SaO2) was substantially reduced during hiking. Glucose tolerance and insulin responses were measured prior to and twice during the expedition period. Maximal oxygen consumption increased from 43.0 +/- 2.7 to 49.1 +/- 2.2 mL/kg/min. Percentage of body fat decreased from 19.4 +/- 6.8% to 16.9 +/- 5.9%. The area under the curves for insulin and glucose during the oral glucose tolerance test were also reduced in Days 3 and 25. The present study demonstrated that altitude hiking activity is an effective lifestyle intervention to improve insulin action.
In the pole vault event, the velocity of approach is a highly vital factor. As velocity of approach improvements highly impact performance improvements. This study analysed the relationships between sprint running's speed (SR), pole running (PR, without jump), and the pole vault approach (PVA, with real jump). Analysed too were the relationships between both the approach and performance's respective running distance, velocity, and velocity utilization rates. Methods: Ten male pole vaulters were recruited. Measured was each 5-meter segment's average velocity of his respective SR, PR, and PVA, along with the distance to maximum velocity. Results: The maximum average velocity of the PR's 5m segments altogether was significantly positively correlated with pole vault (PV) performance; The maximum average velocity of the PR's 5m segments altogether was significantly positively correlated with the last 5m PVA average velocity; The PVA velocity's utilization rate was significantly negatively correlated with the difference between the distance to the PR's maximum velocity and the PVA's distance. Conclusion: The PR segment's maximum speed capability can evaluate both a pole vaulter's potential and pole vault-specific abilities. This study's recruited pole vaulters' respective approach distances were generally insufficient that resulted in a lower velocity utilization rate. Suggested is that in training, the pole vaulter could first find the distance required to reach the highest velocity upon starting from the PR test. Thus, this subsequently known distance could be applied in tandem with the pole vault's approach to both improve the PVA's utilization rate and reach the individual highest speed level.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.