Endurance Exercise in Hypoxia, Hyperoxia and Normoxia: Mitochondrial and Global Adaptations.

We hypothesized short-term endurance exercise (EN) in hypoxia (HY) to exert decreased mitochondrial adaptation, peak oxygen consumption (VO2peak) and peak power output (PPO) compared to EN in normoxia (NOR) and hyperoxia (PER). 11 male subjects performed repeated unipedal cycling EN in HY, PER, and NOR over 4 weeks in a cross-over design. VO2peak, PPO, rate of perceived exertion (RPE) and blood lactate (Bla) were determined pre- and post-intervention to assess physiological demands and adaptation. Skeletal muscle biopsies were collected to determine molecular mitochondrial signaling and adaptation. Despite reduced exercise intensity (P<0.05), increased Bla and RPE levels in HY revealed higher metabolic load compared to PER (P<0.05) and NOR (n.s.). PPO increased in all groups (P<0.05) while VO2peak and mitochondrial signaling were unchanged (P>0.05). Electron transport chain complexes tended to increase in all groups with the highest increase in HY (n.s.). EN-induced mitochondrial adaptability and exercise capacity neither decreased significantly in HY nor increased in PER compared to NOR. Despite decreased exercise intensity, short term EN under HY may not necessarily impair mitochondrial adaptation and exercise capacity while PER does not augment adaptation. HY might strengthen adaptive responses under circumstances when absolute training intensity has to be reduced.

Monitoring Training Load in Handcycling: A Case Study.

Zeller, S, Abel, T, and Strueder, HK. Monitoring training load in handcycling: a case study. J Strength Cond Res 31(11): 3094-3100, 2017-The aim of this study was to analyze the training intensity distribution (TID) and the total training load (TTL) for the first time in handcycling of a multiple female Paralympic medalist (lesion level: L2-3 incomplete, ASIA C, classification: WH5). This study focuses on the preparation and the competitive period of the 2015 season. The athlete completed 194 handcycling training sessions in a time of 433:53 hours, covering a total distance of 10.190 km. An average training week consisted of 9:38 ± 4:50 hours of training during 4.3 ± 1.5 training sessions. Training was categorized according to the 3-zone intensity scale (zone 1: below blood lactate levels of 2 mmol·L; zone 2: between 2 mmol·L and 4 mmol·L; and zone 3: above 4 mmol·L). The average TID during the observation was 71.6 ± 14.9% in zone 1, 15.2 ± 8.0% in zone 2, and 13.1 ± 5.5% in zone 3. The analysis of TID throughout the season demonstrates a tendency toward a greater volume in zone 2 than the recommendations in the literature. The mean TTL throughout the season was 804 ± 399 arbitrary units. During the investigation, the performance capacity in the incremental exercise test analog to 4 mmol·L increased by 19% (150-181 W), whereas the peak power output improved by 22% (180-200 W). Currently, no general guideline for the TTL and TID in paraplegic endurance athletes can be given.

Influence of noncircular chainring on male physiological parameters in hand cycling.

The purpose of this study was to examine the influence of a noncircular chainring (NCC) compared with a conventional circular chainring (CC) on hand cycling performance. Eleven nondisabled male participants with no hand cycling experience initially completed an incremental exercise test. Afterward, the participants completed two 20 s sprint tests, followed by a 20 min endurance test and then another two 20 s sprint tests. An NCC and a CC were used in random order on two separate occasions. To compare the effects of the NCC and CC on power data of the sprint tests and metabolic response during the endurance test, a two-way analysis of variance for repeated measures was used. Average power values of the sprint tests showed no significant difference between NCC and CC, but over time, values of the first and third sprint tests were higher than those of the second and fourth sprint tests for both chainrings. Values of energy expenditure (kilojoules), gross efficiency (percentage), and net efficiency (percentage) after 10 and 20 min during the endurance test using NCC and CC showed no significant differences (p > 0.05) either between tests or over time. Under the current test conditions and focusing on physiological parameters, a performance optimization using an NCC in hand cycling could not be proven.

Exercise in isolation--a countermeasure for electrocortical, mental and cognitive impairments.

INTRODUCTION: Mental impairments, including deterioration of mood and cognitive performance, are known to occur during isolation and space missions, but have been insufficiently investigated. Appropriate countermeasures are required, such as exercise, which is known to prevent mood disorders for prolonged space and isolation missions. Based on the interaction of brain activity, mood and cognitive performance, this study aims to investigate the effect of long-term isolation and confinement and the long-term effect of exercise on these parameters. METHODS: Eight male volunteers were isolated and confined for about eight month during the winter period at the Antarctic Concordia Station. Every six weeks electroencephalographic measurements were recorded under rest conditions, and cognitive tests and a mood questionnaire were executed. Based individual training logs, subjects were afterwards separated into an active (> 2500 arbitrary training units/interval) or inactive (< 2500 arbitrary training units/interval) group. RESULTS: A long-term effect of exercise was observed for brain activity and mood. Regularly active people showed a decreased brain activity (alpha and beta) in the course of isolation, and steady mood. Inactive people instead first increased and than remained at high brain activity accompanied with a deterioration of mood. No effect of exercise and isolation was found for cognitive performance. CONCLUSION: The findings point out the positive effect of regularly performed voluntary exercise, supporting subjective mental well-being of long-term isolated people. The choice to be regularly active seems to support mental health, which is not only of interest for future isolation and space missions.