Repeated sprint training in normobaric hypoxia

Abstract

Repeated sprint ability (RSA) is a critical success factor for intermittent sport performance. Repeated sprint training has been shown to improve RSA, we hypothesised that hypoxia would augment these training adaptations. Thirty male well-trained academy rugby union and rugby league players (18.4±1.5 years, 1.83±0.07 m, 88.1±8.9 kg) participated in this single-blind repeated sprint training study. Participants completed 12 sessions of repeated sprint training (10×6 s, 30 s recovery) over 4 weeks in either hypoxia (13% FiO2) or normoxia (21% FiO2). Pretraining and post-training, participants completed sports specific endurance and sprint field tests and a 10×6 s RSA test on a non-motorised treadmill while measuring speed, heart rate, capillary blood lactate, muscle and cerebral deoxygenation and respiratory measures. Yo-Yo Intermittent Recovery Level 1 test performance improved after RS training in both groups, but gains were significantly greater in the hypoxic (33±12%) than the normoxic group (14±10%, p<0.05). During the 10×6 s RS test there was a tendency for greater increases in oxygen consumption in the hypoxic group (hypoxic 6.9±9%, normoxic (−0.3±8.8%, p=0.06) and reductions in cerebral deoxygenation (% changes for both groups, p=0.09) after hypoxic than normoxic training. Twelve RS training sessions in hypoxia resulted in twofold greater improvements in capacity to perform repeated aerobic high intensity workout than an equivalent normoxic training. Performance gains are evident in the short term (4 weeks), a period similar to a preseason training block.

No Improved Performance With Repeated-Sprint Training in Hypoxia Versus Normoxia: A Double-Blind and Crossover Study

“…In this regard, the proposed effect of RSH on RS performance was observed without prior exercise and in normoxic conditions [2][3][4][5] . Whether such effect can be extrapolated to situations including prior exhaustive exercise (such as at the end of a XC-ski or bicycle race) and hypoxic conditions remains uncertain; if confirmed, RSH could be of major relevance for athletic competitions critically determined in fatiguing conditions and/or carried out at altitude 7 .…”

“…If applying the criterion for exhaustion used herein (<70 % of the best (peak) sprint power output), the number of repeated sprints accomplished would be apparently similar following RSH vs. RSN in the above studies, which either did not use any criterion 3 or did apply the <70 % power criterion but not related to the actual best sprint power output 4 . Nevertheless, a single-blind study evaluating the effects of RSH has reported an increase in the distance covered in the Yo-Yo intermittent recovery test after 4 weeks of training in well trained rugby players 5 . Taken together, RSH does not seem to improve RS ability with regard to RSN when both a rigorous criterion for exhaustion/task failure and a double-blind design are applied.…”

“…Indeed, previous studies have reported increased estimates of blood perfusion but unchanged activation of skeletal muscle during RS tests along with improvements in RS performance following RSH 3,4 . In particular, the number of repeated cycling and cross-country skiing double-poling sprints to exhaustion 3,4 and distance covered in the Yo-Yo intermittent recovery test 5 were further increased after 2-4 weeks of RSH vs. the same training under normoxic conditions (RSN) in moderately to highly endurance 3,4 and strength 5 trained young subjects. However, the aforementioned studies present important limitations such as lack of double-blind design 3,5 or controversial/absent criteria for exhaustion in the RS test 3,4 .…”

Hypoventilation Training at Supramaximal Intensity Improves Swimming Performance

“…It is important to note that the subjects were never asked to perform the 25 m at maximal velocity. The feature of the present study was therefore distinguishable from that of the RSH studies (11,13).…”

“…The majority of the controlled studies that reported advantageous effects used exercise intensities equal to or higher than the second ventilatory threshold (8,31). Furthermore, some remarkable effects have been highlighted these last 2 yr after training with repeated sprint (i.e., short all-out exertions) in hypoxia (RSH) (11,13), which could be considered as a superior form of IHT. Thus, one could assume that such results could be reproduced through VHL training at high intensity, especially because the intermittent hypercapnic effect may play an additional role in the physiological adaptations leading to improved performance.…”