Effects of Repeated-Sprint Training in Hypoxia on Tennis-Specific Performance in Well-Trained Players

Abstract

This study examined the physiological, physical and technical responses to repeated-sprint training in normobaric hypoxia [RSH, inspired fraction of oxygen (FiO 2 ) 14.5%] vs. normoxia (RSN, FiO 2 20.9%). Within 12 days, eighteen well-trained tennis players (RSH, n=9 vs. RSN, n=9) completed five specific repeated-sprint sessions that consisted of four sets of 5 maximal shuttle-run sprints. Testing sessions included repeated-sprint ability and Test to Exhaustion Specific to Tennis (TEST). TEST’s maximal duration to exhaustion and time to attain the ‘onset of blood lactate accumulation’ at 4 mMol.L −1 (OBLA) improvements were significantly higher in RSH compared to RSN. Change in time to attain OBLA was concomitant with observations similar in time to the second ventilatory threshold. Significant interaction (P=0.003) was found for ball accuracy with greater increase in RSH (+13.8%, P=0.013) vs. RSN (–4.6%, P=0.15). A correlation (r=0.59, P<0.001) was observed between change in ball accuracy and TEST’s time to exhaustion. Greater improvement in some tennis-specific physical and technical parameters was observed after only 5 sessions of RSH vs. RSN in well-trained tennis players.

On the Use of the Repeated-Sprint Training in Hypoxia in Tennis

“…A priori power analysis using G * Power software (version 3.1.9.3) was conducted to determine the appropriate sample size. Based on the data from a previous study (Brechbuhl et al, 2018a) on effects of repeated-sprints in hypoxia (∼3000 m) vs. normoxia, 27 participants overall were required to yield the targeted analysis power of β = 0.8 at α = 0.05 for three groups and three measurements. To reach the appropriate sample size with potential risks of drop-out or injuries, the present sample was increased to n = 36.…”

“…After 40 min of rest, subjects performed an incremental field test up to exhaustion [i.e., the so-called test to exhaustion specific to tennis (TEST)] as detailed previously (Brechbuhl et al, 2016a(Brechbuhl et al, , 2018a. Briefly, TEST consisted of hitting balls thrown by a "Hightof " R ball machine at constant velocity.…”

“…For example, single sprint time (−4.5%), RSA total time (−3.1%) and sprint decrement (−16.7%) improved in one rookie tennis player during a stress test 3 weeks after undertaking a RSH intervention (Brechbuhl et al, 2018b). Well-trained tennis players also increased time to exhaustion and onset of blood lactate accumulation at 4 mMol L −1 as well as the ball accuracy (+13.8%) immediately after five RSH sessions (Brechbuhl et al, 2018a).…”

“…It was proposed that the effectiveness of RSH comes from an improved muscle blood perfusion, which in turn would benefit from optimized oxygen extraction by fast-twitch fibers (Faiss et al, 2013b). Since a previous study (Brechbuhl et al, 2018a) has reported that RSH can maintain a high level of accuracy at high levels of playing intensity, it would be of interest to investigate if cerebral as well as muscular blood flow could be increased using near infrared spectroscopy (NIRS).…”

High-Intensity Exercise With Blood Flow Restriction or in Hypoxia as Valuable Spaceflight Countermeasures?

“…Additionally, the increased changes in blood perfusion due to the combination of high-intensity and hypoxic stress may be a stimulus for altering vascular blood flow regulation due to neural, metabolic, and mechanical influences. Of interest is that short blocks (i.e., as little as 4–8 repeated sprint training sessions in hypoxia), led to improved performance for elite athletes in different sports as cycling (Faiss et al, 2013), cross-country skiing (Faiss et al, 2014), rugby (Beard et al, 2018, 2019), and tennis (Brechbuhl et al, 2018). To our knowledge, there is no data available on the effects of such exercises in astronauts and other participants during spaceflights but one may speculate that performing high-intensity exercise training in hypoxia may be a valuable and practical method for exercise countermeasure during spaceflight missions.…”