AUTHOR=Brechbuhl Cyril , Brocherie Franck , Willis Sarah J. , Blokker Thomas , Montalvan Bernard , Girard Olivier , Millet Gregoire P. , Schmitt Laurent 

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

JOURNAL=Frontiers in Physiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2020.588821

DOI=10.3389/fphys.2020.588821

ISSN=1664-042X

ABSTRACT=<sec><title>Purpose</title><p>To examine physiological and technical responses to repeated-sprint training in normobaric hypoxia at ∼3,000 m (RSH, <italic>n</italic> = 11) or in normoxia (RSN, <italic>n</italic> = 11) compared to a control group (CON, <italic>n</italic> = 8) in well-trained tennis players. Participants were 28.8 ± 5.9 years old without any previous experience of training in hypoxia.</p></sec><sec><title>Methods</title><p>In addition to maintaining their usual training (CON), both RSH and RSN groups completed five tennis specific repeated-shuttle sprint sessions (4 × 5 × ∼8 s maximal sprints with ∼22 s passive recovery and ∼5 min rest between sets) over 12 days. Before (Pre), the week after (Post-1) and 3 weeks after Post-1 (Post-2), physical/technical performance during Test to Exhaustion Specific to Tennis (TEST), repeated-sprint ability (RSA) (8 × ∼20 m shuttle runs—departing every 20 s) and heart rate variability (HRV) were assessed.</p></sec><sec><title>Results</title><p>From Pre to Post-1 and Post-2, RSH improved TEST time to exhaustion (+18.2 and +17.3%; both <italic>P</italic> &lt; 0.001), while the “onset of blood lactate accumulation” at 4 mmol L<sup>–1</sup> occurred at later stages (+24.4 and +19.8%, both <italic>P</italic> &lt; 0.01). At the same time points, ball accuracy at 100% V̇O<sub>2m</sub><sub>ax</sub> increased in RSH only (+38.2%, <italic>P</italic> = 0.003 and +40.9%, <italic>P</italic> = 0.007). Markers of TEST performance did not change for both RSN and CON. Compared to Pre, RSA total time increased significantly at Post-1 and Post-2 (−1.9 and −2.5%, <italic>P</italic> &lt; 0.05) in RSH only and this was accompanied by larger absolute Δ total hemoglobin (+82.5 and +137%, both <italic>P</italic> &lt; 0.001). HRV did not change either supine or standing positions.</p></sec><sec><title>Conclusion</title><p>Five repeated sprint training sessions in hypoxia using tennis specific shuttle runs improve physiological and technical responses to TEST, RSA, and accompanying muscle perfusion responses in well-trained tennis players.</p></sec>