What is the clinical evidence from this study?

Study design: RCT. Population: Well-trained male rugby players (n=19). Intervention: Hypoxic repeat sprint training (FIO2 = 14.5%) vs. Normobaric normoxia (FIO2 = 20.9%). Primary outcome: Repeated sprint fatigue at Post-test 3 (change from baseline).

February 6, 2017Open Access

Hypoxic Repeat Sprint Training Improves Rugby Player's Repeated Sprint but Not Endurance Performance

Key Result

Six sessions of repeat-sprint training in hypoxia improved repeat sprint ability but not endurance performance in well-trained male rugby players compared to normoxic training.

Study Design

Type

RCT (n=19)

Blinding

Single-blind

Randomization

Randomized

Multicenter

Structured PICO

Does repeat-sprint training in normobaric hypoxia improve repeated sprint and endurance performance in well-trained male rugby players?

Population

19 well-trained male rugby players (representative and club players) from Canterbury, New Zealand.

Intervention

Repeat-sprint training (six sessions of four sets of 5 x 5 s sprints with 25 s and 5 min of active recovery between reps and sets respectively) in normobaric hypoxia (FIO2 = 14.5%), plus 2 additional 'top-up' sessions.

Comparator

Matching repeat-sprint training in normobaric normoxia (FIO2 = 20.9%).

Outcome

Repeated sprint performance (8 x 20m) and Yo-Yo Intermittent Recovery Level 1 (YYIR1) performance.surrogate

Repeat-sprint training in hypoxia for 6 sessions increases repeat sprint ability but not endurance performance in well-trained rugby players.

Main Result

Absolute Event Rate: -2.3% vs -0.3%

Limitations

Higher training stress (heart rate and perceived exertion) in the hypoxic group makes it difficult to attribute benefits solely to hypoxia rather than harder training load.
Participants were well-trained amateur rugby players, so results may not reflect elite players.
Field study design increased the risk of extraneous variables, such as a pre-season game played prior to the last testing day.

Abstract

This study aims to investigate the performance changes in 19 well-trained male rugby players after repeat-sprint training (six sessions of four sets of 5 x 5 s sprints with 25 s and 5 min of active recovery between reps and sets respectively) in either normobaric hypoxia (HYP; n = 9; FIO2 = 14.5%) or normobaric normoxia (NORM; n = 10; FIO2 = 20.9%). Three weeks after the intervention, 2 additional repeat-sprint training sessions in hypoxia (FIO2 = 14.5%) was investigated in both groups to gauge the efficacy of using ‘top-up’ sessions for previously hypoxic-trained subjects and whether a small hypoxic dose would be beneficial for the previously normoxic-trained group. Repeated sprint (8 x 20m) and Yo-Yo Intermittent Recovery Level 1 (YYIR1) performances were tested twice at baseline (Pre 1 and Pre 2) and weekly after (Post 1-3) the initial intervention (intervention 1) and again weekly after the second ‘top-up’ intervention (Post 4-5). After each training set, heart rate, oxygen saturation and rate of perceived exertion were recorded. Compared to baseline (mean of Pre 1 and Pre 2), both the hypoxic and normoxic groups similarly lowered fatigue over the 8 sprints one week after the intervention (Post 1: -1.8 ± 1.6%, -1.5 ± 1.4%, mean change ± 90% CI in HYP and NORM groups respectively). However, from Post 2 onwards, only the hypoxic group maintained the performance improvement compared to baseline (Post 2: -2.1 ± 1.8%, Post 3: -2.3 ± 1.7%, Post 4: -1.9 ± 1.8%, and Post 5: -1.2 ± 1.7%). Compared to the normoxic group, the hypoxic group was likely to have substantially less fatigue at Post 3-5 (-2.0 ± 2.4%, -2.2 ± 2.4%, -1.6 ± 2.4% Post 3, Post 4, Post 5 respectively). YYIR1 performances improved throughout the recovery period in both groups (13-37% compared to baseline) with unclear differences found between groups. The addition of two sessions of ‘top-up’ training after intervention 1, had little effect on either group. Repeat-sprint training in hypoxia for 6 sessions increases repeat sprint ability but not YYIR1 performance in well-trained rugby players.

Bookmark

View Full Paper