Fast Start Strategy in High-Intensity Interval Training in Rugby Union Academy Players

Area of Science:

• Exercise Physiology
• Sports Science
• High-Intensity Interval Training (HIIT)

Background:

• Fast-start strategy (HIIT-FS) optimizes oxygen uptake in endurance athletes.
• Effects of HIIT-FS on team sport athletes remain largely unexplored.
• Rugby union players require effective training to enhance aerobic capacity.

Purpose of the Study:

• To compare physiological, perceptual, and external load responses between HIIT-FS and constant-intensity HIIT (HIIT-C) in academy rugby players.
• To determine if HIIT-FS can enhance time spent at high oxygen uptake levels in team sport athletes.

Main Methods:

• Eight male rugby players performed a 30-15 Intermittent Fitness Test (IFT) to establish velocities.
• Participants completed both HIIT-FS and HIIT-C protocols.
• Measures included gas exchange (V̇O2peak, V̇O2mean), heart rate (HRpeak), ventilation (V̇Emean), respiratory frequency (fRmean), GPS-derived external load, and Rate of Perceived Exertion (RPE).

Main Results:

• HIIT-FS significantly increased time spent at ≥90% V̇O2peak (318.8s vs. 230.6s) and mean %V̇O2peak (86.1% vs. 82.1%) compared to HIIT-C.
• No significant differences in external load metrics (e.g., total distance, sprint distances) were observed between protocols.
• HIIT-FS resulted in significantly higher RPE (9.0 vs. 7.8) and greater time at ≥90% HRpeak during early intervals.

Conclusions:

• HIIT-FS effectively increases time at high oxygen uptake levels in rugby players without increasing external load.
• HIIT-FS is a promising strategy for improving aerobic capacity in team sport athletes.
• Due to higher perceived exertion, HIIT-FS may be best suited for shorter sessions or when limited training volume is possible.