The effects of different work: Rest durations on physiological, neuromuscular, and ratings of perceived exertion responses during taekwondo-specific high-intensity interval training

Abstract

Purpose: To investigate the effect of different work: rest durations on physiological, neuromuscular, and perceived exertion responses during taekwondo-specific high-intensity interval training (HIIT).

Methods: Thirteen moderate-trained taekwondo athletes (age: 21.7 ± 2.4 years; body mass: 69.1 ± 7.6kg; height: 174 ± 6 cm) completed a familiarization session and three HIIT trials. The trial consisted of three rounds of 2 min roundhouse kicks with 1 min of rest in between. In each round, the work: rest ratio was constant at 1:2, and the work: rest duration varied to be: short (2s:4s), medium (10s:20s), and long (20s:40s). Heart rate (HR) and oxygen uptake ( $\dot{V}$ O₂) were continuously measured. Blood lactate concentration ([La^-]), countermovement jump (CMJ), and rating of perceived exertion (RPE) were recorded before trials and after each round. Energy contribution was estimated.

Results: HR, $\dot{V}$ O_2, and CMJ were similar across protocols (P > .05) but, [La^-] was higher during long than short work: rest duration protocol (P < .05). Relative aerobic energy contribution and RPE in round 3 were higher during long than short work: rest duration protocol (P < .05). Absolute and relative glycolytic energy contribution in rounds 1 and 2 were higher during long than short work: rest duration protocol (P < .05). Relative phosphate energy contribution in rounds 1 and 3 was lower during long than short work: rest duration protocol (P < .05).

Conclusion: Different work: rest durations of taekwondo-specific HIIT influenced [La^-], energy system contributions, and RPE. The longer work: rest duration protocol (20s:40s) stressed more the glycolytic, aerobic energy systems and perceived exertion, and less the phosphagen energy system.

Keywords: Combat sport; Energy systems; Heart rate; Oxygen uptake; Work: rest duration.

Fig. 1

Experimental protocol.

Fig. 2

Changes in percentage of energy contribution across three trials. Note: W_aer = aerobic energy; W_pcr = anaerobic alactic energy; W_[La⁻_] = anaerobic lactic energy; 2s:4s = short work: rest duration protocol; 10s:20s = medium work: rest duration protocol; 20s:40s = long work: rest duration protocol. ^aP < .05 = significantly different from round 1; ^bP < .05 = significantly different from round 2; ∗P < .05 = significantly different from the short work: rest duration protocol. ^#P < .05 = significantly different from the medium work: rest duration protocol.