The effects of two weeks low-volume self-regulated high-intensity interval training on cardiorespiratory fitness, exercise enjoyment, and intentions to repeat

Abstract

This study investigated the effect of low-volume self-regulated high-intensity interval training (SR-HIIT) on cardiorespiratory fitness (CRF), exercise enjoyment, and intentions to repeat. Ten untrained, physically active adults (five males and five females, age: 20.3 ± 0.5 years) undertook a 2-week control period followed by 2-weeks SR-HIIT (6 x 10 min cycle ergometer sessions). Sessions involved alternate bouts at a rating of perceived exertion of 17 (work) and 11 (recovery), with bout durations self-regulated by the participant. Maximal aerobic capacity showed a small increase from post-control (3.14 ± 1.03 L.min-1) to post-training (3.45 ± 1.14 L.min-1; diff 0.31, 95%CI 0.06 L.min-1, d = 0.28, 95%CL 0.11, 0.45). First ventilatory threshold showed a large increase from post-control (65.6 ± 2.1% V̇O2max) to post-training (68.0 ± 2.4% V̇O2max; diff 2.4, 95%CI 1.2%, d = 0.96, 95%CL 0.27, 1.62). Post-exercise enjoyment showed small ( diff 3.5, 95%CI 8.1 AU, d = 0.31) and medium ( diff 6.9, 95%CI 6.7 AU, d = 0.68) increases from SR-HIIT session 1-3 and 3-6, respectively. There were trivial to medium increases in intention to repeat SR-HIIT once per week (d = 0.06 to 0.63) and three times per week (d = 0.28 to 0.60). Low-volume SR-HIIT elicits meaningful improvements in CRF, is enjoyable, and facilitates good intentions to repeat, and may be an additional option for implementing HIIT to improve general population health and fitness.

Keywords

• sports health
• intermittent
• perception
• aerobic