Is high-intensity interval training the best way to improve aerobic exercise performance?

    Written by:
    Kamal Patel
    Last Updated: May 16, 2025

    A combination of high-intensity interval training (HIIT) and exercise at low to moderate intensity is likely the most effective approach to improve aerobic exercise performance because it enhances aerobic capacity more than moderate-intensity training alone. Although HIIT can improve VO2max with a lower time commitment, longer intervals and workouts that exceed 15 minutes are recommended for optimal results.

    A combination of HIIT and low- to moderate-intensity exercise training — which elite athletes use — is likely the best way to improve aerobic exercise performance. Research shows that combining HIIT with moderate-intensity training is more effective for improving aerobic capacity than moderate-intensity training alone.[1] However, when workouts are matched for energy expenditure, HIIT may improve VO2max by an additional 1.2–3.3 mL/kg/min versus moderate-intensity training,[2][3] despite requiring an approximately 2- to 3-fold lower time commitment.[4]

    Lower-volume HIIT — also known as sprint-interval training (SIT) — consisting of maximal effort 30-second sprints is shown to improve running economy and 10-kilometer time trial performance in runners.[5] However, longer intervals (2–4 minutes) may be more effective for improving VO2max compared to shorter intervals (10–30 seconds). Additionally, for HIIT to be most effective at improving VO2max, the ideal workout duration should be greater than 15 minutes.[3]