Low-frequency High-Intensity Interval Training in Overweight or Obese Young Adults

HIIT groups performed 30-meter shuttle runs on a rooftop covered field whereas MICT group ran on a footpath with an overall flat and non-slippery road surface. All training sessions were preceded by a 5-minute self-pace warm-up jogging and ended with a 5-minute self-pace jogging or walking cool-down. Each session of MICT consisted of 30 minutes of continuous exercise at an intensity of 60% of heart rate reserve (HRR); \[i.e., (maximal HR - resting HR) × intensity + resting HR\]. For each HIIT session, the intensity was set at 90% HRR for high-intensity bouts, interspersed with active recovery at 70% HRR. All exercise sessions were supervised by qualified athletic coach or strength and conditioning coach.