PMID 40689309

Research
All papers

Real-world efficacy of equipment-free reduced-exertion high-intensity interval training in improving physical and mental health in inactive males: A randomized controlled trial

Hu M, Chen X, Nie J, Shi Q, Kong Z

Question

Can equipment-free reduced-exertion HIIT, delivered either supervised or in a real-world self-managed format, improve physical and mental health in inactive men compared with cycling SIT and no exercise?

Summary

In inactive young men, a 12-week program of very brief burpee-style intervals improved body mass, VO2max, blood pressure, and several mental-health questionnaire measures compared with no exercise. A real-world unsupervised version produced smaller VO2max gains than supervised burpees but better affect/enjoyment and no reported adverse events. The evidence is highly relevant to equipment-free HIIT, but only in young men and with short-term follow-up.

Methodology

  • Inactive healthy young men.
  • 319 participants.
  • Equipment-free burpee-jump intervals.
  • Work intervals: 20 s all-out.
  • Recovery: 10 s passive recovery.
  • Intensity: All-out; >85% HRmax and RPE >8 thresholds for real-world sessions.
  • About 2 min including 1-min warm-up.
  • 3-5 sessions/week.
  • 12 weeks.
  • Four-arm randomized controlled trial.
  • VO2max, Body mass and blood pressure, Mental health and affect, and Sleep were tracked.

Outcomes

VO2max

All exercise groups improved VO2max; supervised BIT matched SIT and BIT-RW improved less but still improved versus control.

Exercise groups +8-13%; supervised BIT and SIT +5.0 +/- 0.6 mL/kg/min; BIT-RW +3.0 +/- 0.6 mL/kg/min.

Improved

Body mass and blood pressure

Exercise groups reduced body mass/BMI and blood pressure compared with control.

Body mass reductions about 6-8%, p < .001.

Improved

Mental health and affect

Stress, anxiety, depression, resilience, and quality of life improved; BIT-RW had the most favorable affect/enjoyment.

Reported stress -49-61%, anxiety -37-86%, depression -14-48%, resilience +22-27%, QoL +14-27%.

Improved

Sleep

Sleep did not improve significantly by group.

Sleep group effect p = .380; change group effect p = .537.

No clear change

Insights

  • A 2-min bodyweight HIIT format is highly app-translatable.
  • Real-world delivery may improve enjoyment while slightly reducing fitness gains.
  • Burpee protocols need lower-impact options and soreness expectations.

Limitations

  • Inactive young male sample only.
  • No long-term follow-up.
  • No detailed body composition imaging or strength outcomes.
  • Healthy baseline mental health limits mental-health generalization.
  • No direct energy expenditure, appetite, or hormone data.

Safety

  • BIT-RW had no adverse events.
  • Supervised BIT caused upper-body and thigh soreness, especially in the first 2 weeks.
  • SIT caused four nausea/vomiting events immediately after sessions in weeks 1-4.
  • All events were mild-moderate, transient, and resolved without medical intervention.