Simple Bodyweight Training Improves Cardiorespiratory Fitness with Minimal Time Commitment: A Contemporary Application of the 5BX Approach.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 34055156 · doi:10.70252/WEQD2681
What was done
Nineteen healthy, inactive young adults (mean age 20 ± 1 years, BMI 20 ± 5 kg/m²) were randomized to either a 6-week bodyweight training program (n = 9; 18 sessions total) or a non-training control group (n = 10). The training protocol was an 11-minute session based on the 5BX plan consisting of five 60-second bodyweight exercises (burpees, high knees, split squat jumps, high knees, squat jumps) at a self-selected challenging pace, interspersed with active walking recovery periods. Cardiorespiratory fitness (VO2peak), peak power output, leg muscular endurance, handgrip strength, and vertical jump height were assessed before and after the intervention.
What was found
Participants completed 100% of the training sessions at an average intensity of 82 ± 5% of maximal heart rate and a rating of perceived exertion of 14 ± 3 on a 20-point scale. After 6 weeks, ANCOVA showed VO2peak was significantly higher in the training group compared to controls (34.2 ± 6.4 vs 30.3 ± 11.1 ml/kg/min, p = 0.03). Peak power output was also significantly higher in the training group (211 ± 43 vs 191 ± 50 W, p = 0.004). Neither group showed significant changes in leg muscular endurance, handgrip strength, or vertical jump height.
Why it matters
This demonstrates that an 11-minute bodyweight interval routine requiring no specialized equipment can meaningfully improve cardiorespiratory fitness in sedentary individuals with minimal time investment.
Limits
The sample size was very small (total n = 19; only 9 in the training arm), and the cohort was restricted to young, healthy inactive college-aged adults, limiting generalizability to older or clinical populations. The intervention duration was short (6 weeks), and longer-term adherence and health outcomes were not evaluated.
Cited by
- supports Performing bodyweight interval training such as air squats, burpees, and push-ups with short rests for 10 to 20 minutes can sustain heart rates at approximately 80% of maximum.