The purpose of this study was to compare peak cardiorespiratory, metabolic and perceptual responses to acute bouts of Sprint Interval Cycling (SIC) and a High-intensity Intermittent Calisthenics (HIC) protocol consisting of modified "burpees". Eleven (8 men and 3 women) moderately-trained, college-aged participants (age = 21.9 +/- 2.1, BMI = 24.8 +/- 1.9, VO2peak = 54.1 +/- 5.4 mL[BULLET OPERATOR]kg-1[BULLET OPERATOR]min-1) completed four testing sessions across nine days with each session separated by 48-72 hours. Using a protocol of four repeated bouts of 30-s "all out" efforts interspersed with 4-min active recovery periods, responses to SIC and HIC were classified relative to peak values. Mean values for %VO2peak and %HRpeak for SIC (80.4 +/- 5.3% and 86.8 +/- 3.9%) and HIC (77.6 +/- 6.9% and 84.6 +/- 5.3%) were not significantly different (p > 0.05). Effect sizes (95% confidence interval) calculated for mean differences were: %VO2peak Cohen's d = 0.51 (0.48, 0.53; %HRpeak Cohen's d = 0.57 (0.55, 0.59). A low-volume, high-intensity bout of repeated whole-body calisthenic exercise induced cardiovascular responses that were not significantly different but were ~1/2 standard deviation lower than "all-out" SIC. These results suggest that in addition to the benefit of reduced time commitment, a high-intensity interval protocol of calisthenics elicits vigorous cardiorespiratory and perceptual responses and may confer physiological adaptations and performance improvements similar to those reported for SIC. The potential efficacy of this alternative interval training method provides support for its application by athletes, coaches and strength and conditioning professionals.
Alex’s notes: Sprint! We have all heard it. Sprinting and other modes of high-intensity interval training (HIIT) are commonly used forms of training in both elite athletes and average Joes. Surprisingly, no study to date has looked at bodyweight HIIT. The purpose of the study at hand was to compare the physiologic responses of repeated sprints on a cycle ergometer to those of… burpees.
The participants were eleven college-aged ROTC members that engaged in a year-long(!) resistance training routine before this study was conducted to create a baseline fitness level. During this study, the participants performed four testing sessions at the same time of day across nine days with 48-72 hours of rest between each session. This helped eliminate confounding variables such as training differences and circadian hormonal changes. The sessions were 4 bouts of 30 seconds all-out exertion (cycling as fast as possible against resistance equating 7.5% their bodyweight, or doing as many burpees as possible) followed by 4 minutes of active recovery.
Sprints won, but barely. The cardiorespiratory responses were greater in the cycling than the calisthenics by about 2% and these differences didn’t even reach statistical significance. Moreover, the burpees had a lower rating of perceived exertion, which did reach statistical significance. In other words, HIIT burpees may confer cardiorespiratory and metabolic adaptations similar to sprints but with less perceived effort. Oh, and unlike sprints that require specialized equipment or a running protocol with enough open space, burpees are cost-free and can be performed anywhere with minimal space.
Now if you prefer to use equipment and don’t like burpees, Dan John has some great complexes that will give you a run for your money. Do a couple circuits of 5-8 repetitions per exercise and tell me they aren’t hard.