High intensity interval training (HIIT) improves cardiorespiratory fitness, glycemic control, and body composition, yet the majority of studies used cycling which employs a smaller muscle mass. Less data have examined the acute response to whole-body HIIT. PURPOSE: To compare physiological responses between HIIT rowing and high intensity functional training (HIFT). METHODS: Healthy, non-obese men and women (N=18, age=25±8 yr) who are physically active (PA=7±2hr, VO2max=39±8mL/kg/min) underwent graded exercise testing to determine VO₂max and peak power output (PPO) on the rowing ergometer. On two separate days, subjects performed a time-matched bout of HIFT or HIIT rowing. HIIFT required 6 ‘all-out’ sets of 10 push-ups, 10 jump squats, 20 mountain climbers, and 20 body-weight squats separated by 75 s recovery. HIIT rowing consisted of six 1min bouts at 85% PPO with 75 s of recovery. Gas exchange data, heart rate (HR), affective valence, and RPE were obtained during exercise. Blood lactate concentration (BLa) was measured at rest, bout 3, and 5, 10, and 15 min post-exercise. RESULTS: There were significant differences (p2 was higher (p=0.03) with HIIT rowing versus HIFT (1.88 ± 0.51 vs. 1.67 ± 0.35 L/min) as was total O2 (31±8 vs. 28±6L). GroupXtime interactions (pE, and RPE occurred, with higher values demonstrated to HIFT. CONCLUSION: HIFT elicited a higher peak HR, BLa, and RER, suggesting a higher peak cardiovascular stimulus and greater activation of glycolysis, likely due to greater recruitment of fast twitch fibers. Yet, HIIT rowing elicited higher energy expenditure and mean VO2 versus HIFT. The eccentric nature of HIFT may explain the blunted VO2 response, although more studies are needed to verify this result.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.