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Effect of High Intensity Interval Training (HIIT) on Substrate Utilization
Author(s) -
Roberson Daniel W,
Astorino Todd A,
Allen Ryan P,
Trost Emily,
Jurancich Matthew
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.618.10
Subject(s) - high intensity interval training , interval training , respiratory exchange ratio , medicine , physical therapy , zoology , cardiorespiratory fitness , cycle ergometer , time trial , exercise physiology , heart rate , biology , blood pressure
High‐intensity interval training (HIIT) provides a powerful stimulus that elicits similar physiological changes, such as increased VO 2 max and fat utilization, as traditional endurance training. However, the majority of studies employing this training regimen have used sedentary subjects, so it is unknown if it is still effective in active individuals. PURPOSE The primary aim of the study was to examine the effect of HIIT on substrate utilization in recreationally active men and women. METHODS Ten men and women (mean age and physical activity equal to 25.7 ± 5.18 yr and 7.0 ± 2.8 h/wk, respectively) completed HIIT consisting of 6 d of training (4 – 6 Wingate tests per day) over 3 wk. They regularly participated in cardiovascular exercise, resistance training, and/or sports, yet none were athletes. VO 2 max was measured pre‐ and post‐HIIT on the cycle ergometer. Via indirect calorimetry, substrate utilization was evaluated pre‐ and post‐training during 30 min of cycle ergometry, consisting of three 10 min bouts at 50, 60, and 70 % maximal workload (Wmax). Respiratory Exchange Ratio (RER) was used to assess substrate utilization, with gas exchange data averaged every five minutes. Subjects came to the laboratory after a minimum 3 h fast. Data were analyzed using a two‐way ANOVA with repeated measures. RESULTS VO 2 max was increased by 6 % with HIIT. There was a significant effect (p < 0.05) of HIIT on substrate utilization across time. For example, at 25 minutes of exercise, RER post‐training was equal to 0.96 ± .04 versus 0.99 ± .05 at baseline, indicating a 10 % increase in fat utilization. CONCLUSION Data from this preliminary study reveal that HIIT significantly alters (p < 0.05) RER, in the form of increased fat utilization, in active men and women.