Cardiometabolic and Perceptual Responses to Body-Weight Resistance High-Intensity Interval Exercise in Boys

Abstract

The majority of studies examining children’s responses to high-intensity interval exercise primarily utilized running; however, this modality does not require/include other important aspects of physical activity including muscular fitness. Purpose: To compare acute responses between a body weight resistance exercise circuit (CIRC) and treadmill-based (TM) high-intensity interval exercise. Method: A total of 17 boys (age = 9.7 [1.3] y) completed a graded exercise test to determine peak heart rate, peak oxygen uptake (VO2peak), and maximal aerobic speed. Sessions were randomized and counterbalanced. CIRC required 2 sets of 30-second maximal repetitions of 4 exercises. TM included eight 30-second bouts of running at 100% maximal aerobic speed. Both included 30-second active recovery between bouts. Blood lactate concentration was measured preexercise and postexercise. Rating of perceived exertion, affective valence, and enjoyment were recorded preexercise, after intervals 3 and 6, and postexercise. Results: Participants attained 88% (5%) peak heart rate and 74% (9%) VO2peak for CIRC and 89% (4%) peak heart rate and 81% (6%) VO2peak for TM, with a significant difference in percentage of VO2peak (P = .003) between protocols. Postexercise blood lactate concentration was higher following CIRC (5.0 [0.7] mM) versus TM (2.0 [0.3] mM) (P < .001). Rating of perceived exertion, affective valence, and enjoyment responses did not differ between protocols (P > .05). Conclusion: HR responses were near maximal during CIRC, supporting that this body-weight circuit is representative of high-intensity interval exercise.