Acute Cardiometabolic and Perceptual Responses to Individual and Group-Based Body-Weight Resistance Exercise in Girls

Abstract

Girls’ acute responses to group-based high-intensity interval exercise (HIIE) are not well characterized. Purpose: To compare acute responses to treadmill-based HIIE (TM) and body-weight resistance exercise circuit (CIRC) and to CIRC performed in a small-group setting (group CIRC). Method: Nineteen girls (9.1 [1.1] y) completed exercise testing on a TM to determine peak oxygen uptake, peak heart rate (HRpeak), and maximal aerobic speed. The TM involved eight 30-second sprints at 100% maximal aerobic speed. The CIRC consisted of 8 exercises of maximal repetitions performed for 30 seconds. Each exercise bout was followed by 30 seconds of active recovery. The blood lactate concentration was assessed preexercise and postexercise. The ratings of perceived exertion, affective valence, and enjoyment were recorded at preexercise, Intervals 3 and 6, and postexercise. Results: The mean heart rate was higher during group CIRC (92% [7%] HRpeak) than CIRC (86% [7%] HRpeak) and TM (85% [4%] HRpeak) ( = .49). The mean oxygen uptake equaled 76% (11%) of the peak oxygen uptake for CIRC and did not differ from TM (d = 0.02). The CIRC elicited a greater postexercise blood lactate concentration versus TM (5.8 [1.7] vs 1.4 [0.4] mM, d = 3.61). The perceptual responses were similar among conditions (P > .05), and only the rating of perceived exertion increased during exercise ( = .78). Conclusion: Whether performed individually or in a small group, CIRC represents HIIE and may be a feasible alternative to running-based HIIE.