Acute Cardiorespiratory and Metabolic Responses in Kettlebell High-Intensity Interval Training versus Sprint Interval Cycling

Abstract

High-intensity interval training (HIIT) has become a popular training modality due to similar adaptations it can produce in comparison to traditional aerobic training and the time-efficiency it provides. A common form of HIIT is sprint interval cycling, however little empirical evidence exists regarding the effects that other modalities of HIIT produce. One promising modality is kettlebell exercise. PURPOSE: To compare cardiorespiratory (CR) and metabolic (MB) responses of a KB-HIIT protocol to a sprint interval cycling (SIC) protocol. METHODS: Eight male participants (21.5±0.86 yrs) volunteered for this study. They completed two preliminary sessions (an informational session and a CR fitness and anthropometric assessment session), as well as two 12-min experimental sessions (KB-HIIT and SIC) in a counterbalanced-randomized fashion. CR and MB responses were measured across both experimental sessions. In the KB-HIIT bout, the participants performed three circuits of four exercises (sumo squat, swings, clean & press, and sumo deadlift) using a Tabata protocol (20-sec of exercise, 10-sec of rest). In the SIC bout, the participants performed three 30-sec sprints at an “all-out” effort, with 4-min of recovery after sprints 1 & 2 and 2-min after sprint 3. Group (2) x time (12) effects were determined for oxygen consumption (VO2), respiratory exchange ratio (RER), tidal volume (TV), breathing frequency (fB), minute ventilation (VE), caloric expenditure rate (kcal/min), and heart rate (HR). Additionally, total caloric expenditure (kcals) was compared. RESULTS: In addition to a significant (p<0.05) time effect and group x time interaction, there was a significant group effect for VO2 [F(1,14)=4.886, p<0.05], RER [F(1,14)=133.151, p<0.001], and TV [F(1,14)=10.416, p<0.05]. In the KB-HIIT bout vs. the SIC bout there was a higher mean (±SE) VO2 [22.6±1.48 vs.19.9±1.01 ml/kg/min] and lower mean (±SE) for RER [0.93±0.02 vs. 1.22±0.04 l/min] and TV [1.7±0.07 vs. 2.2±0.15 l/min]. There was only a significant (p<0.05) time effect and group x time interaction for fB, VE, kcal/min, and HR. Total caloric expenditure was also significantly higher during the KB-HIIT bout vs. the SIC bout [144.87±6.56 vs. 122±7.34 kcals, p<0.05]. CONCLUSIONS: The findings of this study offer new evidence that KB-HIIT is an effective form of HIIT for eliciting CR and MB responses essential for aerobic fitness adaptation.