Post-exercise metabolic response to kettlebell complexes vs. high intensity functional training

PURPOSE

This study compared the magnitude of excess post-exercise oxygen consumption (EPOC) between kettlebell complexes (KC) and high-intensity functional training (HIFT) and identified predictors of the EPOC response.

METHODS

Active men (n = 11) and women (n = 10) (age 25 ± 6 yr) initially completed testing of resting energy expenditure and maximal oxygen uptake (VO2max), followed by lower and upper-body muscle endurance testing. On two subsequent days separated by ≥ 48 h, participants completed KC requiring 6 sets of kettlebell exercises (pushups, deadlifts, goblet squats, rows, and swings) with 60 s recovery between sets, and HIFT requiring 6 sets of bodyweight exercises (mountain climbers, jump squats, pushups, and air squats) with 60 s recovery. During exercise, gas exchange data and blood lactate concentration (BLa) were acquired and post-exercise, EPOC was assessed for 60 min.

RESULTS

Results showed no difference in EPOC (10.7 ± 4.5 vs. 11.6 ± 2.7 L, p = 0.37), and VO2 and ventilation (VE) were significantly elevated for 30 and 60 min post-exercise in response to KC and HIFT. For KC and HIFT, HRmean and post-exercise BLa (R2 = 0.37) and post-exercise BLa and VE (R2 = 0.52) explained the greatest shared variance of EPOC.

CONCLUSION

KC and HIFT elicit similar EPOC and elevation in VO2 which is sustained for 30-60 min post-exercise, leading to 55 extra calories expended. Results show no association between aerobic fitness and EPOC, although significant associations were revealed for mean HR as well as post-exercise VE and BLa.

Sex-Related Differences in Oxygen Consumption Recovery After High-Intensity Rowing Exercise During Childhood and Adolescence

PURPOSE

To determine sex-related differences in oxygen consumption (V˙O2) recovery after high-intensity exercise during childhood and adolescence.

METHODS

Forty-two boys and 35 girls (10-17 y) performed a 60-second all-out test on a rowing ergometer. Postexercise V˙O2 recovery was analyzed from (1) the V˙O2 recovery time constant obtained from a biexponential model (τ1V˙O2) and (2) excess postexercise oxygen consumption calculated over a period of 8 minutes (EPOC8) and until τ1V˙O2 was reached (EPOCτ1). Multiplicative allometric modeling was used to assess the concurrent effects of body mass or lean body mass, and age on EPOC8 and EPOCτ1.

RESULTS

EPOC8 increased significantly more in boys from the age of 14 years. However, the sex difference was no longer significant when EPOC8 was analyzed using an allometric model including body mass + age or lean body mass + age. In addition, despite a greater increase in EPOCτ1 in boys from the age of 14 years, τ1V˙O2 was not significantly different between sexes whatever age.

CONCLUSION

While age and lean body mass accounted for the sex-related differences of EPOC during childhood and adolescence, no significant effect of age and sex was observed on the V˙O2 recovery time constant after high-intensity exercise.

Interaction between dietary fat and exercise on excess postexercise oxygen consumption

The objective of this study was to determine the effect of increased physical activity on subsequent sleeping energy expenditure (SEE) measured in a whole room calorimeter under differing levels of dietary fat. We hypothesized that increased physical activity would increase SEE. Six healthy young men participated in a randomized, single-blind, crossover study. Subjects repeated an 8-day protocol under four conditions separated by at least 7 days. During each condition, subjects consumed an isoenergetic diet consisting of 37% fat, 15% protein, and 48% carbohydrate for the first 4 days, and for the following 4 days SEE and energy balance were measured in a respiration chamber. The first chamber day served as a baseline measurement, and for the remaining 3 days diet and activity were randomly assigned as high-fat/exercise, high-fat/sedentary, low-fat/exercise, or low-fat/sedentary. Energy balance was not different between conditions. When the dietary fat was increased to 50%, SEE increased by 7.4% during exercise (P < 0.05) relative to being sedentary (baseline day), but SEE did not increase with exercise when fat was lowered to 20%. SEE did not change when dietary fat was manipulated under sedentary conditions. Physical activity causes an increase in SEE when dietary fat is high (50%) but not when dietary fat is low (20%). Dietary fat content influences the impact of postexercise-induced increases in SEE. This finding may help explain the conflicting data regarding the effect of exercise on energy expenditure.