Maternal resistance exercise increases infant energy expenditure.

Maternal obesity decreases infant energy expenditure, subsequently predisposing infants to greater adiposity and weight gain. Conversely, some findings suggest that maternal exercise may increase infant energy expenditure; however, the impact of maternal exercise mode (i.e., aerobic or resistance exercise) on infant energy expenditure is not known. The purpose of this study was to investigate whether supervised maternal exercise [aerobic, resistance, and combination (aerobic + resistance)] affects infant energy expenditure. When weight-adjusted resting energy expenditure was determined at 1 mo of age, infants exposed to resistance exercise in utero had >35% higher energy expenditure compared with infants exposed to aerobic exercise or no exercise. In addition, infant energy expenditure and lean mass were associated with maternal blood lipids independent of exercise mode. The increase in infant resting energy expenditure with the addition of any resistance exercise during gestation resulted in a discrepancy between measured and estimated energy expenditure using common estimation equations. These results implicate maternal metabolic health in determining infant metabolic rate, and maternal resistance exercise during pregnancy as a lifestyle intervention to increase infant energy expenditure potentially decreasing the subsequent infant adiposity gain. ClinicalTrials.gov Identifier: NCT03838146 and NCT04805502. Maternal resistance exercise increases infant energy expenditure. This increase creates a gap between the measured and estimated energy expenditure when using standard estimation equations. These findings suggest that maternal resistance exercise can serve as a nonpharmacological method to enhance an infant's daily caloric expenditure.