The Effect of Resistance Training on the Resting Metabolic Rates of Apparently Healthy Adult Women

Abstract

Recent literature has suggested that resting metabolic rate (RMR) significantly contributes to total daily energy expenditure. Total daily energy expenditure impacts caloric balance. Literature has also suggested that aerobic and anaerobic physical activity can increase RMR, and that RMR is positively correlated to lean muscle mass. PURPOSE: This study examined the effects of six weeks of functional resistance training on the RMR in apparently healthy adult women (n=20), and examined the effects of age and body mass index (BMI) on change in RMR after training. METHODS: Participants in this study were females between 35 and 60 years of age, and had a BMI between 18.5kg/m2 and 39.9kg/m2. All participants had body composition and RMR examined before and after a 6 week resistance training program to determine if any changes had resulted from the training. Changes in absolute and relative RMR were compared by age group (35-50 and 51-60) and BMI category (18.5-24.9 kg/m2, 25-29.9 kg/m2, and 30-39.9 kg/m2). RESULTS: Results are expressed as Mean ±Standard Deviation. Results indicated a significant increase in absolute (236.4 ±242.01 kcal/day, t=4.02, p=.001), and relative (3.4 ±3.7 kcal/kg/day, t=3.79, p=.002) RMR in the sample. No statistically significant differences were found when comparing amount of change across age or BMI category. CONCLUSIONS: Literature suggests that exercise training can increase RMR. This study supports that hypothesis, and suggests that 6 weeks of resistance training is adequate to elicit an increase in RMR in healthy adult women. A possible mechanism explaining this effect is an increase in neuromuscular recruitment or muscular activation with the initiation of resistance exercise from a sedentary state. More research is needed to examine this mechanism; and to determine the effects of age, body composition, and different styles of training on this change.