aerobic exercise training, [beta]-adrenergic receptor blockers, body weight, hypertension, negative energy balance



  1. Belanger, Mathieu MSc
  2. Boulay, Pierre PhD


PURPOSE: There is substantial evidence that the use of [beta]-adrenergic receptor blockers ([beta]-blockers) is associated with a reduction in resting metabolic rate (RMR) and that a weight gain usually occurs in the first few months of treatment. The purpose of this study was to determine if RMR of overweight and sedentary subjects consuming [beta]-blockers can be increased following an aerobic exercise training program.


METHODS: Twenty-four subjects participated in the study; 11 (6 women, 5 men) were treated with [beta]-blockers for hypertension and 13 (9 women, 4 men) were nonmedicated (control group). Body composition, RMR, and peak oxygen uptake ([latin capital V with dot above]O2peak) were assessed for all subjects before and after a 12-week aerobic exercise training program. Weekly exercise energy expenditure equaled 83.68 kJ (20 kcal) per kg of body weight while exercise intensity was maintained between 60% and 70% of the [latin capital V with dot above]O2 reserve.


RESULTS: Body composition, RMR, and [latin capital V with dot above]O2peak did not differ among groups at the beginning of the study. Body weight (-1.4 kg for [beta]-blockers, P < .05; -2.5 kg for control, P < .05) and [latin capital V with dot above]O2peak (+2.2 mL[middle dot]kg-1[middle dot]min-1 for [beta]-blockers, P < .05; +4.1 mL[middle dot]kg-1[middle dot]min-1 for control, P < .001) were significantly improved in both groups, whereas RMR (-272 kJ[middle dot]day-1 for [beta]-blockers, NS; +573 kJ[middle dot]day-1 for control, P < .05) was increased only in the control group after the aerobic exercise training program.


CONCLUSIONS: These results suggest that [beta]-blockers limit the increase in RMR normally observed following an aerobic exercise training program. Consequently, obtaining a negative energy balance in an attempt to lose weight may be more difficult.