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Aerobic or Resistance Exercise in Obese Adults

N Engl J Med; 2017 May 18; Villareal, et al

In dieting obese older adults, weight loss plus combined aerobic and resistance exercise was effective in improving functional status, a recent study found. The clinical trial included 160 obese older adults (140 completed the study) and evaluated the effectiveness of several exercise modes in reversing frailty and preventing reduction in muscle and bone mass induced by weight loss. Participants were randomly assigned to a weight management program plus 1 of 3 exercise programs: 1) aerobic training, 2) resistance, or 3) combined aerobic and resistance training; or to a control group (no weight management or exercise program). Researchers found:

  • The Physical Performance Test score increased more in the combination group than in the aerobic and resistance groups, respectively.
  • The scores increased more in all exercise groups than in the control group.
  • Strength increased more in the combination and resistance groups than in the aerobic group.
  • Body weight decreased by 9% in all exercise groups but did not differ significantly in the control group.
  • Lean mass decreased less in the combination and resistance groups than in the aerobic group, as did bone mineral density at the total hip.

Citation:

Villareal DT, Aguirre L, Gurney B, et al. Aerobic or resistance exercise, or both, in dieting obese older adults. N Engl J Med. 2017;376:1943-1955. doi:10.1056/NEJMoa1616338.

Commentary:

Obesity is common with increasing age. In older individuals, approaches that emphasize weight loss alone often result in loss of muscle mass in addition to loss of fat, resulting in increased frailty.1 In a previous study these authors demonstrated that in older individuals, the combination of exercise and weight loss was associated with greater improvement in physical function than weight loss alone or exercise alone.2 Interestingly, not all exercise is the same. Aerobic exercises, like running, increase cardiovascular fitness but do not improve strength. Resistance exercises improve strength but not CV fitness. There is some evidence that aerobic training interferes with the increase in strength that occurs with resistance training.3 The current trial compared 4 groups: a control group without any intervention to 3 groups who received weight management programs with 1 of 3 exercise programs—aerobic training, resistance training, or combined aerobic and resistance training. Results convincingly show that weight loss plus combined aerobic and resistance exercise was more effective than either weight control alone or either of the 2 types of exercise programs combined with a weight control. —Neil Skolnik, MD

  1. Miller SL, Wolfe RR. The danger of weight loss in the elderly. J Nutr Health Aging. 2008;12:487-91.
  2. Villareal DT, Chode S, Parimi N, et al. Weight loss, exercise, or both and physical function in obese older adults. N Engl J Med. 2011;364:1218-29. doi:10.1056/NEJMoa1008234.
  3. Cadore EL, Pinto RS, Lhullier FL, et al. Physiological effects of concurrent training in elderly men. Int J Sports Med. 2010;31:689-97.