Parallel controlled trials of aerobic exercise interventions (lasting at least four weeks) in women with breast cancer, that measured cardiopulmonary function and/or body composition, were eligible for inclusion. Included trials were required to have a minimum of five participants. Trials including interventions that were solely weight training, movement therapy, flexibility or stretching exercises were excluded. Trials were excluded if they were pilot studies, if there was obvious bias in the allocation to intervention or control groups, or if the effects of an exercise intervention could not be separated from a multiple intervention.
Included trials assessed moderate intensity aerobic exercise only (cycle, ergometre, walking, or aerobic exercise) or aerobic and resistance exercise interventions, with a median duration of 30 to 40 minutes per session and a median frequency of three times weekly, compared with control groups continuing with their usual lifestyle. In one trial, the control group participated in discussions about routine care of breast cancer; another control group participated in stretching exercise only. The duration of the interventions ranged from six to 26 weeks. Women in included trials underwent chemotherapy, radiotherapy or combined radio and chemotherapy adjuvant treatment; their mean age was 51.1 years; they had breast cancer stages 0 to III; their mean body mass index was 27.7kg/m2.
Outcomes reported were absolute peak oxygen uptake, relative peak oxygen uptake, the distance covered in 12 minutes of brisk walking, body weight, percentage body fat, and lean body mass. The majority of the included trials were conducted in the USA; the remainder were carried out in the UK and Canada.
The authors did not state how the studies were selected for review.