Thirty-two studies (5,328 participants) were included: 24 assessed effectiveness, 22 assessed adherence and 14 assessed both of these. Twelve of the 24 effectiveness studies were rated high quality and 12 were rated low quality. PEDro scores ranged from 4 to 7 (median 6).
Sixteen studies (eight high quality and eight low quality) were classified as frequent contact and 12 of these had a non-active comparison group and results were conflicting. Effects on physical capacity measures in the intervention groups were either comparable to or significantly better than those in the control groups. In four studies that compared remote feedback with supervised exercise sessions, remote feedback groups were as effective at enhancing physical capacity as the control group.
Five studies assessed non-frequent remote contact (two high quality and three low quality). Results were consistent in that effects on physical capacity measures were significantly larger in the intervention groups of studies with an inactive control group or comparable in studies with an active control group (supervised exercise).
Three studies assessed direct remote feedback (internet, video or telephone; two high quality and one low quality). Results showed that physical activity declined significantly less with remote feedback than with usual care and there were similar effects on physical capacity measures as for supervised exercise.
Adherence rates ranged between 32.1% and 91% (22 studies). Adherence was higher when providing remote feedback than in the control groups without feedback.