Contamination and drop-out rate in the control group by (A) instruction before and (B) intervention during the study intervention period.

a. Instruction ‘exercise allowed’ for control group included: exercise allowed during the study intervention period, including no advice, asked or recommended to exercise. Instruction ‘no change’ for control group included: not to exercise, no change in exercise, continue exercise as it is.
b. Intervention for control group included: information about exercise, education (session) unrelated to exercises, keep exercise diary, use pedometers or accelerometers, phone calls unrelated to exercise, alternative intervention.
c. For contamination data are given in number (percentages) of studies that reported contamination.
Contamination was reported in 30/40 (75%) studies.
d. For drop-out rates data are given in mean ± standard deviation of studies that reported drop out. Drop-out rates were reported in 36/40 (90%) studies.
e. Excess drop-out rate = drop-out rate control group—drop-out rate exercise group.
Contamination and drop-out rate in the control group by (A) instruction before and (B) intervention during the study intervention period.