The effects of self-monitoring and reinforcement on exercise adherence

Abstract

Two behavioral techniques were assessed to determine their effects on subjects' adherence to unsupervised exercise. The subjects were 35 moderately fit persons who had just completed an adult fitness program (AF group) and 42 sedentary individuals who were recruited through the campus newspaper (NEWS group). Participants were randomly assigned to one of three conditions: (a) self-monitoring, (b) reinforcement supplied by another person, or (c) control. All subjects were given instructions on how to exercise and asked to exercise on their own for 18 weeks. Self-monitoring subjects kept written records of their exercise behavior, while reinforcement subjects verbally reported their exercise behavior to another person who periodically administered rewards. Pre- and posttreatment tests on the NEWS group revealed no significant treatment or interaction effects. However, the reinforcement group had an 11% improvement in predicted max VO2 and a 9 bpm improvement in exercise heart rate compared to 7.8%, 5 bpm for the self-monitoring (SM) group and 5.3%, 6 bpm for the control group. T-tests indicated that reward and SM groups improved significantly on these variables, whereas the control group did not. SM (M = 2.07) and reinforcement (M = 2.29) groups reported a significantly higher frequency of exercise per week than the control (M = 1.36) group. The AF subjects were able to maintain their fitness level (with the exception of a small increase in body fat) over the 18-week period. The behavioral interventions had little differential effect on adherence by AF subjects who were already regular exercisers.