The effects of goal setting on increasing physical activity behavior through a 16-week internet-delivered intervention.

摘要

The effects of goal setting on increasing physical activity (PA) levels in middle-aged female adults, through a goal-setting modification to a previously validated internet-delivered PA behavior change program was investigated. Purpose: The purpose of this study was to determine whether middle-aged female adults who complete a 16-week internet-delivered PA behavior change intervention with prescribed goal setting realized a greater change in PA behavior and improvements in cardiometabolic disease factors compared to those who completed the same intervention but without prescribed goal setting. Methods: Forty-three female participants completed the 16-week Active Living Every DayRTM (ALED) PA behavior change program, of which 21 were randomly assigned to receive a monthly progressive step goal (Goal group; +625 steps/day/month) over the 4-month period (2500 steps/day total increase). The remaining 22 participants were not assigned a goal (No Goal group), but had access to the identical behavior change features inherent within the ALED program as the Goal group. At baseline and 16-weeks, PA (pedometer) and the following caridometabolic disease variables were measured: (1) predicated VO2 peak (ml/kg/min), (2) systolic blood pressure (mmHg), (3) diastolic blood pressure (mmHg), (4) BMI (kg/m2), (5) weight (kg), (6) body fat (%), (7) lean tissue mass (%), (8) total cholesterol (mg/dL), (9) LDL cholesterol (mg/dL), (10) HDL cholesterol (mg/dL), (11) triglyceride (mg/dL), (12) fasting plasma glucose (mg/dL), (13) fasting insulin (mg/dL), and (14) waist circumference (cm). Participants logged/reported their PA for at least five of seven days per week including one weekend day. Multiple day data allowed calculation of weekly steps/day means, physical activity variability as well as weekly minimum and maximum PA. Results: At baseline, the No Goal group (active control) and the Goal group (intervention group) were similar in age and other descriptive/anthropometric characteristics with the exception of waist circumference. Participants in the No Goal group had a greater waist circumference (94.7 +/- 3.1 cm) than the Goal group participants (83.8 +/- 1.9 cm), however, body mass index, weight, and percent body fat were similar between the groups. After accounting for baseline differences, the reduction in central adiposity of 2.1 cm in the No Goal group was statistically significant (p≤0.05) when compared to the change of 1.3 cm (p=0.2) in the Goal group. Predicted aerobic fitness increased significantly and similarly in both groups after the 16-week PA behavior change program. The No Goal group increased PA by 1170 steps per day (8479+/-579 to 9649+/-579; p<0.008) from baseline compared to the Goal group who increased steps per day by 237 (8946+/-593 to 9211+/-593; p=0.87). Despite the insignificant increase in PA observed in the Goal group, the subject's least physically active day (minimum) increased by 22% (5149+/-599 to 6575+/-599 steps; p=0.019), and physically activity variability (standard deviation steps/day) decreased by 26.8% (p=0.018). Conclusions: The 16-week internet-delivered ALED behavior change program, without enhanced goal setting, increased physical activity and aerobic fitness and reduced central adiposity. However, addition of prescribed goal setting to the ALED program did not result in greater increases in physical activity or improvements in cardiometabolic disease factors, and in fact diminished the health promoting effect of ALED. Goal setting does appear to favorably influence physical activity consistency and reduce weekly inactivity. These findings suggest that continued investigation of goal setting in pedometer-based physical activity interventions is warranted.