Promoting Strength Training Among Baby Boomers: Message Framing Effects on Motivation and Behavior

Regular participation in strength training significantly enhances older adults' physical and functional health, yet only 14% of adults over age 50 report engaging in strength training at least twice per week. Exercise messages about why and how older adults should engage in strength training could influence their perceptions of and participation in the behavior. This study was designed to promote strength training among adults aged 50-70 and to determine whether the message frame accompanying a brief workout would have an impact on participants' motivation, self-efficacy, and/or physical activity behavior.

Participants (N = 308) were randomly assigned to one of four message conditions: Easy Intrinsic, Hard Intrinsic, Easy Extrinsic, or Hard Extrinsic. Immediately after completing baseline measures of motivation and physical activity, participants received the recommended strength training workout and corresponding motivational message. They completed follow-up measures of motivation and physical activity 2 weeks later.

Controlled regulation was higher at follow-up among participants exposed to an extrinsic message relative to an intrinsic message (F(3,208) = 3.08, p = .03). Strength training (Z = - 5.95, p < .001) and moderate physical activity (Z = - 3.23, p = .001) increased among participants not engaging in regular strength training at baseline.

These results suggest message framing may have a short-term impact on Baby Boomers' physical activity motivation, such that emphasizing extrinsic goals (i.e., weight loss and appearance) may contribute to controlled motivation. However, repeated measurements are needed to determine the longer-term maintenance and influence of these effects.