So here’s something I’ve been wondering about recently. I use a Garmin GPS watch to track my daily running mileage. It definitely motivates me to hit a specific mileage goal each morning because I’m accountable to the numbers. Without it, I’m more prone to stopping short if I end up back at the house a little earlier than planned. Indeed, most evidence suggests that activity monitors are effective training tools for physically active individuals. But what about their use for inspiring physical activity in less active individuals? Can you give the gift of exercise simply by giving a sedentary friend a Fitbit?
A recent study of 13 monitors (including Jawbone, Fitbit, and Nike monitors) concluded that all monitors provide tools for self-monitoring and feedback, using established and valid clinical techniques such as goal-setting, social support, prompts/cues and rewards. But do these behavior change techniques, which are commonly used in research interventions, actually work for the average wearer? In other words, do they increase physical activity in sedentary adults, rather than simply reinforcing activity patterns in already active adults?
I turned to the research literature to answer this question. One study looked at using prizes to increase physical activity in 11 adults wearing Fitbits. In this study, 11 healthy adults wore Fitbit accelerometers for 3 weeks, earning prize draws for wearing the Fitbit. Four subjects increased step counts as a result of the intervention, an underwhelming number which suggests that without prizes, the Fitbit in and of itself might not be especially effective for increasing physical activity.
In another study involving medical residents (a motivated and highly health-educated population), half of the 104 study participants were given physical activity monitors to wear. The other half (non-wearers) served as the control group. Monitors did NOT increase daily physical activity of the residents relative to the control group, as there was no difference in average steps/day taken between the two groups. Study authors then entered all participants into another phase: a team competition. Everyone (all 104 residents) wore physical activity monitors and competed for team honors in most steps/day taken. Residents who wore the monitors in the first round did indeed increase their physical activity when they participated in the team competition in the second phase.
The idea that there has to be an incentive tied to an activity monitor to have it work has already been established with pedometers. A meta-analysis of studies looking at increasing physical activity with pedometer-based interventions found that one of the most significant predictors of effectiveness was having a step goal (like 10,000 steps/day). For example, if people are given a pedometer and encouraged to meet a specific step goal, then they are more likely to increase physical activity and lose weight.
So the take home message is that physical activity monitors themselves are likely not sufficient motivation to increase physical activity. Participants need to be incentivized by a competition, a goal, or the opportunity to win something. So, if this holiday season you are hoping to give the gift of fitness and health to a loved one, don’t just wrap up a Fitbit and put it under the tree. Set up a family competition, or a prize structure, or even just a healthy steps goal, to make the Fitbit translate into fitness.