Do they really promote greater physical activity?

Or are they just toys?

Electronic trackers monitor various aspects of physical activity to let us know the extent of our activity. But the more important function is to motivate those who use trackers to increase or at least maintain their levels of physical activity. Do trackers employ effective behavior change techniques (BCTs)? Researchers in Texas investigated this question for 13 commercially available physical activity monitors. Behavior change taxonomies have identified 26 to 93 different BCTs. Fifteen of them appeared to be potentially effective based on their success in previous interventions. These BCTs included 1) prompt practice, 2) prompt self-monitoring of behavior, 3) goal-setting / intention formation, 4) barrier identification / problem solving, 5) provide feedback on performance, 6) prompt review of behavior goals, 7) provide information on consequences of behavior in general, 8) action planning, 9) prompt rewards contingent on effort or progress towards behavior, 10) facilitate social comparison, 11) provide instruction, 12) self-talk, 13) self-rewards, 14) social support, and 15) teach to use prompts / cues. All 13 monitors provided tools for self-monitoring, feedback, and environmental change. Ten of 13 monitors used goal setting and discrepancy between current and goal behavior. Half of the monitors also used goal setting, self-monitoring, and feedback that mirrored recommendations from social cognitive theory. Thus, physical activity monitors employ a range of BCTs that are used in clinical behavioral change interventions. Monitors could serve as relatively inexpensive means to move BCTs into widespread use.

While physical activity clearly promotes better health, only 31 percent of adults globally get the recommended minimum amount of moderate-intensity physical activity. Wearable activity monitors may offer a practical way increase daily physical activity. Researchers in Australia conducted a systematic review (28 studies) and meta-analysis (26 studies) of controlled trials with adult participants. Compared to controls, participants in interventions using wearable physical activity trackers significantly increased their daily step counts, moderate and vigorous physical activity, and energy expenditure with small effects. These increases equated to 627 extra daily steps and 75 extra weekly minutes of moderate and vigorous physical activity. Multi-faceted interventions that involved trackers and other techniques showed even greater increases in daily steps (685) and moderate and vigorous physical activity (92 minutes). Increased physical activity of wearing trackers also led to an extra 300 calories burned per week. The trackers did not lead to significant declines in sedentary times. Trackers can significantly increase physical activity over the short term. Long-term effects remain unknown.

Numerous articles, systematic reviews, and meta-analyses report results of trials wearable activity trackers. The available evidence suggests that activity trackers promote greater physical activity. Yet, controversy exists regarding the effectiveness of trackers and possible negative effects. A group of Australian researchers conducted an umbrella review of 39 systematic reviews and meta-analyses of activity trackers to help clarify their effectiveness. Analyses showed that activity trackers increased physical activity and fitness with moderate effect sizes. These improvements translate into an additional 1,800 steps per day, 40 minutes per day of walking, and body weight loss of one kg. Activity trackers tended to significantly reduce body-mass index, body weight, waist circumference, and aerobic capacity. Psychosocial and quality of life outcomes from wearing activity tackers tended to be neutral or positive but statistical non-significant. Positive results of activity trackers appeared to be relatively durable, lasting for six months, and occurred for both general and clinical populations. None of the analyses revealed evidence of negative effects of trackers. Overall, this umbrella review provides strong evidence that activity trackers can help a wide variety of people increase their level of physical activity and fitness.

Wearable physical activity trackers can help people increase their level of physical activity. Does this finding extend to patients with cardiometabolic conditions? A new systematic review and meta-analysis of 34 randomized clinical trials with 4,203 participants with cardiometabolic conditions found that pedometers, but not accelerometers / fitness trackers, led to a significant, albeit modest, average increase of 1,877 steps per day compared to the control groups. Studies that included consultation with a health care professional and in which men predominated tended to have larger daily step gains. Interestingly, all but one of the studies included primarily middle-aged and older participants with an average age of at least 49 years. The lack of a statistically significant effect of wearing an accelerometer or fitness tracker may have reflected the paucity of younger participants. In any event, an inexpensive pedometer can keep track of your daily steps, which might motivate you to increase and maintain your daily step count.

Physical activity predicts better prognosis following cancer diagnosis. However, cancer patients typically decrease their levels of physical activity after diagnosis. Would wearable physical activity monitors lead to increases physical activity of cancer patients? Researchers in Australia conducted a systematic review and meta-analysis of 35 controlled intervention trials that involved wearable devices (and sometimes other factors such as baseline counseling). Trials lasted from four weeks to one year. Compared to controls, interventions with wearable trackers led to significant increases in weekly combined moderate- and vigorous-intensity physical activity, moderate-intensity physical activity, total activity, and daily steps with moderate to large effect sizes. In addition, interventions with wearable trackers also led to significant increases in quality of life, aerobic fitness, physical function, and less fatigue with small to moderate effect sizes. The interventions appeared to be acceptable with low levels of adverse events. One note of caution: The quality of the included studies ranged from low to very low. Wearable physical activity trackers could be an important part of multi-component interventions to help cancer patients increase their levels of physical activity.