One of the most interesting thing about a lot of habit-based interventions is that many don’t do wildy better than other interventions in randomized control trials. They seem to do the same or maybe a tiny bet better. 12 weeks, however (the usual length of time for a nutrition or physical activity intervention) does not usually tell the whole story. Carels et. al (2014) have added to this understanding with a 6 month follow-up to a 12 week obesity intervention that showed an interesting result. All of the participants in the habit-based intervention group showed up to the follow-up meeting (the post-study dropout rate was much higher in the other group) and the habit group kept the weight off better. This study measured a lot of variables (self-image, eating and physical activity habits, body image, etc.) and found that even though there were not significant differences between the two groups at 3 and 6 months, the habit-based group held the weight off better. The study was small (n=59), but there are frankly not a lot of these RCTs available. I hope we start to see more of them using standardized measures (like this study did) so that proper meta-analysis can get underway. It’s one thing to talk about the impact of habits-based interventions, it’s quite another to spend money on researching them

Carels, R. A., Burmeister, J. M., Koball, A. M., Oehlhof, M. W., Hinman, N., LeRoy, M., … Gumble, A. (2014). A randomized trial comparing two approaches to weight loss: Differences in weight loss maintenance. Journal of Health Psychology, 19(2), 296–311. doi:10.1177/1359105312470156


We know that willpower is limited by “something” and that lab studies have done a good job of showing the breadth of things that can deplete our precious reserves (like resisting fresh-baked cookies). Bertrams and Paul (2014) take these lab studies another steep by asking, “what happens if people get interrupted by other people between willpower-based tasks?” They took 34 people in 2 groups and put them through a willpower depleting task. On their way to another task, half the participants were “interrupted” by two female colleague. You know that awkward dance when you don’t know how to get around people headed your way? Yeah, that’s all they did. The other group didn’t run into anyone on their way to the next task. Turns out the group that was “socially interrupted” took 45 seconds longer to complete the next willpower-based test than the control group. What’s the lesson here? As coaches, it is not only possible to get in our clients’ way, it’s incredibly easy to do so without noticing it.

Bertrams, A., & Pahl, S. (2014). Ego Depletion After Social Interference. Psychology, 5, 1.


When I wrote my Master’s Thesis, I made a prediction: if you give people a choice in what they are working on, they will pursue it longer because they feel more autonomous. Turns out, according to Wulf, Freitas, and Tandy (2014), I was right! They took two groups of equal fitness and gave them a workout to do. One group got to choose the order of the workouts, the other did not. The group that got to pick their exercise order did 39.60 reps whereas the control group only did 24.29 reps! It was surprising to me that this had never been studied because I have seen the benefits of incidental choice as a coach for years, but thus is the state of exercise psychology. I have written more about incidental choice in this issue’s Concept of the Month.

Wulf, G., Freitas, H.E., Tandy, R.D. (2014). Choosing to exercise more: Small choices increase exercise engagement. Psychology of Sport & Exercise. doi: 10.1016/ j.psychsport.2014.01.007