You’re probably somewhat familiar with intrinsic and extrinsic motivation, and odds are you’ve heard the following: intrinsic motivation comes from within, while extrinsic motivation comes from without. Intrinsic motivation is better because it is self-sustaining. Extrinsic motivation can produce short-term results, but it’s bad because it undermines intrinsic motivation, so it backfires in the long run.
That’s the pop-psych view of motivation. And it is accurate…in some cases. But as is often the case, the reality is a bit more complex. One literature review found that undermining effects were well-supported in economic research, but not in health research.18 The authors attribute this partly to the fact that most health studies use subjects who initially have low levels of motivation for health-related behavior; they found that extrinsic incentives are more likely to reduce intrinsic motivation when intrinsic motivation is high to begin with.
A 2016 experiment found that obese women on a behavioral weight loss program lost significantly more weight when the program was paired with small financial incentives. Moreover, members of the experimental group showed significantly higher extrinsic and intrinsic motivation compared to women who were not given financial incentives. However, weight regain during the post-study period was not significantly different between the two groups.
These two studies suggest that extrinsic incentives are likely to be more helpful for novice trainees, particularly obese ones, but less effective- possible counterproductive- for intermediate and advanced trainees. However, it’s important to remember that most studies use financial incentives, and non-financial incentives may have different effects. It’s possible that if the offered incentive is something directly related to fitness- such as new gym gear or cooking tools- it might very well support intrinsic motivation by inducing cognitive dissonance. Unfortunately this hasn’t been tested in a lab setting yet, but it is a ripe area for future study.
Another study did find that cognitive dissonance could be used to enhance intrinsic motivation. Husted and Ogden found that reminding bariatric surgery patients how much they had invested in weight loss by getting bariatric surgery caused them to report significantly less enjoyment of high-calorie foods and less desire to eat said foods. More importantly, they lost 6.77 kg in the three months after this intervention, compared to just .91 kg for a control group.20 Reminding people of the effort they’ve already made to get into shape appears to be very effective.
One meta-analysis of motivational studies (not all of them health-related) found that while tangible incentives often reduce intrinsic motivation, verbal praise tends to increase it.21 This may be a cognitive dissonance effect- praise feels good but has no tangible value. On the other hand, it could very well be mediated by changes in the recipient’s self image. That is, being praised for doing X causes the recipient to view themselves as someone who does X.