Skipping your workout, again? Measuring and understanding time inconsistency in physical activity

Given this, and the major public health risks posed by physical inactivity, PA is a popular target for behavioural interventions. However, despite a rich set of such interventions, very few reach the goal of sustainably improving PA habits. 

An insufficient understanding of time inconsistency in PA, and in particular its drivers, is likely an important factor in this failure. Thus, a step back to the drawing board is warranted. We do just that by providing empirical evidence on the prevalence and drivers of time inconsistency in PA using a three-wave longitudinal online survey we ran with a Dutch general population cohort (n = 3,168).

We find that just over one third of our sample is time inconsistent in PA, and that they fail to follow through on just over a third of their ex-ante preferences and plans.  We find no evidence that present bias, the most popular explanation for time inconsistency in the economics literature, is associated with time inconsistency.

We do find evidence of an association of time inconsistency with stress, willpower resources and temptation intensity – three factors predicted by dual-self models of self-control to drive time inconsistency.

We also find evidence of a link between time inconsistency and dynamic inconsistency in risk preferences, as well as trait self-control.  In terms of studies of time inconsistency in PA, this is the first to use such a large representative sample, and the first to go beyond gym attendance by using a broad measure of PA.

This study is also the first to analyse the relationship of time inconsistency with a comprehensive theory-guided list of possible drivers simultaneously.