People May Only Notice They’ve Become More Active After More Frequent Vigorous — But Not Moderate — Physical Activity

By Emily Reynolds

Starting a new habit isn’t always easy — we probably only have to look at our own history of failed New Year’s Resolutions to know that. One common frustration is that things don’t happen fast enough — we start doing something that’s supposedly good for us but don’t see a significant behaviour change as quickly as we’d hoped.

That certainly seems to be the case with exercise, at least according to a new study in Frontiers in Psychology. It found that people only feel they’ve become more active when they increase the amount of vigorous activity they do —  if it’s moderate, they don’t feel like they’ve changed at all.

In the first study, Hermann Szymczak from the University of Konstanz and colleagues collected data from 605 participants taking part in a longitudinal study looking at health behaviour. First, participants were asked to report their physical activity for each of the last 7 days: vigorous physical activity, moderate physical activity and walking. Six months later, participants also reported their perceived change in physical activity since the first time point, choosing one statement they felt best summed up their behaviour: “yes, I became more physically active”, “no, but I tried to become more physically active”, “no and I have not tried” and “no, because I was already physically active before”. At both time points, objective fitness was measured via a bicycle test.

In a second study, the same data was gathered from 382 participants from two more time points in the longitudinal study.

The results showed that those who said their behaviour had changed (“changers”) showed an increase in vigorous activity of about 52 and 86 minutes per week in the first and second studies respectively. Changers did not exhibit any changes in moderate activity, however. This suggests that an increase in intense physical activity is much more influential in making people feel that their behaviour has changed. (Changers also showed increased fitness in the bicycle test, at least in the first study).

There are obvious ramifications to these findings. If people only see vigorous activity as a worthwhile endeavour, it could lead to some pushing themselves too hard — and it could put others off completely, meaning they lose the many benefits of even light exercise. Previous research has also suggested this might be the case, so developing public service messaging that makes clear the health benefits of non-intense exercise might have a serious impact.

Future research could look at fitness norms — what narratives exist about moderate and intensive exercise, and how are they disseminated? This could go some way towards understanding why people don’t feel a difference with moderate exercise, as well as informing any changes in messaging to boost motivation and encourage even small behaviour changes.

As the team also notes, perceived behaviour change is a key part of actual behaviour change: if people see positive developments in themselves or their skills, they’re both more likely to believe the changes will last and more able to commit. Thinking about and implementing small changes in behaviour, therefore, may be particularly useful if you’re looking to maintain a habit in the long term. And if you’re feeling bad about a day or week off exercise? Don’t worry — vegging out is just as necessary sometimes.

An Increase in Vigorous but Not Moderate Physical Activity Makes People Feel They Have Changed Their Behavior

Emily Reynolds is a staff writer at BPS Research Digest