The most popular New Year resolution in almost every survey is “exercise more” – which often translates into joining a gym. According to the 2016 State of the UK Fitness Industry report, one in seven people in the UK are members. But are they more likely to be fit?

The solution

A study last week in the journal Plos One found that gym members were 14 times more aerobically active than people who didn’t belong to any health club. Gym members, on average, did six hours more exercise a week, and this activity did make them fitter than non-members. They had lower heart-rates, smaller waists and higher levels of cardiovascular fitness as measured by heart strength, lung function and muscle mass. They also spent less time sitting down every day than non-gym members. The results were similar for men and women.

The study included 405 people between the ages of 30 to 64, and the general characteristics of those who were gym members were similar to those who were not. The lead author, Elizabeth C Schroeder of the department of kinesiology and nutrition at the University of Illinois, says that gym members were also more likely than non-members – even those who did exercise – to do resistance training which strengthens muscles, reduces blood pressure and can increase metabolic rates.

While it might seem obvious that gym members exercise more, and are healthier than non-members, Schroeder says this has not previously been explicitly shown. “This study adds actual objective measures of people at a health club compared with non-members, which has not been measured prior [to now],” she says. However, the study is only designed to show a link between gym membership and more exercise – it may be that active people are just more likely to join gyms. People in the study who exercised as much as gym members had similar reductions in cardiovascular risk factors.

You can get broadly the same benefit wherever you exercise. This study shows a gym membership makes it more likely you’ll do so, but other research shows that exercising outside has other benefits. Outdoor activity can boost your vitamin D levels, reduce tension and depression, and make you feel more revitalised and positive about life – especially if you run through a forest.

Outdoor exercise is also rated as more enjoyable and less of an effort than going to the gym. The first five minutes of outdoor exercise are particularly effective at making people feel good. But Schroeder says that a gym may also encourage greater exercise because it can be social and fun.