
Image: ABC. By Cathy Johnson.
Swimming is great for fitness and muscle tone, but if you’re exercising with your waistline in mind, some might tell you to throw in the towel.
That’s because there’s a belief held by many that swimming is a lousy way to achieve weight loss. But is this really the case?
“If you want to lose weight, you’re better off walking around a pool than swimming in it,” according to Sydney exercise physiologist and personal trainer Andrew Cate.
“That’s obviously a bit extreme, but it does make the point. From a fat-loss perspective, swimming has some real negatives compared to other forms of exercise.”
Buoyancy effect.
It’s true that swimming involves some flotation, and this may reduce the work you have to do to move your body along, compared to land-based exercise — especially if you carry a bit of body fat, which increases buoyancy.
On the other hand, you have to work against the ‘drag’ effect of the water on your body and if your stroke is not very efficient, this may increase the energy you use swimming too.
University of Western Australia academic and researcher Kay Cox agrees there are some potential pitfalls in swimming to whittle your waistline, but she’s shown it can definitely be done.
She led a 2010 study of inactive older healthy women who took up a swimming program and compared them to those who took up a walking program.
The study, published in the journal Metabolism – Clinical and Experimental, showed that after a year on the program, the swimmers had lost more weight and more off their waistlines than those on the walking program.
Both groups exercised at the same intensity (as measured on heart rate monitors) and for the same amount of time three times a week. The first six months they were supervised, they then continued for a further six months unsupervised.
The differences weren’t huge — the swimmers lost an average of 1.1 kilograms more weight and around 2 centimetres more off their waists compared to the walkers.
But it’s nonetheless a significant finding – especially given that very few well-designed studies have ever looked into the issue.
“I think swimming is good for anyone who wants to lose weight,” said Associate Professor Cox, who has a long-term history as a Masters swimming coach.
“It takes the load off your joints compared to running or walking, which means you’re less likely to get injuries and so you’ve got a better chance of sticking with it.”
Cool water and appetite.
Professor Cox believes it’s the cool environment in the pool (26 degrees Celsius) that may explain, at least in part, why the swimmers in her study had the edge when it came to weight loss.
Paradoxically, cool water may also explain why many swimmers find fat hard to budge.
It comes down to the impact of this cool environment on two aspects of the body in the post-swim period: the swimmer’s appetite (which affects how much they eat afterwards) and the energy the swimmer expends to restore their normal body temperature.