Worried your training might put a strain on your body? Here are the facts that prove it will keep you fit for life!

Words by Peta Bee

It’s been shown to extend your life, trim your waistline and ward off killer diseases. But one personal trainer recently discounted scientific evidence and suggested that running is a dangerous activity that comprises seven deadly sins. Greg Brookes, a London-based fitness trainer, has attracted much media attention with his controversial claim that running is bad for you. However, experts say Brookes has distorted facts and twisted findings. Here, we analyse Brookes’s running myths and find out the truth from the scientists.

“It decreases the size of your heart”

Brookes claims that “if you force the heart to keep running for long periods of time, it will naturally shrink to use less energy.” Sports scientists who have studied the effects of running on the heart have proven it is among the most effective means of strengthening the cardiovascular system. “To suggest that a runner’s heart would shrink to use less energy is nonsense,” says John Brewer, professor of sport at the University of Bedfordshire. “Endurance running increases the size of the heart, in particular the left ventricle – the main chamber of the heart responsible for pumping blood around the body.” A recent examination of Olympic marathon Champion Sammy Wanjiru found that the size of his heart greatly exceeded that expected for someone of his age and size, and Brewer says this is true of many runners.

“It causes injury through repetitive movements”

This is an age-old claim that has been disproven countless times by scientists. Running is a high-impact sport and is as likely to result in injuries as any other activity. But it is poor technique rather than the action of running itself that causes problems. A recent study by the department of immunology and rheumatology at Stanford University in southern California found that adults who run consistently can expect to have 25 per cent less musculoskeletal pain than non-runners when they get older.

“It slows your metabolism”

Brookes warns that “if you want some serious muscle wastage and to reduce your metabolic rate, then keep running.” Brewer says this suggestion is “ludicrous”. Running at a steady pace is known to increase metabolism by 10 to 15 times compared to rest, and this increase continues long after you stop running. “Running will develop muscle tone and strength in the legs and trunk, and to suggest it causes muscle wastage is a complete fallacy,“ says Brewer. “Most people have enough stores of body fat to provide energy for around 40 consecutive marathons, so even the occasional long run is unlikely to have any serious impact on the muscles, since the body only burns protein (muscle) as a last-resort energy supply.”

“It produces more body fat”

“The more you run, the more your body prepares itself for your next run,” Brookes states. “You will actually start to hold on to more fat, so you can run for longer next time.” Louise Sutton, head of the Carnegie Centre for Sports Performance And Wellbeing at Leeds Metropolitan University says there is no evidence whatsoever to support this claim. “Running is among the best ways to burn kilojoules, it burns fat along with the body’s other store of energy– carbohydrate,” she says. “Run regularly and you will burn more fat and lose weight. There’s no escaping this basic scientific fact.”

“It’s boring and time consuming”

Like any other activity, running does become increasingly time consuming as you raise your goals. “There are no short cuts if you want to get fitter,” says Dearbhla McCullough, a sports psychologist at Roehampton University. “People like to sell the idea there’s a magic bullet for fitness. There’s not. It takes time and effort.” And boring? Try telling that to the millions who run regularly!

“It causes cardiac distress and heart attacks”

“Your body simply isn’t designed to run long distances and the stresses you put your heart under during this time can set you up for a heart attack,” Brookes claims. But Brewer states all scientific evidence shows that regular aerobic exercise, such as running, can greatly decrease the risk of a heart attack. “Our bodies are indeed designed to run and the heart is designed to work at high intensities for long periods of time,” he says. “Evidence clearly suggests that the risk of heart attacks among people who run is far less than in those who don’t run or exercise.”

“Fat burning slows down”

“Runners have to run further and further to get the same calorie expenditure they achieved when they first started,” Brookes says. But Brewer says that, once again, this is a totally false statement. “The body needs energy to cover any distance while running, and to suggest otherwise defies the basic laws of physics,” he says. Sutton also says that running, like any other activity that raises the heart rate, will always consistently burn calories. “Science has also shown that regular running leads to physiological adaptations that mean a runner’s body becomes more efficient,” she says. “Runners instinctively learn to use fat first, so that they spare valuable carbohydrate stores.”