Exercise myths

PUBLISHED : Monday, 17 February, 2003, 12:00am
UPDATED : Monday, 17 February, 2003, 12:00am

The amount of information regarding our health and fitness is astounding. While most of these sources are reputable, some have created exercise myths and misconceptions about the role and value physical activity plays in our lives. The following are some of the more common myths as well as explanations as to why they aren't true.

Women who lift weights will become too muscular

It's physiologically impossible for most women to naturally (without steroids) gain the same muscle mass as men, because they lack the necessary amount of testosterone. In fact, because women do have less bone and muscle than men, it's more important for them to look after what they've got. Studies have shown that by strength training twice a week, women can benefit from increases in lean muscle mass (the stuff that revs up the metabolism), bone density (decreasing the chances of osteoporosis), and muscle strength and balance (important for mobility later in life).

Using light weights on your arms and legs while doing cardiovascular activity can increase fitness benefits

People often wrap weights around their ankles and carry small hand weights while exercising. All this does is put extra strain on your joints, tendons and ligaments. In fact, you don't actually burn more calories because it slows you down. It doesn't make you stronger or build more muscle either.

Spot reducing is possible

Some people believe that to lose fat off their stomachs or hips, they have to exercise that one area. It doesn't work that way. Abdominal and hip exercises may help tone and strengthen these muscles, but they're still underneath the layer of fat causing that area to look flabby. Only by losing weight can you get rid of the excess fat. Where we deposit our fat is genetic.

If you exercise, you can eat whatever you want

While a lovely thought, but it's not always the case. Exercising doesn't actually burn as many calories as you may think. Walking briskly or jogging for a couple of kilometres burns about 100 calories, while sitting for the same amount of time uses 50 to 60 calories. You don't burn that many calories after you stop. For the first minute or two after you stop exercising, calorie expenditure is higher but 40 minutes post-exercise, it's back to where you started. The way it really works is the more you exercise the fitter you get, so you can burn more calories because you walk briskly or run for 8km instead of 2km. So now you can burn 500 calories instead of 100. The better shape you're in, the more your muscles adapt to using the enzymes that oxidise fat. The muscles in less fit people will burn more carbohydrate (glycogen) than fat.

Exercise has to hurt in order for it to benefit

Many people still believe they have to work out really hard in order to get any benefit from exercising. Not true. In fact, moderate-intensity exercise has much the same benefits as high-intensity exercise. The key is to make sure any type of activity you do is at least at a moderate intensity or the equivalent to walking at a pace of 5-6km per hour. High-intensity exercise has the advantage of saving time: it takes less time to burn the same number of calories. For example, jogging for 20 minutes roughly equals 40-45 minutes of brisk walking.

Finally, I don't have time to exercise

You have all the time there is; it's just a matter of priority. If you don't make the time now, then your health will make you take the time later. Health problems such as heart disease, diabetes or osteoporosis can occur as a result of inactivity.