Myth: "No pain, no gain."
The old ‘exercise as punishment’ philosophy, that it has to hurt to do you good, has just about disappeared from exercise lore, though for some people, puffing, sweating or messing up their hairdo constitutes pain. So, does higher-intensity exercise have any advantages over lower-intensity?
In terms of basic health benefits, such as living a longer life free from disability caused by disease, just meeting the minimum requirements of National Physical Activity Guidelines for Australians will provide many health benefits. However, vigorous exercise can provide extra protection against heart disease. It can also help with overall fitness and calorie burning.
Exercise shouldn’t hurt, but exerting yourself a little can improve your fitness.
Myth: "Low-intensity exercise is better for fat burning."
The idea is that if you exercise at low intensity, around 50 to 60% of your maximum heart rate, you burn more fat than if you exercise at a higher heart rate, like the 70 to 85% recommended for improving fitness. That would be great news for walkers: as long as you’re walking fast enough that you can talk, but not sing, you’re getting more out of it than the red-faced, sweaty joggers who huff and puff past you.
Sadly, not entirely true. Yes, you burn more fat as a percentage of the total energy you burn when exercising at low intensity — it accounts for almost all the fuel your body uses. But you burn more actual fat per minute, and a lot more total calories, at higher intensities.
The advantage of low-intensity exercise, especially for people who aren’t terribly fit, is that it’s less tiring and puts less strain on the body, so you can exercise for a longer period of time. In the end, it’s the total calories burnt that count — so for maximum weight loss you can either get puffing or just keep going for longer.
Low-intensity exercise is great for beginners, while exercising at higher intensities helps you get fitter and burn more total energy in a given amount of time.
Myth: "You should stretch before exercising."
While it’s important to warm up before exercise, especially if you’ve just got out of bed or are about to undertake strenuous exercise, there’s no good evidence that ‘stretching’ does much good.
By stretching, they mean doing static stretches to pull at particular muscle and ligament groups, like hamstrings, calf muscles, Achilles tendons and so on. Warming up, on the other hand, is doing the basic moves of whatever it is you’re about to do (running, swimming, cycling, playing soccer) at a low intensity. Proponents of stretching say it prevents injuries and muscle soreness and improve performance. However, reviews of many studies have found there’s no beneficial effect on reducing the chances of injury and soreness, and there are contradictory findings on performance — some find it helps, some find it hinders, some find no effect.
Stretching is still useful, to help maintain or increase flexibility, and can improve performance in the long term, so do it another time — while you’re watching TV, say.
Stretching before exercise doesn’t appear to help reduce muscle soreness or risk of injury.