We're always being told to do more exercise and for many of us, the news we don't have to work too hard — and get all hot, sweaty, and breathless while doing it — has been a significant selling point.
After all, exercising at a moderate intensity, where there's just a slight but noticeable increase in your breathing and heart rate, meets minimum recommended exercise targets.
Something as doable as brisk walking fits the bill, and if you can clock up 30 minutes on most days of the week, you can cut your risk of heart disease significantly — perhaps even halve it.
But is pushing yourself harder going to bring extra benefits?
"Absolutely," says Jeff Coombes from the School of Human Movement and Nutrition Studies at the University of Queensland.
While higher-intensity exercise isn't essential, Professor Coombes says it will definitely improve your level of fitness — the efficiency with which your heart and lungs work to get oxygen delivered to and used by your muscles.
The research is clear: the fitter you are, the less likely it is you will die of pretty much any health condition you can name, he says.
"With some limitations, there's good evidence the more [intense exercise] you do, the better off you'll be," Professor Coombes says.
More bang for your exercise buck
The reason moderate-intensity exercise is emphasised by public health experts is because half of us do little or no exercise at all.
If you're one of these people, switching from being inactive to exercising moderately is great bang for your buck, Professor Coombes says.
You'll significantly cut your risk of heart disease, Australia's biggest killer, for a relatively small increase in effort.
You also take a significant step towards warding off diabetes, stroke and probably a host of other conditions, too.
While you can further reduce your risk of heart disease, stroke, and diabetes by working harder while exercising, the reward for your extra effort is comparatively smaller.
It's feared the advice to go hard may actually scare those who are inactive off exercising all together.
Using exercise to reverse disease
Exactly how much healthier you'll be for your extra effort might depend on the disease you're trying to prevent, Professor Coombes says.
For instance, if you have diabetes and want to improve or reverse your symptoms, then exercising at a higher threshold of intensity might be critical.
"We know moderate-intensity exercise is very good for preventing the onset of diabetes but for people who already have it, it seems moderate intensity might not be enough to reverse it or improve the symptoms," he says.
Risk vs benefit
All exercise has safety risks and these increase when you push yourself harder.
However, the odds of a potentially fatal event like a heart attack or stroke are still very low, even when you exercise hard, Professor Coombes says.
"We're talking about one [adverse event] in tens of thousands of hours of exercising," he says.
"The risk is very minimal compared to the benefits."
Professor Coombes stresses the importance of being assessed for factors that increase the odds of heart attacks or strokes from exercise prior to starting an exercise program.
Treating those risk factors usually means exercise is still possible, but it may have to be tailored to your needs.
However, some people's health conditions may mean they should stick to lower-intensity exercise.
The greatest area of increased risk from exercising harder is probably muscle or joint problems, Professor Coombes says.
"You need to be careful. Listen to your body, don't do too much too soon," he says.
Getting started with exercise intensity
If you want to try working at higher intensity to boost fitness, Professor Coombes suggests aiming at a level where your heart rate will reach 85 to 95 per cent of its maximum beats per minute.
You should be too breathless to say more than a few words.
In comparison, moderate-intensity exercise is at about 60 to 65 per cent of your maximum heart rate; you should be too breathless to sing but you should still be able to talk.
While working harder than 95 per cent of your maximum heart rate may have extra benefits, there's less evidence to support its safety, Professor Coombes says.
He says the best results come from interval training, where you switch from short bursts at higher intensity to short bursts at moderate intensity.
"You'll end up keeping your heart rate higher for longer than if you try and go hard continuously," he says
Is vigorous exercise for you?
If the very idea of huffing and puffing puts you off exercising, don't feel compelled to do it, Professor Coombes says.
Pushing yourself to do a form of exercise you don't enjoy is a great way to turn yourself off exercise in general.
Instead, finding something you'll stick at is more important.
However, if you're looking for a way to add some variety to your exercise routine and get some extra health benefits, high-intensity interval training is definitely worth a try, he says.
Article from ABC Life