How much exercise should you really be doing? 30 minutes a day might not be enough

WE ALL know that 30-minutes of exercise on most days of the week is good for us, but a new study questions whether the bar has been set high enough.

When it comes to preventing heart failure, the more exercise, the better according to a new analysis published in the journal Circulation. How much more? Researchers, who followed over 370,000 people for an average of 15 years, suggest as much as two to four times the 30 minutes per day magic number.

Current Australian physical activity guidelines (updated last year) recommend 150-300 minutes of ‘moderate’ intensity physical activity or 75-150 minutes of ‘vigorous’ a week. That could mean a brisk walk for 30 minutes a day, five days a week; a high-intensity spin class one day for 45 minutes, plus a half-hour jog another day; or some other combination of moderate and vigorous activity.

This amount is not only double the 150 minutes previously advised in 1999, it’s also double the amount recommended in international exercise guidelines.

One way to gauge moderate activity is with the “talk test” — exercising at a pace where you are able to comfortably talk but not sing (eg: brisk walking, digging in the garden). Vigorous intensity activity requires more effort and makes you breathe harder and faster.

WHAT ABOUT WEIGHT LOSS?

To prevent unhealthy weight gain, the guidelines recommend adults increase to 300 minutes (five hours) or 60 minutes of moderate intensity activity on most days of the week.

Spending 300 minutes a week sweating it out takes dedication, and it can be hard to work in an hour each day devoted only to fitness, however it’s a target designed to prevent many of us from gaining weight, which also helps to prevent diabetes, cardiovascular disease and several cancers as well.

SHORT ON TIME? GO HARDER

The latest trend in exercise, known as high-intensity interval training, or HIIT, is a form of cardiovascular exercise that alternates short burst of exercise (near the peak of a person’s ability), followed by a recovery period of easy activity. This form of cardio training is different from traditional cardio workouts that involve working for a sustained period of time, without rest, such as walking, jogging, running, cycling, or using cardio machines. While both forms of cardio improve fitness, interval training is now being studied as a treatment that is more effective at improving fitness and greater fat loss in a very short amount of time.

However experts warn that high-intensity exercise is not appropriate for everyone and a medical clearance is required before starting. You need to have a better than average level of fitness to do this type of training safely at the intensity required. What’s more, vigorous exercise can have traumatic effects on the joints (eg: hips and knees) especially as you age.

BOTTOM LINE

Doing any physical activity is better than doing none.

“The real risk is the amount of time we spend sitting and we need to look more closely at total energy expenditure throughout the day” adds Stanton.

The latest ABS survey reveals that just under 60 per cent of Australian adults did less than the recommended 30 minutes of moderate intensity physical activity per day.

“The biggest health gains will be made by getting people from doing nothing to do a moderate amount of physical activity” says lead researcher at the Institute of Sport, Exercise and Active Living, Professor David Bishop.

So if you currently do no physical activity, it’s never too late to start. Start by doing some, and gradually build up to the recommended amount.

“If adults meet physical activity guidelines evidence suggest this could result in reduced risk of all cause mortality by 30 per cent, cardiovascular disease by 35 per cent, breast cancer by 20 per cent, colon cancer by 30 per cent, type 2 diabetes by 42 per cent and depression by 30 per cent” says Trevor Shilton, adjunct Professor and director, cardiovascular health at the National Heart Foundation.

Low-intensity exercise (eg: walking) is great for beginners, while exercising at higher intensities helps you get fitter and burn more calories. It’s also recommended to avoid prolonged periods of sitting and to do muscle strengthening activities at least two days a week.

But whatever you do, move more, and do so regularly.