We need to do how many hours of “exercise” for optimum health?

This article about Australian researchers who have called into question the World Health Organizations activity recommendations, generated at least two comments containing the F-word on our FB page yesterday (and I don’t mean “Feminist).

According to these researchers, “People need to do five times the exercise recommended by the World Health Organization (WHO) to stay healthy.” The report goes on to say:

Researchers from the University of Queensland studied the link between physical activity and chronic health conditions including breast and bowel cancer, diabetes, heart disease and stroke.

They found exercise levels recommended by the WHO needed to be much higher to increase resistance.

The numbers they came up with are actually quite astonishing. If you want to reduce the risk of chronic disease, here’s what’s needed:

  • Run between six and eight hours per week
  • Ride for seven hours per week
  • Swim for eight hours per week
  • Walk briskly for 15-20 hours per week

That’s a lot of hours of activity. I’m a pretty active person, walking close to two hours a day Monday to Friday, swimming for 90 minutes a couple of times a week when I’m on task with my routine, and running for at least a couple of hours a week. But if you look at the suggestions, I’m not doing any one thing nearly enough.

Now one thing worth pointing out, as one person who commented on the FB thread said, is that it’s not as if the WHO guidelines give no benefit. It’s more that these new findings point us in the direction of maximum benefit.

But five times more than what the WHO recommends is an astonishing increase in the received view.  By the WHO standards, a couple of hours a week of running or three hours of walking will do you just fine.

I am not a bioethicist, but I do think that we need to think critically about these findings. For one thing, while reducing our risk of chronic diseases and conditions is a desirable goal, so is general physical fitness. And though I have just read a report of the study and not the study itself, it would also be useful to know the health benefits of different levels of activity between the WHO recommendations and the recommendations of this research group.

Even the WHO guidelines say that you can achieve further gains with more activity:

For additional health benefits, adults should increase their moderate-intensity aerobic physical activity to 300 minutes per week, or engage in 150 minutes of vigorous-intensity aerobic physical activity per week, or an equivalent combination of moderate- and vigorous-intensity activity.

They also encourage resistance training, about which the new study (or at least this report on it) is silent. From the WHO guidelines:

Muscle-strengthening activities should be done involving major muscle groups on 2 or more days a week.

So before people start saying “WTF,” we might want to examine more carefully what impact this new study should have on people’s actual activity level or the activities they choose.

Do you have any thoughts on these findings and will they in any way influence your level of physical activity?



2 thoughts on “We need to do how many hours of “exercise” for optimum health?

  1. The Guardian newspaper had a bit more info yesterday:
    The WHO advice is based on exercise using 600 METs (= 75 mins of jogging or 150 mins of walking a week). This was found to give a 2% reduction in the likelihood of getting diabetes (and similar levels for CV disease etc.).
    The new study recommends 3000-4000 METs, so over 12 hours of walking a week or more than 6 hours of jogging at the low end of the range. This gives an additional 19 % reduction in likelihood for the 5 conditions. But above 4000 METs there was no significant additional benefit.

    So it’s a lot of exercise: I cycle to work most days and ride with a club on Sundays and that adds up to about 10 hours a week in summer (perhaps 6 hours in winter – but I walk more then). Most people think I’m a fitness fanatic, especially when I throw in a couple of swims a week and daily yoga/pilates (this is mainly to keep my old joints going and I wouldn’t really count it as aerobic exercise). But clearly, I’m only doing about the right amount.

    I can’t see that increasing the amounts in the WHO guidelines will have any positive effect. People who meet the current guidelines probably already do more if they can (e.g. once they get into the routine, get fit etc. it gets easier) but those who don’t are likely to think ‘sod it’ and do nothing.

  2. I would have thought it would be 1 of those physical activities, not all in 1 wk.

    I haven’t paid attention to WHO guidelines or any physical activity guideline. I think I know how much cycling and walking I need. Certainly in the winter, it goes down..

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