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More physical activity is required
  • Our findings have several important implications. They suggest that total physical activity needs to be several times higher than the current recommended minimum level of 600 MET minutes/week to achieve larger reductions in risks of breast cancer, colon cancer, diabetes, ischemic heart disease, and ischemic stroke. Focusing on a particular domain such as leisure time physical activity, which represents only a small fraction of total activity, as was done by most studies, restricts the scope of applicability of the findings in the real world by limiting the opportunity of increasing activity in different domains in daily life (such as being more physically active at work, engaging more in domestic activities such as housework and gardening, and/or engaging in active transportation such as walking and cycling). Taking into account all domains of physical activity increases opportunities for promoting physical activity. Further work with studies with more detailed quantification of total physical activity is warranted to provide more precise estimates for different levels of physical activity. Finally, the methodological innovation of this study could be applicable to other systematic reviews (in different specialties) meta-analyzing studies with variation in categorizations of exposure.

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    http://www.bmj.com/content/354/bmj.i3857

  • 7 Replies sorted by
  • I wish that folks would not show plots where the scale is blown out of proportion. On a 0-1 scale this doesn't look so dramatic.

  • Looking at that graph, it makes one feel that unless you are doing at least around 4000 MET, you may as well not bother exercising at all. Take a look:if you exercise like mad, you may cut the risk of some diseases like Diabetes and heart disease by 25% which is not a huge amount - and other diseases even less... breast cancer, barely 5% - at 4000 MET. Do you realize how much 4000 MET is?? It's enormous. I jog 4 times a week, 40 minutes each time for a total of 160 minutes a week and that translates into around 1200 MET. Now take a look at that graph, where 1200 MET buys me almost nothing for diabetes, or colon cancer. I get about 10% risk reduction for stroke and heart disease. That's not a lot of reduction at all. All that exercise and almost no reduction of major diseases. Unless I want to spend all my time exercising... what's the point of living then? I don't enjoy exercising and I don't live to exercise. These graphs make me want to quit altogether. May as well enjoy life without torturing myself with exercise that's never enough.

  • I'll drink to that. ;-)

  • In reality you must add few things to it. If you spend so much effort and is amateur it also means much bigger chances of knee and other legs issues (not 10-20%), possible issues with muscles and ligaments.
    I am excluding here possible issues with your head if you run or bike a lot.

  • Thinking 4000 MET is a lot, says much about our lifestyles and confirms the point made in the article ("Focusing on a particular domain such as leisure time physical activity, which represents only a small fraction of total activity")

    4000 MET would be practically nothing for somebody working in an active job even 40hr/week; and as the article says, active commuting helps as well. Walk the dogs...

    If dedicated exercise is challenging, try and adjust your lifestyle to compensate. While there are risks associated with exercise, there are other benefits as well.

  • Gosh-I'm such a goner

  • It's a good study and a good wake up call to people that they need to do more than a few hours of exercise per week and then sit the rest of the time.

    3600 MET per week is pretty easy to accomplish. 30 minutes of walking + 30 minutes of vigorous exercise + 60 minutes of non-exercise physical activity (housework, gardening, light physical labor) six days a week would easily add up to 3600 even assuming you sat around doing nothing at all the 7th day.

    You can't belittle a 20-25% reduction in things like heart disease, stroke, or diabetes. These are actually enormous health improvements against leading causes of death. Both on a personal and societal level, these are major, major improvements -- and they are essentially free! Any researcher who invented a new way to get a similar improvement in any one of these diseases would be assured a Nobel Prize in medicine.

    Personally, I find the research inspiring. I love to quantify things like this and know when I'm really getting the right amount of exercise based on good research. I'm not 100% convinced that vigorous exercise can really be boiled down to being equivalent to twice as much low intensity exercise -- I think there's a qualitative difference there -- but it's a good guideline for things like this. Also, there are numerous other proven benefits to getting this amount of physical activity, this study just looked at some top killers.

    (But yeah, don't overdo the running. It can lead to arterial stenosis and breakdown of knee cartilage, which recent research seems to indicate never regenerates in a meaningful way.)