How much physical exercise is enough? Where are you supposed to find time to exercise every day? Do you really need to run / lift weights / climb stairs? These are all common questions, some of which can be answered with some new and exciting (aren’t you excited??) research!
You’re probably most familiar with the current recommendations published from the US Department of Health and Human Services, which suggests 150 minutes per week of moderate physical activity, or 75 minutes of vigorous physical activity per week. This requires somewhere between 15 and 30 minutes of physical activity per day, assuming 5 days a week. Where can you find that kind of time? Check your next coffee break, your next browsing session on Facebook (possibly for articles like this!), or your next episode of Jeopardy. That much time, or less, 5 times a week is what the recommendation suggests.
How much will this physical activity benefit me? (or how I learned to stop writing prelude and tell you why you should care)
A very recent study published in the October 2015 issue of The British Journal of Sports Medicine reviews the relationship between the time spent doing moderate to vigorous physical activity (MVPA) and mortality rates. In it, they use a systematic review and meta-analysis to pool their results.
(They used a what? A systematic review and meta-analysis is a process in scientific literature where a bunch of previous studies, with similar research methods and questions, are merged together (where appropriate) to create a larger selection of people to study. Conducting research this way limits randomness within outcomes — eg. if I wanted to know if pulling your leg twice made you taller, I can be far more certain of my answer if I do this to 10 000 people than to just 10. Any changes (or lack of changes) in my group of just 10 could have nothing to do with me! It might be total chance/luck/or extraneous variable. So systematic reviews and meta-analyses are wonderful birds-eye pictures for how some interventions work.)
In this particular study, the pooled results meant 122 417 participants were examined, all of whom were at least 60 years of age — older adults. The average follow-up time on participants, to gauge mortality rates, was 9.8 years.
The results compare the time individuals spent doing MVPA with those who did not participate in MVPA. They found:
- Low doses of MVPA (less than the recommended amount per week): 22% decrease in mortality rate
- Recommended doses of MVPA: 28% decrease in mortality rate.
- Exceeding recommended doses of MVPA: 35% decrease in mortality rate.
So even just a little bit of MVPA — just doing anything, basically — so long as it is moderate to vigorous intensity, can have a significant effect on mortality rates compared with doing nothing. I guess we really messed up that recommendation of 150 minutes then, right?
Not at all, actually! Look at the continued trend up in benefits as MVPA time increases. At the recommended dose, we continue to see health benefits — a 28% reduction in mortality rate. Going beyond this and engaging in greater than the recommended dosage of physical activity, and the mortality rate becomes 35% lower.
For a single factor (MVPA) to contribute so significantly to reducing mortality rates, it really speaks to the importance of maintaining activity, staying physically fit, and engaging in consistent physical activity. I often say that standing is better than sitting, walking better than standing, jogging better than walking, and running better than jogging. I don’t mean this literally of course, as everyone is their own person with their own unique circumstances, but what I’m speaking to is what this study reflects: even doing just a little bit goes a long way.
So take any of the old adages about physical activity you like: motion is lotion, rest is rust, sitting is the new smoking, etc — this study supports their fundamental message to keep moving.
Questions or comments? Have nagging aches and pains that are preventing you from participating in MVPA? Contact Dr. Gilliard at (905) 634-6000, send him an email firstname.lastname@example.org, or book an appointment at Endorphins Health and Wellness Centre.