If I understand correctly, the activity guidelines recommend 500-1000 MET-minutes of activity per week and leisurely walking is 2.5 METS and brisk walking is 5 METS. Is that correct?
Would 200 minutes of normal walking satisfy the guidelines at a minimal level? This would be 200 * 2.5 = 500 MET-minutes. More, of course, would be better.
Is there a good way without lab equipment to judge whether walking reaches the level of “brisk”? Talking and singing tests seem rather vague. Perhaps heart rate, possibly adjusted for age?
I acknowledge I may be reaching for unwarranted precision. I’m ignoring the resistance training aspect.
The MET-min benchmark is correct and off hand, the MET values listed seem right too.
Leisurely walking would not satisfy the guideline minimums as they are not at high enough intensity for most individuals. Certainly better than nothing, but walking that slowly for an otherwise healthy, able-bodied individual probably isn’t enough to be on par with a slightly faster pace’s with similar volumes.
There are many ways to measure exertion, e.g. RPE, HR, breathing rate, etc. though I don’t think it’s necessary to specifically measure this in most cases (unwarranted precision). RPE also correlates well to HR in these contexts, which can be useful.
Above 65% of maximum HR (220-age) seems relatively easy and therefore a reasonable metric for judging moderate activity, so long as one doesn’t indulge in obsessive checking and unwarranted precision.
I find RPE difficult to apply for aerobic activity, especially if I’m determining moderate activity by asking myself if the activity feels moderate.
Middle paragraph of #3 should read: Above 65% of maximum HR (220-age) seems relatively easy to check and therefore a reasonable metric for judging moderate activity, so long as one doesn’t indulge in obsessive monitoring and unwarranted precision.
I do wonder exactly what maximum HR is supposed to mean, since I can easily get mine to at least the computed max (220-65=155), but it is a popular metric.
As I mentioned, I like that metric since HR is easy to measure and more objective than RPE (searching for aerobic RPE is how I found that graphic). A pulse oximeter seems to work well enough for this purpose.
The increase in heart rate (HR) during physical activity tracks with the increase in cardiac output. Thus, “max HR” is thought to be the upper limit for an increase in cardiac output that cannot be surpassed despite increases in exercise intensity or improvements in fitness.
The origin of the HR Max equation, 220-age, is attributed to a large review on physical activity and heart disease from Fox et al. in the 70’s. Interestingly, the data from the original manuscript’s data did not actually support the “220-age” formula, with the authors saying:
no single line will adequately represent the data on the apparent decline of maximal heart rate with age. The formula maximum heart rate=220–age in years defines a line not far from many of the data points.
Later, a research team reviewed the data from Fox et al. and found that is supported the formula HRmax=215.4 – 0.9147. When combined with additional data sets looking at maximum HR during exercise suggests the formula HRmax= 208- 0.7 (age) is the best fit, though there may be a ~6 beats per minute error here as well.