Active/Very Active, Moderate, and Light Minutes

[hviola]

OK, I've read all the info on how "Active/Very Active" minutes are counted based on estimated METs but am trying to get a better idea what "moderate" and "light" mean as well.

With the fact that everybody's aerobic exertion rates, heart rates, METs, etc. would be different, I'm wondering if someone can help on some very general sense...

What separates or defines "Moderate" vs "Light" minutes. Are these MET guesstimates too? If so, how should you look at them?

I seem to get VAMs only in what I would guess to be higher than my target heart rate - that is, at very high levels of exertion, like super high. My target HR zone is 90-150 roughly. From observing when I do/do not get VAMs, I think it's over my target zone. I've used a lot of HR monitors in the past and have a pretty good feel for this.

So, does anybody have a reasonable idea of what level of aerobic or HR activity could be guessed based on "moderate" minutes? VAMs seem to be on the high end of what would be aerobic HR levels, so is "moderate" roughly anywhere in my target zone of 90-150?

I don't much care about "Light" as I view that as just general life mostly. I'm just interested in learning how activity "Moderate" is indicating.

[Colinm39]

@hviolaI found I had to establish the calorie level Fitbit determines which of the three Active Minutes categories it calculates. The Fitbit calculates that every 60 seconds. Using a simple manual recording as in the image I kept adjusting the calories until the colours changed. Once established I found I needed to walk very briskly @ 135+ steps/minutes or 4.2+ mph (6.75kmh). 75-80% maxHR. My BMR is 1580. At that speed you will find the stride used always moves between walking and running. I found it difficult to get 100% of VAM even though the steps were consistent. The Fitbit Ultra was centre waist mounted.

This graph shows the VAM and every spike of 7 calories and higher. I received 26 minutes of VAM from 53 minutes. If I were to overwrite the activity with the 373 calories I would receive 100% VAM. Doing that the calories/minute is 7.03 average and based on the consistent step count that is what should happen.

[Heybales]

Here's METS walking and running, and with the Fitbit zone dividers by METS, just need your workout to feel the same as whatever speed gives you the desired METS.

Option for Gross is what HRM or Fitbit would be giving BTW.

And studies have shown that formula for the indicated walking and running speeds is within 4% of measured - much better than a HRM.

http://www.exrx.net/Calculators/WalkRunMETs.html

And that's a huge target zone you got there. 90 has been found for men and women to be the point aerobic exercise actually begins, so that would be well under a recovery training zone.

What are your zones based on for goal?

www.calculatenow.biz/sport/heart.php?

[slysam]

Hi, METS (Metabolic Equivalent of Task) don't vary for everyone by heart rate, etc. That is why they are used for general comparison and why many online activity calculators use METS for their calorie burn estimates. There are some activities where it is considered more accurate to use METS than a heart rate monitor estimate (i.e. non exercise and non-aerobic activities). When a calculator uses METS to estimate calorie burn it does factor in weight and maybe possibly other individual differences (though my impression is a lot of online calculators seem to assume everyone is male and adjust just for weight). But for everyone, sitting still is 1 MET, Sleeping is a little less than 1 MET (was it .8 MET), and walking 4 mph is 5 METs. For just about any walking, running, cycling speed their is an established MET value and that is the same for everyone--but the calorie burn will vary depending on your specifics and how tiring it seems will vary by how fit you are. I don't fully understand METs and think the online calculators that are based on METs (like Fitbit's activity database) seem to have overly simplified options for some activities. I.E. Circuit training has an assigned MET value for everyone--but depending on the specific exercises chosen and how vigorously the exerciser works it probably should be different for different people. I am not sure if that is an issue with METs (using averages) or if that is just because for such charts to be useful they have to simplify things. I think it was Colin that had posted a really good online MET chart, but I didn't save the bookmark.

About the difference between moderate and vigorous. I agree this will vary by the person in perceived exertion. I think on the old forum Fitbit had said the activity minutes were meant to be based on Center for Disease Control guidelines for activity for adults (I think between 18 and 60? in age). On the CDC site they give some general advice about what they consider to be at moderate vs vigorous level. Their guideline is for a certain amount of moderate minutes a day, a certain amount of vigorous or an equivalent combination of the two intensity classes. They list aerobic activity examples of the two intensity classes. They don't recommend a specific number of 'light activity" as they stated it doesn't contribute enough to aerobic fitness.  I was surprised they recommend strength training at least twice a day but don't seem to include it in the intensity minutes (which seems to be for aerobic exercise and other suffiently intense lifestyle activity): http://www.cdc.gov/physicalactivity/everyone/guidelines/adults.html

HRM zones are a different matter. If you can easily get above your maximum heart rate then your device isn't set correctly for your body. The maximum should be the most your heart is capable of beating under normal circumstances (i.e. not a panic fueled crisis). And you should really only see it briefly if doing all out effort. The common formulas estimate high or low for a lot of people. 

[slysam]

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@Heybales wrote:

And that's a huge target zone you got there. 90 has been found for men and women to be the point aerobic exercise actually begins, so that would be well under a recovery training zone.

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I need to look at that link. Is that such a large range? I guess I don't know the intensity it reflects whether that is her moderate aerobic zone or the whole range (some hrm's give 5 zones or more). My hrm app, Digifit gives me a range of 80-160. But not all that is aerobic. 80 is the lower floor for zone 1 (of 5) described as "warm-up/cool-down, easy". And 160 is the upper ceiling on zone 5 "VO2Max, maximum effort". My zone 3, "aerobic/endurance" range is estimated at 112 -128. I have tinkered with my settings a bit and used the optional fitness assessments in my app and this does usually seem to match my perceived exertion for aerobic activity. 

[slysam]

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@hviola wrote:

I seem to get VAMs only in what I would guess to be higher than my target heart rate - that is, at very high levels of exertion, like super high. My target HR zone is 90-150 roughly. From observing when I do/do not get VAMs, I think it's over my target zone. I've used a lot of HR monitors in the past and have a pretty good feel for this.

So, does anybody have a reasonable idea of what level of aerobic or HR activity could be guessed based on "moderate" minutes? VAMs seem to be on the high end of what would be aerobic HR levels, so is "moderate" roughly anywhere in my target zone of 90-150?

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That sounds like a big range for moderate activity, though similar for mine per my heart rate monitor for the entire range. How many zones does your HRM report and what zones are 90-150? As mentioned in my other post in response to HeyBales observation, my HRM has 5 zones. I would think zone 2 (fat burning) and the lower end of zone 3 (aerobic/endurance) is usually "moderately active" for me. The upper end of zone 3 and any of the higher zones--vigorous.

But logging my HRM calorie burn, it doesn't always get it right in intensity level. It actually does okay for steady state aerobic activity. But when you start getting intervals of zone 5, or stop/start activities like weight lifting it does tend to class it as "moderate activity". I think most HRM's use "Average heart rate" and activities with intervals and breaks will have a lower average heart rate if you recover quickly from the work intervals and may give a higher average if you don't recover quickly. That is part of where METs can actually be  more accurate. I agree it is frustrating when you do a very vigorous workout, log your HRM calorie burn and see it credited less intense than brisk walking. Just keep in mind, all calorie burns are estimates and sometimes the HRM isn't as good at estimating an activity as we might expect. So I imagine you probably do see some weird variations on active minutes with HRM logged activity.

[Heybales]

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@slysam wrote:

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I need to look at that link. Is that such a large range? I guess I don't know the intensity it reflects whether that is her moderate aerobic zone or the whole range (some hrm's give 5 zones or more). My hrm app, Digifit gives me a range of 80-160. But not all that is aerobic. 80 is the lower floor for zone 1 (of 5) described as "warm-up/cool-down, easy". And 160 is the upper ceiling on zone 5 "VO2Max, maximum effort". My zone 3, "aerobic/endurance" range is estimated at 112 -128. I have tinkered with my settings a bit and used the optional fitness assessments in my app and this does usually seem to match my perceived exertion for aerobic activity. 

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That is a huge range, well below normal Active Recovery HR zone, which is fine for warm-up/cool-down, and probably not that high.

I'm betting her zone is based on a Polar HRM that on the cheaper ones has a single line, between fat-burning (mis-applied) and fitness zones. And her description sounds like the lower level.

I guess I didn't consider that might be the whole range as you mentioned on yours.

Though, perhaps she has diesel heart like yours and top of upper range really is 150. I have Honda heart, my LT threshold is 176 to HRmax of 194. So my lower zone to start getting more than just a warmup is 123.

I'm really surprised the Digifit goes down to 80 as start of anything.

The section in here on Flex HR has good description and study references, average is 90.

That's the point where a linear relationship between HR and oxygen use and therefore calorie burn start, below that point there is no good relationship, and that's where the Fitbit comes in great.

http://dapa-toolkit.mrc.ac.uk/physical-activity-assessment/methods/heart-rate-monitoring/index.html