Activity Minutes vs. Calories Burned

[RodneyJ]

Hi! I use a Fitbit Versa 4 and enjoy it. I'm really interested in Calories Burned and Activity Minutes on the app and the watch. However, I noticed during my walks to school(taking my daughter to school), the walks don't show up at all in "Active" Minutes. In fact, I could spend 2 hours walking and it wouldn't show any Active Minutes recorded...because my heart rate really wouldn't be too elevated. My resting heart rate is 54.....and when I walk, it's up to 100. But my Active Minutes don't start recording until my heart rate hits 105+. It seems like, although it's nice to look at Active Minutes on the app/watch, calories burned seem to be a better indicator of total activity. Because, as I'm walking, my calorie burn is increasing.....even though my heart rate isn't up over 105. But my heart rate has almost doubled from my resting heart rate while I'm walking to school. I noticed the same thing with weight training - my heart rate, overall, is elevated......but it only records Active Minutes when it ramps up past 105 - and most of the time, it's not over 105 during weight training. Isn't overall Calorie Burn a better indicator of activity? I mean, I love the Active Minutes number......but it doesn't seem to "count" everything I do during a typical day......whereas the Calorie count seems to count everything due to the heart rate being higher at certain times(even when it doesn't reach that 105 threshold for me). Do I have this right? Or am I totally wrong with this approach?

[LZeeW]

Hello @RodneyJ and welcome to the Community.  A little clarification.  Your Versa 4 awards Active Zone Minutes, not Active Minutes.  Active Zone Minutes are heart rate based and use your resting heart rate in the equation.  Your heart rate zones are divided into Moderate, Vigorous, and Peak.  You get 1x the number of minutes in the moderate zone and 2x the number of minutes in the vigorous/peak zones.  Fitbit uses CDC recommendations.  The current recommendations are for 150 minutes/wk of moderate aerobic activity or 75/wk minutes of vigorous aerobic activity or a combination of the two.  It also recommends strength training two days a week.  Fitbit's Active Zone Minutes help you meet these activity recommendations.

The CDC uses brisk walking as an example of a moderate activity.  Your weight training is important.  I think it's very hard for anyone to get Active Zone Minutes lifting weights.

CDC: How much physical activity do adults need? 

CDC: Benefits of Physical Activity 

[JohnnyRow]

Adding to what @LZeeW correctly stated, yes calories burned includes everything, but that is not the intent of zone minutes, or active zone minutes (not activity minutes as you were calling them).  The purpose of active zone minutes is to measure the time when your activity is at a higher intensity, which has added health benefits.  If you are hitting a heart rate of 100 when walking, you would probably find that it would reach the required 105+ with little extra effort (probably not when walking your daughter to school), to earn yourself some zone minutes and added health benefits, although of course the difference between 100 and 105 heart rate is not really a magic cut-off point with huge health benefits, but just seeing the numbers can be a motivation.

[RodneyJ]

I guess here's what I'm trying to figure out:

I've been looking at two main numbers on my Fitbit Versa 4........the first is Calories Burned per day......and the second is Active Zone Minutes. It seems to me, if I'm not mistaken, Calories Burned measures pretty much everything. So, if I'm walking my daughter to school...lifting weights....running....cycling....whatever, it measures all of it. If my heart rate is higher, the Calorie Burn is higher per minute. As the intensity goes up - like when you are in "Peak" Activity Zone - the calorie burn actually goes higher than if you're in "Moderate" or "Vigorous" Activity Zones. If I'm walking my daughter to school(30 minutes each way), the Calorie Burn also counts all of that movement even if my heart rate is below 105. So, at the end of the day, the Calorie Burn number counts everything I've done. So......that's great.

But......it seems to me(if I'm not mistaken)......that if I'm concentrating more on Active Zone Minutes.....then my fitness level goes up. So, instead of just looking at Calories Burned, I'm really just concentrating on Active Zone Minutes per day........so trying to increase that number per day is doing "more" to help my fitness level. I'm trying to figure out if that is truly the case. I've had days where my Active Zone Minutes were 150(for the day), but my Calorie Burn was below 4,000 for the day(mostly because I was sitting or doing low heart rate activities the rest of the day). In turn, I've had days where I've burned 5,000+ calories.....but my Active Zone Minutes were below 40......because I was doing a ton of walking(up to 45,000 steps for the day.....at a heart rate lower than 105 for most of it). So......my question becomes......which is more important? The Calorie Burn or the Active Zone Minutes? Right now, I'm averaging 120 Active Zone Minutes per day. I'd like to increase it. But I'm also looking at Calories Burned, thinking maybe that catch-all number is the real one I should be looking at, instead of Active Zone Minutes. I read somewhere - possibly on this forum - that to increase fitness(my primary goal), you should look at the Active Zone number. But I'm wondering if this Calories Burned number is more worthwhile - trying to increase that number, even if some of my Active Zone days are pretty small.

[JohnnyRow]

I hope this amount of exercise has not been just a recent increase, but something you have been building up to for quite a long time. Otherwise if this is just a recent increase so your body is not used to it, I would worry you could be headed for an overuse injury, and hope you are getting your body plenty of rest.

Assuming this has been an on-going routine, this gives me a totally different viewpoint of your situation.  From your first post, I got the idea you were getting barely any zone minutes.  But if you are averaging 120 AZM per day and walking up to 45,000 steps a day, you're way beyond the level of trying to maintain a basic fitness level.  The CDC and American Heart Assn recommend 150 AZM per week and you are nearly doing that in a day, so I'm not sure I'm in a position to be giving you any advice other than not to overdue it to the point of getting injured.

[RodneyJ]

Yes, I understand - thank you so much. No, this isn't new to me....I've spent quite a long time at this activity level....after a very long build-up. Sundays are normally in the 270+ Activity Zone Minutes range......and I normally average around 120+ per day on the other days. I enjoy using my Fitbit, but I'm really trying to concentrate on just that one goal(for simplification)....either Calories Burned or Activity Zone Minutes. I guess....from what I've been reading on other posts across the Net....AZM is really the way to go for overall fitness. And I guess, reading back on my own post, that was my real question.......what was more effective for fitness....AZM or Calories Burned. Others, like myself, have noted that things like walking are rarely recorded in AZM because of the heart rate. One runner noted that when she switched from running to walking, her Calorie Burn stayed the same....even though her AZM was next to nothing.....and she felt her overall fitness had actually decreased(even though Calories Burned remain constant). That was a concern of mine too....what would happen if I just concentrated on Calories Burned? It's a catch-all.....but, like her, I found my AZM could be minimal and my count would still be elevated because of all the steps. In turn, I felt less fit. So, I was just pondering this subject of Calories Burned vs. Active Zone Minutes. Thank you so so much for your help - it is really appreciated - thank you!!

[JohnnyRow]

I guess I would say at most average levels, intensity, with adequate rest, is more important for building fitness, thus the value of HIIT or running or swimming intervals, assuming high intensity is not done consecutive days.  But at upper athletic levels, they also do huge amount of lower intensity workouts, witness the incredible mileage put in by top runners and swimmers.

So I have no clear answer, but interesting question.

[JohnnyRow]

Thinking it over some more, I think at that level, you might have to start out by defining "fitness" for yourself.  For many people it might mean reducing risk of cardiovascular events to a reasonable level.  But to some it might just mean increasing your VO2 max as much as possible as a measure of cardio fitness, while this might mean ignoring any weight lifting or body-building, exemplified by world-class marathoners, perhaps the epitome of "fitness" but probably not the look most of us aspire to.  Or at one time many years ago, fitness to me just meant my time in recreational 5K or 10K races.  For people spending that much time exercising, perhaps it should broaden into looking at total life fitness to include all aspects of one's life.

[YachatsMike]

The Fitbit calorie counter counts Basal Metabolism Calories, too.  Those are the calories burned just to keep you heart beating, your body warm, your lungs pumping and your gut processing food.  My BMR is about 72 Calories / Hour.