Versa 2 didn't track my calories burned accurately during my HIIT

[LunaCocobean]

I've just finished a HIIT workout (21 minutes long) and it's recorded as 152 calories burned. Would that seem about right? I was always under the impression HIIT was way more than that? My average heart beat per minute was 133 and 160 max although when I tried to look at my watch it didn't always show the heart rate. In general day to day it often stops tracking the heart rate.

Moderator edit: updated subject for clarity

[EdsonFitbit]

Welcome to the Fitbit Community, @LunaCocobean.

Thank you for the information provided.

I would recommend using 'Interval Workout' to do HIIT. If this exercise is not listed in your Exercise app, please visit this article, open the menu "Can I change or reorder the exercises on my Fitbit device?" and follow the instructions. Once the exercise is added, you'll be able to customize your interval workout settings, where you can set the number of repetitions and how often you want your Fitbit Versa 2 to buzz you to move or rest.

There are some factors can affect your heart-rate reading on your Fitbit device. Please follow these tips to resolve heart-rate tracking issues.

If you have any question, please let us know.

[LunaCocobean]

I didn't use the interval workout for this one because I was following a video and it frequently changes the workout and rest periods and I can't keep stopping to change the watch settings. I have an exercise listed just as workout so I used that.

The day before though I did use the interval workout for a different video (20 minutes) and I burned 122 calories. 

I think both are fairly low for something quite intense.

[rajpopuri0331]

I have a similar issue as well. I do my HIIT watching videos and these videos don’t necessarily have a set intervals. Even if they do, they have a longer break between each round and I cannot really have option to set all these intervals in my app. When I work on a HIIT that typically shows 450-600 cal burn and I do it just like in the video, with the same intensity, interval and reps, it only shows 320 cal burn which is way less than the actual when I use my cell phone to track. 

[Stacee2269]

Honestly it isn’t right I mean no matter where I put my watch or reset it etc HIIT training does not record correctly my avg. hr was 104 doing a 22 min HIIT interval training and apparently I hit avgs of similar or even higher walking my 4 year old to school. I burn more on the school run too apparently.. it’s funny really I can take a leisurely walk every morning and afternoon instead of feeling exhausted from a hard workout and burn more calories (eye roll)  I know I’ve burned more and worked harder than the watch has recorded but it annoys me I don’t get an accurate reading.

[JazzerKE]

Mine recently (the last 3 or 4 months) started reading my heart rate during exercise incorrectly and lower than before, too. I just bought another tracker and it is consistently reading similar to what my Fitbit USED to read, which tells me it is the Fitbit's problem and not a change in my workouts. Pretty frustrating!

[VanMac1253]

Just in the past couple of week, my calorie burns are wildly inaccurate.  On Sunday I went on a 6-mile hike, and it gave me only 380 calories.  When I've done this hike before, it's always 700+ calories.  Also, when I went for my 4.1 mile walk/run this morning, which I do several times a week, it is showing only 295 calories burned, when it normally shows me as burning around 400 calories.  This is hugely important to me since my weekly goals include the total number of calories burned.  I have no idea why this is happening, and for the record when I am tracking my workouts I am using the GPS system and am turning the tracker on my phone as soon as I leave, and stopping it at soon as I get back.  It is also the same route every time.  Why is this happening?