HRM Question

elysetoplin

So I got this HRM for my birthday last week (a Garmin Forerunner 305), and was disappointed to see that the workout I'd been doing a lot lately (30 Day Shred Level 2) was only burning 123 calories (instead of 241 like MFP said...which was mostly weird because my HRM had been pretty close to MFP for everything else. So today I did the same workout, but made a few changes - more reps, 8lb weights instead of 5, and using the 5lb weights for some of the cardio - and my HRM said that I burned 631 calories in the 25 minute video. Could this possibly be right? I don't know what to log for this workout because everything just seems really off now and my HRM seems like it's not that accurate for this workout. Has this happened to anyone else? Does your calorie burn increase a lot from little changes? I'm hesitant to log the 631 calories just in case it's wrong, but I'm not sure what to log instead. Any advice?

funkyspunky871

That does seem odd, but you're doing the shred with 8 pound weights! That's unbelievable. Do you feel like you burned that much? That's the only way I can think of to tell if your HRM was right. If your heart rate was really "up there," then sure. It's possible, I guess.

KZOsMommy

When I do 30 day shred I do not burn much and I use 8lb weights, sounds off to me. It all depends on your weight and such. But to go from 123 to over 600 doing the same work out just adding a bit (only two pounds of weight and a few extra reps) seems like a really big jump to me. I don't know anything about that brand of HRM I use a different brand.

Nelski

That doesn't seem right. 631 calories in only 25 minutes? I would assume that is incorrect and see what happens the next time you do it. Did you look and see if it said your HR was insanely high during the workout? My HRM freaks out sometimes and will say my HR is crazy high or crazy low and I know it's not correct.

jkohan

Did you change the factory settings to your personal info--weight, height, age, max HR, etc? You need to do that to get accurate readings and don't forget to change your weight in your HRM when you lose lbs!

I would try 2 days in a row doing the shred the same way to see if it's accurate or it needs to be returned.

vineas

I have a polar FT60, and sometimes get odd readings from it. With the polar at least, when it's getting odd results it's often the case that these odd readings happen from a poor connection to your body. In mine, the strap needs to be wet when I put it on, and if it doesn't have enough water on it the HR will go offline from time to time, which will end up reading much fewer calories. Also, the strap needs to be washed, and when it's dirty it can do the same thing. It will sometimes go wacky and read some insane HR, but it's only done that a couple of times and haven't figured out what triggers it. Not sure if any of this applies to the Garmin or not, but is something to look at.

nehtaeh

That does seem off. My HRM told me I burned 205 yesterday. Level 2 was a bit less than level 1.

I'm not tryin to be insulting, but could you possibly be looking at the wrong thing? Maybe a weekly total or something? I don't know how "new" it is to you, but I just got mine and could totally see doing that.

Outside of that I would say its some kind of malfunction. I wouldn't log 600 cals. You would be safer to log either what you burned yesterday or nothing over 200.

mlv333

It does seem like a lot, but if you've been doing the same workout for a while and your body was used to it maybe the first time you switched things around your muscles were intensely working out. Just a theory.

etarre

I have a different type of HRM, but mine requires you to manually go in and erase the number of calories for each workout before doing your next workout-- did you clear the calorie counter before your second workout? If not, that second figure could be for both workouts you've done with the HRM so far....