Heart Rate Monitor Estimates

[Intension]

At the moment I am weight lifting 3 times a week and running 3 times per week. I have begun using a heart rate monitor to help monitor my intensity during workouts. It has been great so far for this purpose but I would also like to use it to assist in kcal burned estimates per workout.

Since my workouts are moderate-high intesity I am not sure how to get the most accurate reading from the heart rate monitor. This is mainly due to extended metabolic effect of both activities as well as the time it takes for my heart rate to go back to my resting heart rate after exercise.

When is the best times to start/stop an exercise session on the watch for getting a kcal burned estimate? Should I start it before the warmup or after? Also should I stop it before the cooldown or wait until my heart rate returns to my resting heart rate?

[SocratesTX]

The only way to get an accurate reading from a HR monitor is to calibrate it correctly and in order to do that you need to have information from a VO2 Max test.

[Intension]

Hmm... do you know if the fitness tests on the polar watches get anywhere close to a proper VO2max test? Even if it is give or take 5% or so?

My guess is it probably isn't as mine seems all over the place. When I first got the watch apparently my OwnIndex (VO2max estimate) was very poor and only about a week later it is now moved up to fair lol. This might be because I changed my activity settings since I had it on low (which was totally wrong). I haven't been able to find out how they work it out (what formula etc.) but it seems mostly to be based on resting heart rate, body weight and activity level. As a result I would wonder how accurate this really would be... Nevertheless if it gets the V02max close enough to the real value the estimates should be ok for what I want I would assume.

[Intension]

The only way to get an accurate reading from a HR monitor is to calibrate it correctly and in order to do that you need to have information from a VO2 Max test.

If I did have my real VO2 Max value (which I don't) when would you start / stop the watch? Also as the watch calculates calories burned even at resting heart rate should you subract the average amount that works out too?

[SocratesTX]

If I did have my real VO2 Max value (which I don't) when would you start / stop the watch? Also as the watch calculates calories burned even at resting heart rate should you subract the average amount that works out too?

Once you have VO2 numbers, you calibrate the monitor/watch to those figures. They are programmable. Once you have that you will get an accurate reading about your performance and such.

[Intension]

Thanks. I understand that I need to know my V02max for the most accurate reading. However what i'm really trying to find out is for example if I do happen to get my V02max tested and use this... how would I go about measuring the kcal burned from the exercise.

For instance today I went for a 5km run. My question in this case is do I stop the HRM exercise session as soon as I stop running or wait until my heart rate returns to its resting heart rate?

So today my average heart rate over the run was about 165bpm and max 178bpm. When I stopped running I walked for about 20 minutes so my heart rate stayed above 100. Ever since then (more than 2 hours later) my heart rate is up around 85bpm still whereas my resting heart rate is below 60.

Considering when I go for a slow walk for recreational activities my heart rate is usually only just above 90 and only goes up to 110 on slight inclines it makes me wonder if for about 2-2.5 hours after running I would be burning the same amount of calories just at rest as I would going for a slow walk for 2 hours (so about 3.75-4km/h).

If I wait until my heart rate goes back down to the resting heart rate I think this would almost double the kcal burned value compared to when i stop it straight after I stop running. What I really want to know is what is the right way to get the best estimate if I already knew my V02max value?

[Jules Verne]

You need a HR monitor that calculates calories from resting HR, VO2max etc.. It's not a linear equation, so just knowing average HR isn't going to be very accurate at all.

If you get a decent estimate of VO2max then I think the monitors that calculate calories can be reasonably accurate (say within 10% or so) for cardio activities (not lifting)

[Intension]

You need a HR monitor that calculates calories from resting HR, VO2max etc.. It's not a linear equation, so just knowing average HR isn't going to be very accurate at all.

If you get a decent estimate of VO2max then I think the monitors that calculate calories can be reasonably accurate (say within 10% or so) for cardio activities (not lifting)

Yea, my heart rate monitor does do that but the VO2max is an estimate based on a test the watch performs (which is also based on resting heart rate and other user stats). It is the polar F11.

I guess I will just assume the V02max is somewhat close and use that as a rough indication of what i'm burning. By the way I also asked polar about whether to include the kcal burned after exercise until heart rate returns to resting heart rate and they said it was only designed to be used during exercise.

How do you think I might be able to estimate the calories from weight training? With a partner my current lifting sessions aren't usually much over 30 minutes (if that) we are not having too much rest inbetween exercises and low sets. I assume due to the 4-6 rep range, slow cadence and such the calories burned during are low but their would be some metabolic increase after training for some time. I know the NFPT manual suggests as an approximate 250 kcal for 4-6 reps over a full hour but this doesn't really specify rest intervals and the effect on people of different weight etc.
Is there any other way of getting an educated estimate without spending too much on getting tests like the V02max etc.?