What form of weight do you use for an HRM or similar device?

[Jacomus]

I don't actually use a HRM any more, or really care about estimated calories burned etc, but I was chatting to a friend who does.

When I used to do it, I would enter the weight as gross weight: Me + bike + luggage

He says that's disingenuous as I'd be over-stating my weight, therefore overstating my calories burned.

His HRM booklet asks for 'rider's weight', but I think that that there is slack in the wording.

I reckon that as I'm attached to the bike, it functions as one unit, essentially increasing my weight.

[Kim]

The only thing I use that's weight-aware is Strava.  It understands that I weigh X and the bikes weigh whatever they weigh.  Annoyingly, it has no concept of luggage, to go with its non-concept of various common types of cycle and it's non-concept of the Garmin eTrex series.

I've fudged the bike weight upwards a bit to allow for the bare minimum of luggage that I'm likely to be carrying, and accept that it will under-read when I've got a touring or utility load.  It doesn't really matter, because its estimates are basically useless anyway, as it fails to allow for the aero and rolling characteristics of different bikes (it thinks I work harder on the recumbent than on the Brompton, for example).


More generally, I agree that gross weight is what matters, but it's likely that a cycling-oriented HRM will incorporate some sort of 'standard bike' fudge factor into its calculations already...

[T42]

My bike computer uses total weight to estimate power output. Don't see that that has any connection with the HRM component, except that they're displayed in parallel on the PC along with speed and altitude.

[Ningishzidda]

The Vehicle Dynamics formula

Power Pf  = Slope x weight x (Velocity / 375)

requires 'weight of vehicle'.


It would be silly if 'weight' was the weight of the car driver alone.... 

[Jakob]

HRM calculates calories burned based on some formula of heartrate and bodyweight. Some want height & age, so they have a reasonable idea that if heart rate is Y then that equals X amount of calories burned. It doesn't care if you are running, cycling, swimming, so if you include the weight of your bike, you are skewing the results.