On 4/29/2021 10:05 AM, Lou Holtman wrote:
Op donderdag 29 april 2021 om 18:02:23 UTC+2 schreef :
On Thursday, April 29, 2021 at 8:40:22 AM UTC-7, Mark cleary wrote:
What do you think of this power meter. I don't want pedal one until they come out with Shimano cleat model and I don't want a hub based. What if any does the group use?4IIII PRECISION PRO SHIMANO ULTEGRA R8000 DUAL-SIDED CRANKSET
Deacon Mark
Since I'm not racing it doesn't interest me in the least whether I know exactly how much power I'm generating or not. My Garmin calculates the amount of Calories I'm expending by assuming that there is no wind. So 1.2 calories per second of actual riding time is about 200 watts of power output. If you have a head or tail wind you can adjust your output per second during that time though circular courses generally have the same up an down adjustments so that the Garmin is fairly accurate. The Garmin program tells you the actual moving time so that you can calculate calories per second. Of course, this only counts on flat ground and full out efforts, most of the time you are riding well below your peak and so the readings are inaccurate as hell. But why do you need to know how much power you are generating?


Tom it isn't about you this time. Why do you need to know the power you are generating? As a reference for your trainings intensity. You are not into that? OK, don't use them. Simple.

Lou


Also, Tom, "1.2 calories per second of actual riding time" comes to
4,320 calories per hour. That's enough for most cyclists to cover 100
miles; nobody - and I do mean nobody - is doing that many *kilo*calories
[or big-C Calories] for an hour, while 200W for a full hour is quite
plausible for many - maybe even me. If you meant actual *calories*
[small-C calories], so 4.32 big-C Calories, then I can do that in one
minute, and I'm nobody special.

Working it another way, 1.2 kilocalories per sec at 25% metabolic
efficiency (a plausible number), is close enough to 1.2 *kilo* Watts.
Plausible for strong sprinters, but not for a full hour. 1.2 calories
per sec comes to 1.2 *Watts*. Nobody's that weak.

Working it a third way, 200 Watts is 200 Joules/sec, close enough to 200
small-c calories per sec at 25% efficiency, or 0.2 big-C Calories per
second.

Finally, no, the Garmin Calorie estimate is *not* fairly accurate, in
general. I used it for years, then I got a HRM. My Calorie estimates
changed dramatically. Then I got a power meter. Another dramatic
Calorie estimate change.

Mark "There are wrong answers in math" J.