Originally Posted by
socalrider
To see how off the garmin 305 is, I used it on a fairly fast beach ride down the SA trail.. Here is the crazy calorie data.. 2:24 ride for 48 miles gave me a calorie count of 3587 calories. Even at the max 16cal/minute threshold that should only be 2300 calories..
MY HR was 150avg - 178 max.. So take what the Garmin is telling you with serious skepticism.. I normally use a Polar or Suunto HR when I ride which gives more realistic numbers..
Well I just put my Powertap on my MTB and went for a quick 1h 20m shake down ride. The thing is awsome, Since I am a guy I didn't read any instructions just fired it up and took off.
It seemed to read pretty low but steadily increased to around 160 WATTS, but I couldn't seem to get much higher even when I pushed alot harder. I thought wow 200 watts must be
hard to get to. So I stopped and looked at the display and noticed it was AVERAGE WATTS. I immediatley set it to real time WATTS and took off again. Now I was consistantly riding at
220-250 at about 17mph. In 80 minutes at a pretty decent pace, the Powertap indicated I burned 800Kj which relates to 800 calories or about 500-600 cals per hour.
The training with power literature also states TDF riders on a 5 HOUR stage burn about 4000 cals. Thats about 800 cals/hours (24mph+ avg??).
So as I suspected getting over 700 cals per hour would be very hard. And these 1300-2500+ cals per hour estimates are pure fantasy.
I was surprised how fast the WATTS rise even on a moderate climb. I went under a bridge and pushed it up the "on ramp" to the trail and hit 1034 WATTS. This
was in the saddle not near a maximum effort, but pushing 250+lbs up a hill does take some WATTAGE. I will have to try some maximum effort sprints just for fun.
I was really impresssed with the speed of the updates on the read out.
So 500-700 cals per hour seems to be about right (for pretty hard effort).