Accuracy of bike rides

[sepculator]

On a recent bike ride i averaged 9kcal/min or more accurately 39kJ/min according to the app. 39kJ/min as an average number would suggest I have been doing an average of 650Watts pedaling. That seems tremendously high.

I am wondering why. I can only assume that there is a massive difference between energy burned in the body (to pedal, to cool, to breathe ...) vs energy going to the pedals on the bike. Most people would say 200-250Watts is a high average for pedaling.

Any insights on this?

S.

[ewitz]

Ignore any estimates of energy expended. To many variables (weight of bike, wind).  

Unless you have a power meter on your bike it is a totally useless guess. 

[sepculator]

Shouldn’t calories be based on heart rate, age and weight and possibly elevation? Why would it be inaccurate.

[ewitz]

A healthy 150 pound 50 year old generating 200 watts for one hour with and average heart rate of 150 and an unhealthy 50 year old generating the same power over the same time with and average heart rate of 200 both expended the same energy on the bike.  

Power is energy divided by time.

[SunsetRunner]

I wouldn't count on it. On my bike rides, I got a bit disappointed with the results because the heart rate was all over the map. Use it for fun but don't really be serious about tracking anything with the Sense. Other heart rate trackers did not do better except the Apple Watch which according to the Sleep scientist in Vienna it was an amazing tracker and very accurate even with weight training.

Well, I don't have an iPhone and I don't get to enjoy its accuracy.