How to calc human bicycle power in watts

[Dyllon]

Homework Statement

How to calculate Lance Armstrongs power output/calorie consumption at 30 mph, 125 miles on level ground , no wind, 157 lbs plus 16lb bike?

Homework Equations

What equations do I use?

The Attempt at a Solution

I'm 14 years old, where do I start

 

[Mentz114]

I don't think there's enough information given to do the calculation. The energy used will be a function of the resistive forces that have to be overcome by the cyclist. In an ideal world, traveling at constant speed on a flat track uses no energy, but in reality there's friction and wind resistance and other things also.

Doesn't Lance Armstrong weigh more that 157 lbs ?