Power and running

Quoted post said:

Originally posted by nhorscro
I've been reading all the posts about training with power and the various methods of measuring power on bikes. I was wondering how power is measured for runners. Are there fewer variables involved therefore allowing HR to correlate with power? Just curious.

It is very difficult to quantify actual human power production during running - attempts have been made using e.g., filming, measurement of ground reaction forces using instrumented force pads or shoes, etc., but the mathematical models are complex and require many assumptions. As for the relationship between exercise intensity and HR, it is influenced by the same factors (e.g., environmental conditions) when running as when cycling, and therefore the variability is the same. The good news is that since the relationship between running speed and metabolic rate is quite linear, there's much less need to measure power or some surrogate, e.g., HR.