Originally Posted by
Hermes
What I found when I started training with power was that I was not generating as much force on the pedals over time as I thought I was. Heart rate and level of effort are okay but not great for determining pedal force. If there is an analogy, it would be that in the gym, I would bench press whatever, 100 pounds. I know it is 100 pounds and the force required to lift the weight remains the same. As I do more reps and sets, fatigue causes the level of effort to feel like it increases when in fact it is the weight is the same. I swear someone is adding weight.
To expand on this in a more general way:
Most people don't hold a steady power when they ride. That's why almost everyone prefers to see the avg over the last X seconds instead of just at that instant. It jumps around a lot. It's like you benched 100 lbs, then 120, then 97, then 20 for a second while you changed your position on the saddle sightly, then 140, etc. Except on a bike, it's like you're benching whatever is on the bar at that moment, but the plates don't have numbers do you don't know how much you're lifting. Each pedal stroke has a different amount of force. (Not usually
huge differences.)
A power meter is like a scale so you know exactly what you're pressing. HR is how it's affecting you. Heart rate is influenced by things that aren't relevant to training. You want to be bench pressing 100 pounds whether you had too much coffee today or not, so when you're at the gym you go by weight not HR. I'm not saying you have to use power and ignore everything else, I'm saying people should be aware that HR and PWR are measuring different things.