James Watt, inventor of the horsepower and who is honored through the name of the unit of power called the Watt. Power is what drives the pedals around and propels the bicycle forward, through corners, up hills, and into the fierce wind.
I love the Watt. It tells me how hard I'm working and whether I'm working too hard or not enough. I used to do the same with heartrate but something about the Watt feels more precise than BPM ever did. There were plently of times in the past when using just HR that I couldn't get it up to the targets. Science now tells me that I was probably fatigued as a result of over-training. Science was right.
It's hard to over-train with a power meter. That is unless you lack the discipline to actually follow the plan for your workout. Group rides are notorious for this breakdown in following the plan and sticking to your numbers. That's why I like to train alone most of the time. No distractions and no excuses for not following the plan.
With a power meter I know what recovery actually means now. In the past, after one or two hard days, I would plan on going out for a few hours and just take it easy. Easy meant not doing intervals or sprints. Anything else was fair game as long as the legs didn't completely quit. My recovery days in the past were in fact additional hard days of training. I never gave myself the chance to recover properly. Recovery would be forced upon me eventually. It was also progressively more difficult to feel "fresh" week after week even after my scheduled "active" recovery day.
That has changed now thanks to James Watt and the brainiacs behind the invention of power meters for bicycles. The power meter doesn't solve everything. You still have to have the discipline. I did two sessions yesterday, thirty minutes of 15 sec on, 15 sec off, at 150%+ FTP intensity and then the local Greentree practice Crit to acclimate myself with riding in a fast moving pack again. First race of the season for me is this Sunday.