I am new to power training and over the last few weeks have experienced some numbers that really point out why I bought one. During interval weeks, particularly blocks, doing intervals on heart rate, in retrospect, seems pretty much useless. I usually do intervals wed-thur, and then sat-sun depending on the racing schedule.
OK.. short intervals, 3x1min with 1min rest x3 sets. Its easy to see that I go out way to hard, as power fades hard. 1-week later, watching power, I have nice steady efforts.
6-8min intervals. Wow, with power these seem EZ.. until I get past the halfway mark. HR is low to start, until the end, then it is over my old HR range for these intervals. These intervals I am performing WAY differently.
Biggest revelation.. I raced Saturday and about went hypothermic. But had a good race (MTB). Sunday I went out for a 3.5hr cruiser. I was feeling kinda rough from getting so cold, but my legs were doing pretty good so I decided to do a couple 1min efforts, not all out, but solid. Back home I looked at the efforts and compared with the efforts I did just 5-days ago (on wed)..
Wednesdays best 1min:
min HR 127
max HR 181
aver HR 162
min watts 418
max watts 622
aver watts 520
Sundays 1min:
min HR 144
max HR 172
aver HR 163
min watts 352
max watts 596
aver watts 524
I started Sundays effort up a mild climb cruising at 250watts. My HR was elevated a bit at the start which would normal send me to a higher max. But comparing to Wednesday the HR response is hugely different. This doesn't surprise me, cause I've always known it was going on. Especially after a hard day. But this example is very much the reason why I chose to get a power meter, and makes me feel real good about my decision.. For intervals, I am so glad I know longer need to watch HR. Not to mention all the other great info I have discovered!