Originally Posted by
Campag4life
With all the science...and perhaps some may take exception to that claim...of training with heart rate within targeted zones...and heart stroke volume and strength being a major contributor to sustained power, doesn't it make more sense to train to heart rate versus power?
No because power lets you rack up more of the right training stress in less time.
Once you cross your lactate threshold it accumulates in proportion to the fourth power of exertion so starting an interval a little too hard significantly limits what you can average and how much work you can do.
Unfortunately heart rate lags; so if you're pacing off it you over-do it in the beginning.
Heart rate also drifts upward so by the end you're not working as hard as you could.
(my Garmin stopped crashing like that after I upgraded from the original 2011 firmware)
Heart rate is also influenced by other factors like unseasonably warm weather. On Monday when it was 93 degrees I went for a ride at a comfortable endurance pace but after an hour was a couple beats shy of my LTHR although averaging just 130W not 184W. Obviously if you pace to what your heart rate monitor says in situations like that you won't work hard enough. Sometimes that's obvious because it doesn't feel hard enough, but other times it just feels tough because you're tired and you should dig deeper as long as you're not over-reaching or over-training which you don't know to do without more reliable instrumentation.
That sort of erroneous input to your training data can impact multiple workouts.
In exercise physiology we model training stress as decaying impulse responses over a long term (6 week decay) representing fitness and short term (1 week) freshness with the difference between them stress balance with some sustainable maximum.
When you inflate your short term or acute training load due to higher heart rate from environmental conditions you may dial back following work-outs when you don't need to.
The reason I ask is because we each can pretty easily compile our heart rate zones or targets....but much more difficult to assign targets of power to train to.
Hardly. To calculate heart rate zones I go out, ride a little harder than the last time I checked for 30 minutes, take the average over the last 20 minutes, hope I didn't set an unreachable target because my heart was a bit fast due to heat or minor illness, and dump the resulting number in my computer.
To calculate power zones I ride shorter and longer intervals then click "save" on the critical power screen.
Who is to say any power target is ideal...or even a menu of targeted power zones for a training schedule. But training to heart rate zones...if the heart is the true engine...
It's not.
Your muscles are the engine and you're interested in all the physiological changes that improve their performance through more oxygen and less lactate like growing more mitochondria and capillaries.
Heart rate is just a side effect, and for most durations of interest (note the gulf between LTHR and maximum) how much blood it can pump is not the limiting factor.
Yes, power will come by training to heart rate, but it seems that training to power zones maybe a bit less sound of a technique.
Training with power often produces significant power gains over training with heart rate alone.