Relationship between HR, power, anaeric threshold and rpm

Originally Posted by Smartt/RST

Steve's comments are right on, but for the informational benefit of the forum (and to hear myself "talk"), I have to add a couple of things concerning dkxkvtr's statements:
1) Recovery intervals have no role in the physiologic adaptations of MLSS (maximal lactate steady state - to use a lactate referenced definition) training, they simply provide a mental break during a form of training that is lengthy and both physically and mentally challenging. Adaptation occurs from extended periods of time spent at a POWER OUTPUT that is just just below, at, or slightly above your 30-60min TT power. Assuming power output is maintained/is similar, there is no difference between 3 x 20min vs 1 x 60min of this kind of training (for example).
Note: where to train in relation to your actual threshold power depends on the time of year, the races you are training for, your cycling experience and whether or not you are an elite athlete. However, for most of us, the training benefits are easily obtained from training just below our threshold...slogging through "the burn" isn't necessary.
2) In addition to Steve's comments, (and to harp on HR for sure!) HR can be influenced by fatigue (from the current workout or past workouts), hydration (and subsequent cardiac drift), body temperature, altitude, sleep, anxiety, caffeine, hormone release, illness...and...cadence (not to mention the exercise itself). Why? HR is nothing more than an indirect measure of the WHOLE BODY response to stress (not just exercise), which will include some or all of the variables listed above. This is, of course, the ultimate foundation for power based training....direct measurement of work done, no influence of other factors, ever.
Just to be snotty...physiologic adaptations to training at your 30-60min TT power include: increase plasma volume, mitochondrial enzymes, muscle capillarization, stroke volume, maximal cardiac output and VO2max ... also stimulates conversion of type IIb fibers to type IIa.
Rant over.