To me, the key is fitting workouts together like a puzzle. For example, perhaps one day the focus of the workout is strength type efforts, where the cardiovascular system is not overly stressed, but the essential component of strength is benefited. The next day, a focus can be more aerobic. In other words, you are working on different “systems” on different days. One addition item. In a recent study, 75% of athlete’s polled (not sure of the amount in the study, but it was large) said they applied some type of recovery program to their training, like recovery drinks, massage, etc. I still think the biggest and most important, regardless of all the other things you try is sleep.Anyway, I'm encouraged by my performances this season - routinely hitting levels I've not seen since 2004. A testament to more structured and analytical training? Or just luck?
Flies and Bikes Blog
Physiology, training and the Masters cyclist
Pez Cycling has a brief article (Toolbox: What Does Every Masters Athlete Have in Common?) which touches upon the physical decline that faces the ageing athlete, and what to do about it. For one in his second half century, there's always something a little depressing about such articles, but at least there is advice, most interestingly on the subject of recovery from training: