Changes

The diagram below represents a personal hypothesis based on my observation that long runs and speedwork can be combined. After a long run, it is quite practical to perform speedwork and gain benefits, when doing a long run at that point in the recovery would produce serious fatigue or injury. My hypothesis is that the long run primarily affects the endurance fitness and speedwork primarily affects aerobic fitness. Thus a long run triggers the endurance supercompensation curve (red), but does not have much impact on the aerobic supercompensation curve (green). Likewise, the speedwork triggers the aerobic supercompensation curve (green), but does not have much impact on the endurance supercompensation curve (red). In practice, things are probably a lot more complex than this, but I believe this is a useful model. (As George P. E. Box said "[[All models are wrong]], but some models are useful".)