The consensus is that athletes make more progress over the long term if they do not work at the same intensity during each workout. One or two workouts per week should be more difficult and the remaining sessions should be light or moderate.
Maya the Virtual Coach described exertion levels as follows:
- Easy (E) - Used mainly for warm-upon as a main part of a long session. This pace is very comfortable.
- Steady (S) - Steady pace is one gear up. This is a pace where you can still have a conversation but you are slightly out of breath.
- Moderate (M) - A bit harder than steady. This is a pace where a conversation becomes difficult and breathy
- Moderately hard (MH) - This pace requires concentration to maintain the intensity - though when you are very fit you can keep this up for a longer period of time.
- Hard (H) - Above the lactic threshold and very much out of the comfort zone. It is quite uncomfortable to maintain this pace.
overload + recovery = adaptation
Challenging the body by applying stresses in the form of training loads. The more you do, the more you are capable of doing. With an adequate training load, both overall fitness and performance can be improved. Frequency, duration and intensity are all factors that effect the training load. Training loads should be gradually increased.
Rest allows the biomotor systems to recover and become stronger. Not quite like the Six Million Dollar Man, "Better than he was before. Better, stronger, faster."
The body's response to the training load.