Now in training we get some benefits from each workout. These benefits are adaptations which last for a certain duration of time and they go away if the adaptations are not worked on within a certain amount of time, which depends upon the stress created by the workout and your adaptive ability etc.
Now from the same workouts you get certain fatigue. This is cost of the workout. This fatigue also lasts a certain amount of time dependent on various factors. On a very simple and logical level the gains your acquire from any workout is simply:
Benefits (adaptations) – Costs (Fatigue)
Therefore the less the fatigue caused by a certain workout for the same adaptations, the better the gains. This is called the two factor model of training.
However there is a second point to consider. The duration of adaptations and fatigue. You have to repeat the stimuli before the previous adaptation fizzles out, but you also have to recover between workouts. You have to prevent fatigue from compounding. What does this mean?
Lets say the adaptations from a workout last 72 hours and your fatigue only lasts 24 hours. You workout every 48 hours. This is good as the adaptations compound but the fatigue does not. However let us say the fatigue lasts 48 hours. This means not only do your adaptations compound, but so does your fatigue. and remember that workouts are not your only source of fatigue- your daily life is as well. So fatigue will tend to compound more than adaptations.
Therefore this brings into play the principles of-
1. Energy Conservation– Switching between antagonist movements, taking active rests between sets, performing breathing exercises before and after the workout. resting more in general and engaging in relaxing activities and avoiding stress.
2. Training Economy– You have to use the least amount of volume and exercises possible to get the adaptations you want. You have to learn how to make efficient training programs and learn how to get more from less.
3. Optimum training frequency, volume, intensity and tonnage- You have to figure out the combinations you respond to, because this will determine how you adapt (or don’t). For example- high frequency low volume medium intensity training works. Low frequency high volume medium Intensity works. But high frequency and high volume medium intensity does not work.