Your Nervous System
The science behind becoming more fit is that your nervous system is the key to your fitness. In fact, the main pacing factor in training progression is often that the nervous system, and your ability to recover, hasn’t adapted to the movements and the volume required to take on more physical stress. That is normal. The secret is constant forward progress. It starts out slow, and then picks up steam as your strength and endurance builds, and your nervous system and recovery ability adapts.
Therefore, a scientific approach towards maximizing our odds of making progress requires us to design our plan around making it just challenging enough to make us mildly sore 2 days out, and then soreness is gone within a couple more days. If you made yourself more sore than that, or the soreness lasted longer than 2 days, you over did it!
New things challenge your nervous system
One exception to this is when you first start training, wherein literally everything challenging you do will make you sore. But even then, don’t train again until the soreness goes away. Another exception is when you incorporate new movements or movements you haven’t done in a while, because your nervous system isn’t used to them.
On the other hand, you don’t need to always make yourself sore, but if you never get sore you aren’t doing enough to optimize muscle growth.
Training Frequency
There is also something to be said for training frequency (a higher perspective of volume) or how often you train. If you train too infrequently, neither the nervous system, nor the muscles will adapt. You will get beginner soreness every time you train, preventing you from progressing, because you simply aren’t training regularly enough to adapt. It’s like any other sport in that regard. If you only run a few times a month, neither your distance nor your pace will likely improve much, if at all. You will essentially start over at each run, and get sore all over again. The same applies for resistance training. Training less than 2-3 times a week will result in negligible improvement in strength or intensity, both of which are necessary to build muscle.
Regular gradual adaptation
So, the prescription for optimizing your resistance training is regular gradual adaptation. Do just enough to make yourself mildly sore. Train again as soon as the muscle recovers. When your current protocol stops making you sore, you could:
- Improve your form
- Increase the volume
- Increase the intensity