So many coaches, especially the ones with mouths far bigger than their brains, make this mistake…more training is not the same as effective training. Or, as I used to tell the martial artists I tried to teach, exhaustion is not a training principle. Actually, it’s not a principle for anything useful in life that I can think of for most people.

You are much more likely to cultivate a healthy physical training discipline if you know when to end a training session than you are if you, or the pseudo-trainer/coach you are working with, pushes you to your limits routinely. Training should leave you with a satisfying sense of having done work, but rarely should it leave you feeling blown out.

We’ve already established that 80% rule works wonders for training. Something that I wrote about in here after being enlightened about it by Max Shank. It means that if you can do 12 reps on a given weight do 9, and so on. Always leave some in the tank.

As with most great training insights, it’s so simple that you’d be forgiven to ignore it.It works great in the bigger picture of training too when you look at beyond of just sets and reps. Do your session but stop and walk into the sauna when you are 80% done. In the other words, don’t chase tiredness, getting exhausted or gassed out. You get the point.

Source: 80% – The Key to Happier and Healthier Life?