As a rock climber, I can tell you that mental and physical fatigue are very distinct, very real things. But I'd have to say that before I got into climbing, I wouldn't have realized this.
There are times when you are physically capable of completing a climb, but your mental tiredness prohibits you from doing so. The very nature of climbing is scary, and your brain knows this. It's not just fear of heights, but fear of falling, and even failing. Every move you make is a little fatigue on your mind. You have to calculate it out, make the move, and beat all your fears at the same time.
Over the course of a climbing session, your mind wears down. You may be physically able to complete a climb, but your mind is just giving up. The stress overwhelms you. You give up.
There is another non-rock-climbing example. In Arnold's bodybuilding book, he talks about the mental aspect of bodybuilding. Not just in competition, but also in training. He gave an example of some famous bodybuilder who was having a bad day. He couldn't do some deadlifts (I think) that he was totally capable of doing, even with Arnie cheering him on. The guy was about to give up. Then a bunch of his fans showed up, and he wasn't about to disappoint them. He completed his set with ease.
you're right, weight training is 80% mental. on any given day, the work isn't that hard. cumulatively it's just a few minutes of effort and you've done it a hundred times before. you know when you finish you'll feel amazing, and you know in 1 month you'll have more solid results compared to today. you know all this.
but damn, sometimes you just want to quit for no reason at all. i've come so close to just walking out in the middle of my workout for absolutely no reason whatsoever. this is even after you've gone to the actual gym, which is a whole 'nother story.
There are times when you are physically capable of completing a climb, but your mental tiredness prohibits you from doing so. The very nature of climbing is scary, and your brain knows this. It's not just fear of heights, but fear of falling, and even failing. Every move you make is a little fatigue on your mind. You have to calculate it out, make the move, and beat all your fears at the same time.
Over the course of a climbing session, your mind wears down. You may be physically able to complete a climb, but your mind is just giving up. The stress overwhelms you. You give up.
There is another non-rock-climbing example. In Arnold's bodybuilding book, he talks about the mental aspect of bodybuilding. Not just in competition, but also in training. He gave an example of some famous bodybuilder who was having a bad day. He couldn't do some deadlifts (I think) that he was totally capable of doing, even with Arnie cheering him on. The guy was about to give up. Then a bunch of his fans showed up, and he wasn't about to disappoint them. He completed his set with ease.