 Legendary boxing trainer, Kostya Mato, who coached both Muhammad Ali and Mike Tyson, famously said that no boxer can be knocked down by a punch he sees coming. Think about that. No matter how powerfully he is struck, his body will be able to absorb it as long as he is not surprised by it. At the pro level, power alone cannot knock you down, only being thrown off balance can. If you look at the most famous knockouts of all time, you'll notice the knockout punches were rarely the ones that looked the hardest, but rather they were the most unexpected. This concept applies far beyond boxing. You can't get knocked down by anything you see coming. Know what's coming. Expect what's coming. Arm yourself and design your environment for what's coming. On a similar note, a reporter once asked Muhammad Ali how many sit-ups he typically does in a workout. Ali's answer? Fifty. The reporter was taken aback, surprised that it wasn't much more. A champion heavyweight boxer surely can do more than fifty, right? Ali explained it was fifty because he only started counting after they started hurting. The ones before the pain didn't even register to him. Muhammad Ali understood the power of stress, and Ali was right. The reps you do after the burning starts are the only ones that matter.