If you’re leading a team (or children) to being tougher, the best method doesn’t involve taking away their control. You can’t force them to endure suffering without giving them the chance to regulate that suffering. If it’s being imposed on them, it won’t teach them anything. Like overly strict parents whose children go crazy with partying and not attending class when they hit college.
It’s the act of being given the choice to control the extent of their pain that they grow the mental muscle to willingly endure it later.