Nobody wants to be the guy who crushes all the physical events and can't work as a team, or worse yet, crumbles like a weak bitch when he has to carry more than his personal load out. Additionally, training "harder" and not working on things like strength and recovery will lead to injury at some point in time. What we aim for is improving performance, and that means taking the time to get healed up. Your body's response to specific stimuli will be very specific in nature, if that makes sense. As you diminish the stimuli (thats your workouts) you diminish the input and the changes to your body. To put it simply, your body responds differently to deadlifting 250lbs twice than it does to deadlifting 500 pounds once. If you don't give it the required time off, your body will not have time to make the required adaptations to increase athletic performance.