As a baby boomer, I'm at a point in life where I'm annoyingly reminded by my body that I have a finite number of stair-climbing reps remaining in my hips and knees. If I started climbing more stairs at present to increase my speed and endurance in climbing them, I'm reasonably assured the added reps would also shorten the remaining service time for those hips and knees and put me at more risk of breaking a hip in the process.
Thinking along those lines but for an elite athlete instead of a sedentary baby-boomer, does intensive training actually make the body more prone to injury? My understanding is that muscle growth is based on creating micro-tears through exercise that the body then repairs, adding more mass and and improving performance capability in the process. What does the recurring micro damage and repair from that repeated training do to the resiliency of the muscle, however, and what kind of cumulative stress does such frequent training impart to the supporting tendons and ligaments? Is a player who trains more moderately actually at less risk? I'd be interested to know how the per capita rate of ACL tears and quad injuries compares to present from when Spring Training was the extent of a player's physical conditioning.