Each time you strength train, you create micro trauma to the muscle tissue itself. The body then works to repair this muscle and build it up so it's just a bit stronger. This process takes timeβresearch states from anywhere as short as 24 hours to as long as 72 hours, depending on intensity. If you're hitting the same muscle group day in and day out, you're causing more damage before the previous damage can be completely repaired. So, you're working really hard and gradually getting less and less results. Every time you train, think of it like digging a small hole. Your body then fills the hole back in and adds just a bit more for good measure (which means strength gains). If you're digging at a faster rate than the hole can be filled, you're going backwards instead of forward. Repeating the same exercise or exercises every single day also opens the door to injury. "Repeating exercises such as Bench Press or Power Clean every day can be a pathway to the number one cause for fitness injuries, and that is creating 'over-use,'" Mikula says. "The body does not have ample time to recover from the training stimulus or is unable to deal with the amount of localized stress being placed on an isolated part of the body. It's hard to admonish someone for working too hard in the gym. Dedication and intensity are hallmarks of great athletes. But you also have to be smart about how you spend your time. If you do the same exercises or hit the same muscle groups in the weight room on a daily basis, you're not getting bigger or strongerβyou're inviting injury and wasting time.