People put all of their efforts into the gym, some train hours per day. Others are in the frame of mind that it all comes down to what you eat, they meal prep and count calories and are usually pretty lean. Both of these approaches combined are a great way of taking your fitness (and weightlifting) to the next level but there is one major key component missing in this link and if it isn't addressed then this whole structure that is your training life will fall apart. Fast.
Mobility is the key to making sure you can come back and hit that workout with full intensity every day. You can't hit the right positions in weightlifting if you start to hit the limits of your mobility and flexibility. When you start to get tight; the joints that those tight muscles cross over become restricted and then when you try to move in a way that you normally would, it puts strain on that joint and that's when injuries happen.
The answer to solving and/or preventing this is relentless mobility. Start stretching when you're sitting in front of the TV or when you study or just standing around. This is the simplest yet most under utilised tool to keep your body healthy and growing safely. If you start a regular stretching routine you will see those aches and pains decrease. That bad knee suddenly isn't so bad. That annoying catch in your elbow suddenly disappears or that pain in your shoulder every time you put a bar overhead will disappear.
Put a system of stretches in place on a daily basis and watch your fitness grow. The weights on the bar will increase and all you had to do was stretch.
Remember to train smart, lift hard and you'll set pr’s.