Get a
heart rate monitor. A little bit of cardio to get you to your anaerobic threashold (~145 bpm) is perfect. Your blood flow is drastically different at rest, and at the AT. When you walk into the gym, the majority of your blood flow is to your organs. At your AT, the majority is to your muscles.
It's obviously a huge stress to divert all this blood flow in a few seconds, like if you just went straight to the leg press machine.
Some people say you should take 15 minutes to warmup, but I can never wait that long. 5 minutes seems like an eternity.
Now blood flow is optimal. Do about 4 sets of warmups for the muscle group in question. None should make you tired. Sets of 8,6,4,2 with
increasing weight.
Stretching has not been shown to prevent muscle injury. Incremental warmup sets have.
Fudo