Warm-ups

#General — 5 minutes

Anything that raises core temperature. Bike, rower, brisk incline walk. Warm tissue is genuinely more compliant, and that is most of what a warm-up does.

No static stretching before lifting. Long static holds transiently reduce force output and rate of force development. The effect is smaller than commonly claimed and mostly gone within ten minutes, but there is no reason to accept it. Do static work after training or in its own session.

#Specific — first exercise only

Ramp to your working weight. Later exercises in the same session need at most one light set, because the muscles are already warm and the joints already loaded.

For a working weight of 100 kg:

Keep rest short — 60–90 seconds. These are not stimulating sets and should not fatigue you. If your warm-up leaves you tired, it is too long or too heavy.

#Lower body

Add 10 leg swings each direction and 10 bodyweight squats before the first squat set. Hips and ankles get a lot more range demanded of them than the upper body does.

#What warm-ups do not do

They do not prevent injury in any strong sense — the evidence for that is much weaker than the folklore. They raise tissue temperature, rehearse the movement pattern, and let you find the groove before load matters.

That is enough reason to do them. It is not a reason to spend twenty minutes.