Warm-up

First thing to do in a hockey warm-up is skate around the ice at a comfortable pace for about 5 minutes. You should skate in both directions and also incorporate backward skating.

Then you need to stretch.

While you are gliding around the ice you can:

Stretch your trunk by holding your stick above your head and then tilting your upper body to the right and then to the left 5 times each. Then twist your upper body from side to side 5 times each way.
Stretch your arms by holding your stick behind your back and lifting it backwards away from your body. Hold this stretch for 10 to 15 seconds and then repeat 5 times.
Stretch your groin by using lunges while you glide. With your upper body straight and your right leg forward, bend your right knee while keeping you're the left leg straight and behind you. Hold for 10 seconds and then stretch your other leg. Make sure to stretch each leg about 5 times.
Stretch your legs by holding your stick in front of you and bending forward at your hips. Bend until you feel a stretch in the back of your legs and then hold for 10 seconds. Repeat this 5 times.