Hold a dumbbell in each hand just above the shoulders, palms facing in.
Press the dumbbells above the head, straightening the arms. If you need to, you can use the power of your legs to get the dumbbells up by quickly bending your knees and straighten the legs at the same time as you straighten the arms.
Bend the elbows coming back to the starting position to complete one rep.
Do as many shoulder presses as you can for 40 seconds, followed by a 20-second rest.