Short on time?? A tip from NASM...

Try warming up for five minutes on an elliptical trainer before your workout. Maintain good posture and pull in the area just below the belly button as you count to either 10, 20, or 30 depending upon your capacity. This will enable you to get your body warm quickly as you use your glutes to move your legs into hip extension (legs going behind you) while stabilizing large muscle groups. 

This five minute cardio warm-up is a quick and efficient way to begin your workout!