If stretching is part of your pre-workout warm up ritual, a study published in the Journal of Strength and Conditioning Research offers a tip that could help you reach new personal bests: Go with a dynamic style of stretching instead of the static stretching you did before exercising in high school gym class.
After determining one rep max (1RM) for the barbell squat using a group of recreationally active 18 to 24 year old males, researchers assigned some subjects to an active dynamic warm up while the rest performed passive static stretching. A few days later, they switched to the other technique.
Squats performed after both stretching styles showed that old school pressure against the joint effort reduced 1RM by about 8% and decreased lower body stability by 23%. To warm up dynamically, put your body through a couple sets of reps on weight machines with no or very little resistance selected.