The New York Times just had an article dispelling the well-worn advice to stretch before exercise:
“The old presumption that holding a stretch for 20 to 30 seconds — known as static stretching — primes muscles for a workout is dead wrong. It actually weakens them.”
Instead, we should prepare for athletics with 5-10 minutes of very light aerobic activity, and only 5 minutes of rest time before moving on to the workout.
The right warm-up should do two things: loosen muscles and tendons to increase the range of motion of various joints, and literally warm up the body. When you’re at rest, there’s less blood flow to muscles and tendons, and they stiffen… A well-designed warm-up starts by increasing body heat and blood flow.
Yoga is a great workout because it stretches as it strengthens. It seems it would also be a great warmup for other types of workouts:
Stretching muscles while moving… a technique known as dynamic stretching or dynamic warm-ups, increases power, flexibility and range of motion.
This is also a good reminder for teaching or practicing challenging poses: warm up all joints and connective tissue that will be used by starting with simple poses and/or repetitions.