Idaho Athletic Club trainer Kristy Lageson starts every workout session for her clients with a five minute warm-up followed by what's called dynamic stretches.
"Dynamic stretches are moving flowing stretches," says Lageson, "Not just standing and holding a stretch. You're moving, wiggling your arms back and forth and stretching your chest muscles." Static stretches are the ones people usually think of. They are usually held for 15 to 30 seconds at a time.
Lageson says they're best reserved for after your activity.