Thirty seconds. That鈥檚 how long the National Academy of Sports Medicine recommends holding a static stretch to lengthen a tight muscle, says Mike Fantigrassi, the NASM鈥檚 director of professional services. But like all things sports related, timing is everything.
Hold a static stretch longer than 45 seconds before you workout, and Why that happens, no one knows for sure, though researchers believe stretched muscles are 鈥渓ess able to store energy and spring into action,鈥 writes Gretchen Reynolds on the New York Times鈥 Well Blog. So if you like to static stretch before working out, keep it to 30 seconds. 鈥淵ou get the relaxation of the muscle and some loosening without the negative effects of decreased performance,鈥 Fantigrassi says.
Post-workout, around 30 seconds is still the sweet spot for enhancing flexibility, Fantigrassi says. Hold it longer, and researchers have conflicting views on what will happen. the benefits stop at 30, so holding the stretch longer is simply a waste of time. (Unless you鈥檙e older than 65, in which case you鈥檒l want to to achieve the same benefit as your younger counterparts.) better flexibility and decreased stiffness come only after holding a stretch for three minutes.
It doesn鈥檛 appear that there are any negative consequences to holding a stretch, post workout, for up to five minutes. Just remember: It is possible to be too flexible. 鈥淢uscles function best at their optimal length,鈥 Fantigrassi says. 鈥淚f they鈥檙e too short, they鈥檙e weak. If they鈥檙e too loose around a joint, the muscle support isn鈥檛 going to be there for that joint, so that joint gets beat up.鈥 So unless you鈥檙e gunning to join Cirque de Soleil, don鈥檛 stretch that hammie past its optimal length. A certified fitness trainer or coach can help you figure out your sweet spot.
The bottom line: The National Academy of Sports Medicine recommends holding a static stretch for about 30 seconds to achieve better flexibility.