Should You Stretch Before a Workout?

Answer: It's a common myth that stretching out before a workout is beneficial--in fact, it's actually unsafe. Stretching a "cold" muscle can actually increase your risk for injury and reduce your strength, which is obviously detrimental to your workout.

Why Stretching Before Working Out Causes Injuries

The reason why physical trainers don't recommend stretching out before exercise is because the muscle is "cold"--it has little flexibility. If you stretch your limbs while your muscles are cold, you increase your risk for injury because your muscle has a harder time adapting to the stretching.

To save your muscles from a potential injury, warm up first with a light 10 minute jog or run on the treadmill, which helps warm them up and increase flexibility. Use static--or if you're partnered up, isometric--stretches, which are generally safer than "ballistic" (stretching your limbs beyond its limits) stretches.

Stretching and the Strength Factor

Another issue is that stretching "cold" also reduces your strength significantly, which can hinder your ability to lift heavy. According to a study reported in the May 2006 issue of Athletic Therapy Today, stretching before working out can decrease strength and power by up to 30 percent, with marked decreases in vertical jump and depth jump height.

This is a problem especially for bodybuilders, who need to have optimum strength levels in order to "lift heavy". Losing your strength and power can reduce your ability to lift heavier weights, making it harder to build muscle and increase muscle strength. If you play competitive sports, the damage is still significant--most sports involve your ability to jump or leap, which cold stretching hampers.

Bottom line: If you want to keep your exercise performance maximized, you're advised to save the stretching until after your warmup. Remember to keep the warmup light and moderately-paced--there's no need to have a mad sprint on the treadmill.

Source:
Mark S. Kovacs, "The Argument Against Static Stretching Before Sport and Physical Activity" (mirallas.org)