Starting a stretching routine is a great idea. But while it seems simple, chances are you’ve heard conflicting advice: Should you stretch before a workout? After a workout? Don’t stretch at all?

Here’s what you need to know.

DO: Know Why You’re Stretching

First things first: Whether you need to stretch and how you should do it depends on your individual body, activity level and goals, says physical therapist Doug Kechijian, PT, DPT.

Stretching can help you develop the mobility you need to get through everyday life, your sport or your workout. “If you lack the positional ability to do a movement, your body will work around the program and compensate,” says Kechijian; that can lead to injury.

DON’T: Stretch to “Lengthen” Muscles

But that’s the point of stretching, right? Not quite.

While you may experience some short-term changes in flexibility, "you’re not actually changing the muscle at the local level," says Kechijian.

He explains that your body’s mobility and range of motion is actually modulated by your nervous system. When you stretch, you’re tricking your nervous system—convincing it that it’s safe to be in a lengthened position.

DON’T: Do Static Stretching Before a Workout

While many of us learned that static stretching (holding a stretch for 10 seconds or more) was the best way to loosen up, studies have shown the opposite effect.

Research published in the Scandinavian Journal of Medicine & Science in Sports found that static stretching before a workout resulted in a decrease in strength, power and explosive power output.

That’s because static stretching "relaxes your muscles rather than priming them to work," says strength coach Jonathan Mike, PhD. "Such relaxation isn’t beneficial if you’re getting ready to exercise."

“It may help your body begin the recovery process,” says Mike.

DO: Dynamic Stretching Before Exercise

Instead of holding a position, keep moving as you stretch before a workout.

“You’re moving your body through multiple planes of movement. Think walking lunges, leg swings, step-ups and resistance band pull-aparts. This will increase your body temperature and prep your muscles to fire when you work out,” says Mike. That means your muscles will be more efficient.

In addition, studies have shown that dynamic stretching can improve range of motion, muscular performance and body awareness.

DON’T: Push It

While it’s tempting to think that further is better, that’s not the case with stretching. You can overstretch your muscles, leading to injury.

Stretching should never be painful. “You need to be mobile enough for what you do in your daily life, and maybe a little bit more, so you can be adaptable,” says Kechijian.

For example, a ballerina’s flexibility “bank account” will be higher than a regular person’s, but you don’t need to be in the same extreme positions as a dancer to get through your day.

What’s more, a study in the International Journal of Sports Physical Therapy found that age and gender matters, too.

Women and adults over age 65 benefit more from static stretching (when not immediately preceding a workout). Younger men, though, respond better to the contract-relax style of stretching, in which you first contract the muscle before stretching it out.

DO: Build Strength and Stability

“Mobility is great. But if it’s not backed up by stability, then you start to run into problems,” says Mike. “It’s like building a house on clay. It looks fine on the surface but it’s not going to remain standing in the long term.”

Lift weights to build the strength you’ll need to maintain the structural integrity of your bones, especially as you get older.

In addition, being strong and stable "tells your nervous system that you’re OK in various positions," says Kechijian. "In turn, your brain will allow your body to achieve a greater range of motion."

DON’T: Focus Only on a “Tight” Muscle

If you have a tight hamstring, it may be tempting to stretch your legs every chance you get. However, a completely different muscle or group of muscles may be responsible for the pain.

For example, low back pain is often the result of tight hip muscles. Instead of focusing only on the muscle that feels tight, pay attention to the other muscle groups around it or talk to a physical therapist for advice.

DO: Make Stretching a Habit

Make time to stretch: Spend 10 to 15 minutes a day moving through some dynamic stretches. Not only will it give you a reason to get up from your desk but you’ll feel better, too.

DON’T: Bounce!

While many of us were taught to “bounce” while holding a stretch, this technique is no longer recommended due to the increased risk of injury. Instead, move smoothly through your full range of motion.