Is Stretching Overrated? Strength Training Improves Flexibility

Key Points:

  • A new meta-analysis compared strength training with stretching and found that both increased flexibility and range of motion to a similar extent.
  • By training all your major muscle groups and joints through a long range of motion, you don’t only get better gains in muscle mass and strength, but you also improve your flexibility the most.

“Strength training will make you muscle-bound.”

Have you heard that one before?

It has been said for a long time that strength training shortens your muscles and makes you inflexible, even though evidence has continued to build in the opposite direction.

The evidence, however, has been scattered. That is, until recently, when a meta-analysis comparing the effects of strength training versus stretching on flexibility was published.1

The Term “Muscle-Bound” is a Stretch

A meta-analysis is a method of pooling together many individual studies, to better be able to draw conclusions from the big picture. In this case, we get a clearer view of how strength training and stretching compares when it comes to increasing flexibility when we take all similar studies into account.

In the article titled “Strength Training versus Stretching for Improving Range of Motion: A Systematic Review and Meta-Analysis“, the researchers gathered 11 studies comparing the effect of strength training and stretching on both range of motion and on standardized flexibility tests. The eleven studies encompassed a total of 452 participants, and the studies lasted between 5–16 weeks.

What the researchers found when they pooled all study results together was that strength training and stretching improved flexibility and range of motion to a similar degree.

Most studies tested flexibility in the hamstrings or knee extension range of motion, but shoulder, elbow, and spine flexibility and range of motion was also tested.

So Should You Never Stretch?

While this is good news for all of us who like to lift things up and put them down, it doesn’t mean that you should throw all forms of stretching in the trash.

Not every movement or joint position lends itself well to strength training, and nor do you always want to incur an extra training load. Gymnasts and dancers, for example, do lots of stretching to increase their range of motions in movements that would be impractical to load in strength training.

What’s more, stretching offers a specific and direct way to increase flexibility in a given joint or muscle.

  • Want to get better at putting your arms in a straight line above your head? Then practice putting your arms above your head, with or without a weight in your hands.
  • Want to be able to squat deeper? Work on your flexibility and range of motion by training deep squats, and simultaneously stretch in the bottom position, perhaps as a part of your warm-up or on your off days.

One doesn’t have to exclude the other, buddy.

Take-Away and Practical Application

There are at least two things I feel you can take away from this study.

  1. Train your whole body. You will only improve your flexibility in the movements that you actually do. If you neglect some of your major muscle groups or joints, you won’t improve your flexibility in them. You don’t necessarily have to train full-body workouts all the time, but make sure to hit all your major movements at least once a week.
  2. Train through a full range of motion. Use it or lose it. When it comes to range of motion, you will improve (or maintain) the range of motion you use in your training. Not only will full range of motion training improve your flexibility compared to half-repping, but it is also the most effective for building muscle and increasing your strength.2

To summarize: Don’t discard stretching; it certainly has its uses. But also don’t think you must stretch out all your muscles after a workout, lest you become muscle-bound.

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References

  1. Healthcare (Basel). 2021 Apr; 9(4): 427. Strength Training versus Stretching for Improving Range of Motion: A Systematic Review and Meta-Analysis.
  2. Scand J Med Sci Sports. 2021 Jun 25. Effects of Range of Motion on Resistance Training Adaptations: A Systematic Review and Meta-Analysis.