Do You Really Need to Stretch? Science Says Maybe Not

If you’re looking to build both strength and flexibility, you might assume that lifting weights boosts strength while stretching enhances flexibility. However, new research suggests you may not need to stretch at all to improve flexibility—resistance training alone might be enough.

A recent randomized controlled trial compared the effects of resistance training and static stretching on strength and flexibility in healthy, active adults. As expected, those in the resistance training group gained more strength. Surprisingly, they also improved their flexibility just as much as the stretching group.

While some believe that increasing strength could reduce mobility, the opposite appears to be true—provided you perform full-range movements rather than partial reps. Research supports the idea that performing exercises through a complete range of motion—what Arnold Schwarzenegger famously referred to as “a stretch and a flex”—delivers both strength and flexibility benefits.

The study’s findings suggest that lifting weights through a full range of motion enhances flexibility by improving the interplay between muscles, tendons, and ligaments. Resistance training under load forces these tissues to work together, increasing strength and enhancing movement efficiency. Additionally, training through a full range of motion strengthens muscles in positions typically associated with stretching, leading to neurological adaptations that improve mobility.

This isn’t an isolated finding. A comprehensive review of 11 studies concluded that strength training is just as effective as stretching for improving flexibility. Beyond flexibility, resistance training also enhances joint stability, reduces aches and pains, and fortifies the body against injury.

This doesn’t mean stretching is entirely useless, but it may not be essential. If time is limited and you want to optimize both strength and flexibility, prioritize resistance training with exercises that emphasize full-range movement—such as deep squats, lunges, and Romanian deadlifts. By doing so, you may get the best of both worlds in a single, efficient workout.