By stretching, you increase the elasticity of your muscles — but could you also be stretching and increasing the elasticity of the arteries? Quite possibly.

That’s the surprising conclusion of a University of Texas at Austin study which examined how exercise impacted arterial stiffness among 42 sedentary men and women ages 40 to 83. Weight-lifting — whether combined with aerobics or on its own — had little effect on arterial flexibility. The biggest benefit was enjoyed by the so-called “control” group, who were put on a stretching regimen: After 13 weeks, the stretching group increased arterial flexibility by 23%. “Although this particular finding is rather surprising,” observe the study authors, “stretching may be capable of modifying arterial compliance [stiffness].” Possible explanations: Stretching increases the collagen and elastin content of artery walls — and has also been found to help lower blood pressure (chronic high blood pressure contributes to artery hardening).

While further research is needed to confirm these findings, other larger studies have linked poor flexibility with arterial stiffening. Stretching offers a multitude of other benefits: Stretching may reduce post-exercise soreness by as much as 23%, while also protecting against muscle/tendon injury. You’ll get plenty of stretching with yoga, a practice found to ease hot flash symptoms by 31% and help curb middle-age weight gain.

Bonus: The age-old debate — stretch before exercise, or after? After! Stretching before exercise may impair various aspects of athletic performance, decreasing running speed and even hindering heavy lifting. Warm up with repetitive movements that mirror the exercise you’ll be doing.