Scientists Discover How to Build Injury-Proof Tendons

Your tendons might be the secret weapon you never knew you had.

Dr. Keith Baar faced an impossible challenge. The English Institute of Sport asked him to make world-class cyclists stronger without adding any weight. More muscle meant more power, but it also meant extra bulk to haul up hills and through races.

His solution changed how we think about athletic training. Instead of focusing on muscles, Baar turned his attention to tendons, the tough connective tissues that transmit force from muscle to bone. "We have the little motors in our muscles that produce force," explains Baar, a molecular physiologist at UC Davis. "That force has to be transmitted from our muscle to our bone. And that goes through tendons."

To unlock their potential, Baar grew human connective tissue samples in petri dishes and stretched them between bone-like anchors. He pulled and twisted them, testing how they responded to different exercises and nutrients. The research revealed something surprising: we've been training these crucial tissues all wrong.

Most athletes spend hours stretching to prevent injury. But Baar's research shows that passive stretching actually makes tendons more vulnerable. Female gymnasts, who stretch more than almost any other athletes, have the highest rate of Achilles tendon ruptures in NCAA sports.

The problem is that too much stretching inhibits muscles from contracting quickly when you need them most. When you land from a jump without that split-second muscle tension, your tendons absorb all the force alone. That overload leads to tears and ruptures.

The Ripple Effect

Baar's tendon training protocols are spreading across professional sports. The Denver Broncos use them. So do NBA teams and Cirque du Soleil performers. His methods help springy athletes and flexible contortionists alike avoid career-ending injuries.

The key is simple exercises anyone can do. Pogo jumps, where you bounce repeatedly with minimal ground contact, teach tendons to handle force. Long-hold stretches with resistance, where you push back against the stretch instead of relaxing into it, keep tendons from getting stiff and brittle with age.

Healthy tendons need three qualities: stretchiness to absorb force, stiffness to transmit power, and elasticity to recoil like a bungee cord. Think of tendon fibers like hair in a ponytail, gliding smoothly past each other. Without proper training, they clump together like dreadlocks, becoming vulnerable to pulls and tears.

The beauty of tendon training is that it makes you simultaneously stronger and more resilient. While muscles are the contestants in a tug-of-war, tendons are the rope. A better rope means more power transferred and fewer injuries holding you back.

These discoveries prove that the most powerful performance gains sometimes come from the parts of our body we can't see or feel working.