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IF YOU’RE AN NBA fan, you’ve likely had your heart broken by a tendon injury. Take, for example, Game 7 of the 2025 finals between the Indiana Pacers and Oklahoma City Thunder. With 4:55 left in the opening quarter, two-time All-Star guard Tyrese Haliburton, then 25, planted his foot just outside the three line, the way he'd planted it a thousand times before—and then he didn't.
“Haliburton’s down! He looks hurt!” the announcer says, a line that hit every fan in the gut. The official report confirmed what the MRI showed: a torn right Achilles. Surgery, eight to 10 months of rehab, and a 2026 season that would effectively end before it could begin. Reports noted that the calf strain had appeared days earlier, a warning the body had been sending before anyone thought to listen. The cause? Nobody said.
Achilles ruptures are more than three times as common in men as in women, and male incidence is rising steadily year over year, according to a 2026 study. The peak age window for injury is 30 to 49, but young athletes—both Haliburton-level and weekend warrior—aren’t immune either. In fact, about 60 percent of ruptures are sport-related. And the guy isn’t usually a pro. He's a recreational athlete. Average age: Nearly 38.
There are recommended treatments for tendon injuries. Rest, obviously. Surgery, commonly. But there’s far less information about tendon injury prevention.
When I followed the sports media noise around Haliburton’s Achilles rupture, I started putting together my experience as a registered dietitian, the emerging research I’d seen bubbling up in scientific journals, and what I’d seen in my own clients who had suffered tendon injuries.
Maybe there’s a key to tendon injury prevention that no one’s talking about.
The Tale of the Tendon
FROM A PHYSIOLOGICAL perspective, tendons are the unsung support network of the body. These dense wiry tissues, connect your muscles to your bones. (An adult has roughly 400 tendons, way more than its 206 bones). And tendons run all over: The Achilles connects your calf to your heel, the patellar tendon from kneecap to shin, the rotator cuff threading through the shoulder, and the hamstring tendons anchoring at the back of the knee.
But tendons aren't passive ropes. They're living metabolic tissue that adapts slowly because it’s built slowly. And when an injury happens, “tendons take longer to recover, longer to adapt; it could take weeks, whereas muscles recover and adapt within 48 hours," says Theresa Lau, DPT, ATC, CSCS, of Evolve Performance and Physical Therapy. Lau has worked with some of Major League Baseball's top athletes, and witnessed tendon recovery taking place in real time.
Tendon damage accumulates quietly, over weeks and months, sometimes before anyone on the medical staff (or the athlete themselves) notices differences in power, recovery, and speed.
"Ninety-five percent of whether your muscle is big or small is down to the exercise. Same thing is true for your tendon. The five percent is what you're doing with the nutritional components," says Keith Baar, PhD, a professor of molecular exercise physiology at the University of California, Davis.
So let’s hit each in that order.
How to Exercise a Tendon
MEN’S HEALTH FITNESS Director Ebenezer Samuel, CSCS, says people think tendon injuries happen during explosive effort. The jump, the sprint, and the lift. But Samuel says tendons actually break on the way down.
"A lot of times the Achilles injury is going to happen when we're in that moment of absorbing force," he says. Most training programs don't take this absorption into account. "What people don't do is spend time repeatedly absorbing a more normal force as opposed to a maximal force."
His prescription comes down to three families of moves that every athlete should have in their week. Heavy eccentrics, like a slow single-leg calf lower, that trains the tendon under a full stretch. Low-level force absorption work, like jump roping, single-leg hops, bounding, the kind of repetitive and rhythmic loading most gym programs don't think about. And explosive depth work, depth jumps, and drop-catch push-ups, trained for quality over volume, where you implement three sets of six at most.
"Making sure all three families are covered throughout the training week," Samuel says, is what most programs are missing entirely.
How to Feed a Tendon
THE SCIENCE CONNECTING metabolic health to tendon injury has been building in recent years. When a tendon is inflamed, the repetitive stress of exercise can create a breaking point. And diet can affect inflammation.
While nutrition and tendon health are still in the very early stages of research, some experts are seeing the connection through their work. Craig Moore, RD, CSCS, a sports dietitian at Red Bull's Athlete Performance Center in Santa Monica, CA, says he’s been aware of the knowledge gap for years. “Yet I've very rarely seen dietitians actually talk about the role cholesterol and blood sugar play in soft tissue health,” he says.
The two key nutrients at play seem to be saturated fat and glucose.
Let's take dietary saturated fat first. This type of fat has been shown to raise LDL cholesterol in the bloodstream by suppressing the liver's ability to clear it. That's a different mechanism from dietary cholesterol, the kind in whole eggs, which barely moves your blood LDL by comparison.
Moore says it’s common for him to have young, healthy athletes eating large amounts of saturated fat because they’ve heard it's good for them. This trend has been fueled by the new Dietary Guidelines for Americans and social media influencers touting beef tallow as an alternative to seed oil.
I, too, have worked with clients who believe diets high in saturated fat don't contribute to cardiovascular disease, even though the evidence consistently links dietary patterns high in saturated fat to heart disease risk. Yes, diets high in saturated fat also tend to be high in sodium, ultra-processed foods, and low in vegetables. So the nutrient isn't the sole driver of high LDL levels, but it's not the bystander either.
Baar points to lab data that shows that palmitate, the dominant fatty acid in saturated fat, found in high amounts in beef and dairy, might be one mechanism. "We've done high-fat diet-fed animals and looked to see what happens in their tendons, and sure enough, their tendon function goes down a little bit, their tendon collagen goes down a little bit,” he says.
Then there’s post-injury nutrition. "There are studies that show if someone has elevated blood cholesterol, it impairs the healing of the tendon after surgery,” says Moore. “So if you have an athlete who is at risk for an Achilles injury and they have elevated blood cholesterol, there’s something to be said for the fact that you're actually not optimizing the internal environment for healing and recovery.”
Elevated blood cholesterol isn't only about diet, though. Genetics, thyroid function, metabolic health, and medications all play a role. But for most active people without an underlying condition, what you're eating is the primary driver and the one variable you can actually change.
Finally there’s glucose, the body's primary fuel source. In the right amounts, glucose circulates through the bloodstream and powers everything from muscle contraction to brain function.
When blood glucose stays elevated, however—like through a lackluster diet, insulin resistance, or early pre-diabetes—the excess starts binding to proteins. That's where tendons become a target.
The process where excess glucose binds to the collagen in your tendons (creating advanced glycation end products, or AGEs) makes the fibers stiffer, more brittle, and far more likely to snap under load. A 2021 study found that athletes with elevated blood sugar faced three times the risk of tendon injury compared to those with normal glucose levels.
Baar sees the same thing from the lab side. "We even do things with individuals with chronic kidney disease, or with diabetes, or with all of these different metabolic problems. Yes, their tendon function is lower."
So if you're an active guy, whether that's pickup ball on weekends or training for your next Hyrox, and you have blood glucose issues or tend to eat a lot of saturated fat, it might be time to make a few changes.
The Stronger-Tendon Protocol
CLINICALLY, WHEN SPORTS dietitians assess soft tissue health, these are the numbers they look at:
A1C below 5.7 percent
Once you cross into pre-diabetic territory, the AGE process accelerates, with glucose binding to collagen fibers in your tendons, making them stiffer and more brittle.
Vitamin D between 40 and 50 ng/mL
Vitamin D plays a direct role in collagen synthesis and soft tissue repair. Foods like fatty fish, egg yolks, and fortified dairy typically deliver 400 to 800 IU per day, well short of what moves the needle. A 1,000 to 2,000 IU D3 supplement daily is the most reliable path, especially fall through spring. Sunlight works too, but only with 15 to 20 minutes of direct skin exposure at midday, not through glass at your local coffee shop and not with SPF higher than 15 on.
Ferritin between 40 and 90 ng/mL for athletes, with nothing below 30
Iron is a required cofactor in collagen synthesis, working alongside vitamin C to give tendons their structural integrity. Low ferritin slows the very process your tendons depend on to rebuild.
Zinc, manganese, copper
The mineral trio is found in pumpkin seeds, oysters, and whole grains—and they all help collagen in some way. Most athletes aren’t tracking or aware of the any of the three in my experience.
And while collagen powder is popular in the athlete space, taking it without addressing vitamin C, D, iron, and key minerals means the raw material shows up with no way to be used. The body cannot build what it cannot process.
And, lastly, watch for performance before you watch for pain. Theresa Lau, who works with Major League Baseball athletes, puts it plainly: The biggest sign of overtraining appears in performance before it leads to an injury.
An unexplained drop in output is often the first signal, so don't wait for the snap.
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Headshot of Dezi Abeyta, RDN
Dezi Abeyta, RDN
Dezi Abeyta, RDN, is a Men’s Health Nutrition Adviser, author of Lose Your Gut Guide, and founder of Foodtalk Nutrition LLC.