How Nutrition and Body Composition Affect Masters Endurance Athletes

When most triathletes over 40 think about improving performance, their first instinct is usually to train harder. But for masters athletes, nutrition and body composition are

often the real game-changers. How you fuel your body—and the shape it’s in—can determine not just how fast you go, but how long you can keep racing.

The Aging Athlete’s Metabolism

As we age, metabolism naturally slows and muscle mass tends to decline. This makes it easier to gain body fat and harder to maintain lean muscle. That shift matters because muscle isn’t just for strength—it’s your metabolic engine. The more lean mass you preserve, the better your endurance, power, and recovery. For masters athletes, nutrition isn’t just about calories in and calories out. It’s about deliberately fueling to preserve muscle, manage body fat, and keep energy steady.

Body Composition and Performance

Triathlon rewards efficiency. Carrying extra weight—even 5 to 10 pounds—makes running tougher on your joints, slows climbing on the bike, and can increase fatigue late in races. On the flip side, dropping weight too quickly or under-fueling can strip away muscle mass and leave you weaker.

It’s important to understand that weight change—whether loss or gain—can absolutely be accomplished while training, even at higher volumes. However, the formula is more complex for masters athletes. Endurance training itself increases calorie needs and alters how the body partitions nutrients. For example, insufficient fueling can lead to a loss of both fat and lean tissue, while properly timed macronutrients—particularly protein—support fat loss while protecting muscle. Conversely, athletes aiming to increase lean mass may need to eat at a slight calorie surplus while still distributing energy carefully around training sessions.

In short: body composition improvements are possible during active training, but they require a careful balance of training stress, calorie intake, and nutrient timing—not the “eat less, move more” simplicity often promoted.

Recovery, Inflammation, and Hormones

Recovery takes longer as we get older, which makes nutrition even more important. Masters athletes who prioritize anti-inflammatory foods—like fatty fish, leafy greens, berries, and spices such as turmeric—often notice reduced soreness and faster turnaround between workouts. On the other hand, frequent processed foods and added sugars can contribute to inflammation and sluggish recovery.

Hormones also shift with age, especially during perimenopause, menopause, and

andropause. These changes affect how the body handles carbohydrates, repairs tissue, and manages energy. Strategic fueling—especially protein intake around workouts—can help maintain lean muscle and support hormone balance.

Fueling Training Sessions the Right Way

One of the biggest mistakes masters athletes make is under-fueling workouts in the hope of cutting weight. Unfortunately, this often backfires. Training in a low-energy state can lead to poor sessions, stalled progress, and even greater body composition struggles. By fueling properly before and during workouts with a mix of carbs and electrolytes, athletes can train harder, protect lean muscle, and ultimately burn more calories over time.

Health, Longevity, and the Big Picture

Health, Longevity, and the Big Picture

At Keystone Endurance, we believe racing well is only part of the story. Nutrition and body composition aren’t just about looking fit on race day—they’re about staying healthy, strong, and active well into your 60s, 70s, and beyond. Proper fueling supports bone health, immune function, and long-term performance, making triathlon not just a sport, but a lifestyle that keeps you thriving.

And we’re living proof.

• Tricia is training for her next half marathon.

• Coach Chet is preparing for a full Ironman.

We’re not just coaches—we’re still athletes ourselves. Still racing, still competing, still dominating podiums, proving that with the right nutrition and training, masters athletes can keep chasing big goals and enjoying the endurance lifestyle for decades to come.

Final Thoughts

For masters endurance athletes, nutrition and body composition are powerful levers for performance and longevity. Training is important, but if you’re not fueling properly and carrying a composition that supports your goals, you’re leaving potential on the table.

Ready to join us? Let’s build your nutrition and training plan together, so you can not only hit your 2026 goals—but enjoy the process, stay healthy, and prove that age is never a barrier.