Gabrielle Lyon, DO, Explains The 3 Ways Muscle Protects Longevity
For decades, muscle has been framed as something aesthetic: a way to look toned, lean, or athletic. But that narrow definition misses the bigger picture.
On a recent episode of the mindbodygreen podcast, Gabrielle Lyon, D.O., argues that skeletal muscle is far more than a visual marker of fitness. It’s one of the most powerful drivers of longevity, metabolic health, and independence across the lifespan.
Lyon is a fellowship-trained physician, New York Times bestselling author, and a pioneer of muscle-centric medicine, an approach that treats muscle as a vital organ system rather than a cosmetic goal. Her message is simple: strength isn’t optional. It’s a responsibility. And when we build muscle with intention, we’re not just investing in today’s workouts; we’re shaping how we age, move, and function for decades to come.
According to Lyon, part of the confusion around muscle comes from the assumption that it serves a single purpose. In reality, skeletal muscle supports longevity in three distinct ways, and most people are only training for one of them.
The three buckets of muscle health
When Lyon thinks about skeletal muscle, she thinks in buckets. Each bucket represents a different function muscle serves in the body, and together they explain why strength training has such far-reaching effects on health.
Bucket 1: Metabolic health
The first and most overlooked role of muscle is metabolic. Skeletal muscle is the primary site for glucose disposal, meaning it’s where carbohydrates are taken up and used for energy. The more healthy muscle tissue you have, the more efficiently your body can manage blood sugar.
This is why many metabolic diseases don’t start in the liver or pancreas, but in the muscle itself. When muscle becomes inactive or infiltrated with fat, its ability to clear glucose declines, setting the stage for insulin resistance and metabolic dysfunction.
Resistance training and regular movement help keep muscle metabolically “active,” improving how the body processes carbohydrates and fuels daily life.
Bucket 2: The body’s “plumbing” system
Muscle also plays a critical role in what Lyon describes as the body’s plumbing—your cardiovascular and vascular systems. Training muscle doesn’t just strengthen limbs; it supports blood flow, vascular function, and overall circulation.
Emerging research underscores this connection. Lyon points to recent findings1 linking greater muscle mass and strength with improved sexual function, a marker often associated with healthy blood vessels and cardiovascular resilience.
In other words, muscle health reflects how well your circulatory system is functioning, making strength training relevant far beyond the gym.
Bucket 3: Strength & mass
The third bucket is the one most people recognize: building muscle mass and strength. This includes hypertrophy, increasing the size of muscle fibers, and developing force production through resistance training.
While aesthetics often get the spotlight here, this bucket is about much more than appearance. Strength and mass support mobility, bone density, balance, and the ability to perform daily tasks as you age. Importantly, strength and hypertrophy exist on a continuum. You don’t need to choose one over the other; both contribute to long-term resilience.
Why aesthetics-only training falls short
Many fitness routines prioritize visible results while overlooking muscle’s metabolic and vascular roles. When training is focused solely on appearance, two-thirds of muscle’s longevity benefits are left untapped.
Lyon emphasizes that all three buckets matter. Training muscle for health means programming workouts that challenge strength, support metabolic demand, and promote overall tissue quality. This doesn’t require extreme routines or constant heavy lifting, but it does require consistency, progressive challenge, and adequate recovery.
Nutrition matters here, too. Eating for strength, especially prioritizing sufficient dietary protein, provides the building blocks muscle needs to adapt and repair. Without that foundation, even the best training plan falls short.
How to train for all three buckets
- Include resistance training at least two days per week to stimulate strength and muscle mass
- Incorporate full-body movements that challenge large muscle groups and elevate metabolic demand
- Stay physically active outside of workouts to keep muscle metabolically engaged
- Fuel with enough high-quality protein to support repair and adaptation
The takeaway
Muscle isn’t just something you build for today’s workouts or tomorrow’s reflection in the mirror. It’s an organ system that protects your metabolism, supports your heart and circulation, and preserves your ability to move independently as you age.
When strength becomes a non-negotiable part of how you train and eat, longevity stops being abstract and starts becoming something you actively build—one rep, one meal, and one habit at a time.