When most people think about metabolic health, they think about calories, carbohydrates, body weight, or how much cardio they are doing.
But there is another important piece of the equation that often gets overlooked: muscle.
As we age, maintaining muscle mass and strength becomes increasingly important—not just for mobility, performance and independence, but also for the way our bodies handle glucose.
Your Muscles Are a Major Part of Your Metabolism
Skeletal muscle is the largest organ in the body by mass and plays a central role in maintaining healthy blood glucose levels. In fact, research indicates that skeletal muscle is responsible for approximately 80% of insulin-mediated glucose disposal under conditions of increased insulin availability.
Why does that matter?
When you eat carbohydrates, they are broken down into glucose and released into your bloodstream. Insulin helps signal your cells to take up that glucose. Your skeletal muscles are one of the most important destinations for that glucose.
Think of your muscles as a major metabolic reservoir: when your muscles are active and responsive to insulin, they can take up glucose and use it for energy or store it as glycogen.
When insulin sensitivity is impaired, however, the process becomes less efficient. Insulin resistance—particularly in skeletal muscle—is a major component of the metabolic dysfunction associated with type 2 diabetes.
Muscle and Insulin Sensitivity: Use It or Lose Some of It
One of the most powerful things about skeletal muscle is that exercise can increase glucose uptake even through pathways that don't depend entirely on insulin.
When your muscles contract during physical activity, they stimulate glucose transport into muscle cells. Research has found that exercise can substantially increase glucose uptake by skeletal muscle, including in people with insulin resistance.
Even a single exercise session can improve skeletal-muscle and whole-body insulin sensitivity for as long as 24–48 hours, according to research reviewing the physiological response to exercise.
This helps explain why physical activity is such an important component of metabolic health.
The landmark Diabetes Prevention Program, a randomized clinical trial involving more than 3,000 adults with elevated risk of type 2 diabetes, found that an intensive lifestyle intervention emphasizing physical activity and weight management reduced the incidence of type 2 diabetes by 58% over approximately three years compared with placebo.
The takeaway isn't simply "exercise more."
It is that your muscles are metabolically active tissue—and keeping them active matters.
What Happens to Muscle as We Age?
Muscle loss is a normal part of aging, although the timing and rate vary from person to person.
Research examining age-related changes in muscle has found that muscle mass generally declines with advancing age, while strength can decline even faster.
This is why maintaining muscle shouldn't be viewed solely as a goal for athletes or bodybuilders.
Muscle health is part of metabolic health.
Resistance training, regular physical activity, adequate protein intake and proper nutrition can all play important roles in maintaining muscle as we get older.
But there's another nutritional factor worth understanding: essential amino acids.
Essential Amino Acids: The Building Blocks of Muscle
Your body requires nine essential amino acids (EAAs) that it cannot produce on its own. They must come from your diet.
These amino acids provide the raw materials your body needs to build and maintain proteins—including the proteins that make up skeletal muscle.
Among them, leucine plays a particularly important role in stimulating muscle protein synthesis.
Clinical research has demonstrated that essential amino acids can stimulate muscle protein synthesis, and studies in older adults have found that leucine-enriched amino acid intake can increase the muscle's response to nutrition.
In one randomized clinical trial involving healthy older adults, researchers examined 24 weeks of essential amino acid supplementation alongside aerobic exercise. The combination of EAA supplementation and exercise produced improvements in muscle strength, while exercise itself improved walking speed and aerobic capacity.
Other clinical research has similarly shown that leucine supplementation can increase muscle protein synthesis in older adults.
Muscle Health Is Metabolic Health
The connection between muscle and metabolism goes beyond simply building bigger muscles.
Your skeletal muscle is constantly interacting with your body's energy systems. It stores glucose as glycogen, uses glucose during activity and responds to both insulin and muscle contractions to regulate glucose uptake.
That means maintaining muscle throughout adulthood can be an important part of maintaining metabolic health.
Rather than thinking about metabolism as simply:
Calories in → calories out
consider the bigger picture:
Nutrition + movement + muscle + metabolic function
Your body is a complex system, and muscle is one of its most metabolically important tissues.
Building a Better Foundation for Muscle Health
Maintaining muscle as you age starts with the fundamentals:
- 🏋️ Resistance training to challenge and maintain muscle
- 🚶 Regular physical activity to keep muscles active and glucose utilization moving
- 🍗 Adequate dietary protein to provide the amino acids your body needs
- 🧬 Essential amino acids to supply the building blocks required for muscle protein synthesis
- 😴 Recovery and sleep to support the body's ability to adapt
- 🥗 A balanced diet to support overall metabolic health
And this is where nutrition can complement an active lifestyle.
Meet Rejuvenate Muscle Health™
Rejuvenate Muscle Health™ is an easy-to-take, refreshing drink mix formulated with a precise serving of plant-based amino acids plus 1000 IUs of vegan vitamin D3.
Instead of another protein shake or heavy meal, Rejuvenate provides a convenient source of essential amino acids designed to help support your body's muscle-health needs.
Because maintaining muscle isn't only about how you look or how much you can lift.
It's about supporting the tissue that plays a central role in how your body uses glucose, responds to insulin and manages energy.
Your metabolism doesn't start with your next workout.
It starts at the cellular level—with the nutrients your body needs to maintain healthy, active muscle.
Stay Stronger, Longer! With Rejuvenate Muscle Health™.
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