Does NAD+ Support Muscle Function?
NAD+ (nicotinamide adenine dinucleotide) supports a vast range of functions within the human body. NAD+ is a vital component in energy generation. Known commonly as a “coenzyme,” NAD+ works with enzymes to support mitochondrial function.
Mitochondria power your cellular turbines. Think of this organelle as a battery that lives within every cell, powering each cell’s many functions.
Mitochondria use NAD+ to convert sugars, fats, and proteins into the cellular energy we know as adenosine triphosphate or ATP. Muscles use ATP to power voluntary and involuntary movement within the body.
But to understand how NAD+ aids muscle function, you must first understand the way muscles behave.
NAD+ is essential for muscle function and movement.
A recently published study in Skeletal Muscle suggests muscles that support your mobility, like skeletal and cardiac muscles, tend to be “energetically expensive.”
Therefore, movement itself ends up requiring a larger amount of NAD+ relative to “stationary” tissues. A solitary muscle cell often requires thousands of mitochondria to operate, further proving the importance of NAD+ in movement.
The human body has evolved to meet the needs of its various organ systems. As a result, NAD+ is hyper present in muscle cells, and other metabolically active tissues, due to the high number of mitochondria.
How do muscles work?
Muscles perform unique patterns of contraction and relaxation to help the human body function. The involuntary movement supports bodily mechanisms beyond your conscious control.
Cardiac muscles create a heartbeat through repeated, involuntary contraction. And while you can breathe with intention, muscles help your lungs breathe independently, even while you sleep.
Alternatively, voluntary muscle function supports any movement dependent on conscious choice.
From stretching to walking, muscles help you navigate your world. Skeletal muscles, which wrap around your bones, are particularly influenced by voluntary movement.
Your hands cannot operate without your instruction. When you run, your intention drives the speed and intensity of movement in your legs.
All these motions rely on NAD+ to convert macronutrients into ATP, which in turn fuels the contractions.
How are muscle repair and NAD+ connected?
Muscle repair is largely coordinated by nutrient availability, which is particularly necessary during and after exercise.
NAD+ is not just responsible for cells’ utilization of energy. A 2017 review published in Antioxidants and Redox Signaling demonstrates that NAD+ provides cells with key information about nutrient levels, playing a vital role in communicating cellular needs.
NAD+ helps facilitate the conversion of nutrients into energy and is an essential cofactor for cellular repair enzymes. This process ultimately supports muscular regeneration.
Mature muscle cells exhibit signs of high plasticity and can reach full regeneration after an injury.
Muscles are not impervious to damage. Both over-training and inactivity can threaten their structural integrity and health.
To put this in the simplest terms, NAD+ helps muscle cells repair and recover.
The stages of muscle repair.
A recent review published by Thomas Laumonier and Jacques Menetrey has revealed that muscular repair is a three-stage process: destruction, repair, and remodeling.
The destruction phase begins immediately following an injury. After a muscle ruptures or tears, the wounded area fills with blood.
Inflammatory cells flock to the injury, using the blood as its main conduit. Cells centralize inflammatory and healing responses around the injured tissue, protecting any healthy adjacent cells from destruction.
After inflammatory cells complete the destruction phase, repair begins—vital cells called macrophages clear any remaining cellular debris.
Macrophages are responsible for removing dead cells and leftover dried blood from the injury site, paving the way for muscle stem cells called satellite cells to begin healing.
Satellite cells band together to create new muscle fibers, while cells called fibroblasts create a bridge of connective tissue over the torn muscle.
According to a review published in the International Journal of Molecular Sciences, NAD-dependent enzymes called sirtuins are also critical for muscle repair. In response to physical stimulation, sirtuins activate and trigger mitochondrial biogenesis, the process of cellular reproduction.
As satellite cells and fibroblasts mature, they transform into scar tissue.
While scar tissue eventually fully transitions into muscle, its formation from the repair phase is structurally different from muscle itself.
Physical therapy and careful movement can help correct these differences. Bodywork can help detangle clumps of scar tissue to help it align with the stripe-like structure of healthy muscle.
All these cells depend on energy from their mitochondria to facilitate these three stages. A clinical study published in Muscle, Ligaments, and Tendons Journal showed that the severity of a muscular injury determines the energy and time needed to heal.
Remodeling is the primary mechanism that supports the growth of muscle mass, according to a review published in Antioxidants and Redox Signaling.
As you exercise, macrophages, satellite cells, and fibroblasts undergo the same repair process at a smaller scale. Without a large tear to heal, new tissue mimics the parallel structure of existing muscle fibers, creating bigger and stronger muscles.
Rest builds muscle.
Muscle function and the availability of NAD+ follow an energetic pattern known as circadian rhythm. The circadian rhythm controls sleep-wake cycles and “is involved in many important aspects of muscle physiology,” according to a review recently published from F1000 Research.
Rest is essential for repair, especially for muscles. It allows your body to repair any site of injury, without risking further, energy-draining damage.
Mindful exercise, paired with plenty of rest, builds healthy, energized muscles. Listen to your body and create an intuitive exercise regimen that benefits your health in the future.