You’ve probably noticed it during your last few races.

The younger runners who used to struggle to keep up with you are now pulling ahead in the final miles.

Your recovery takes twice as long as it used to, and that spring in your step feels more like a trudge.

Here’s what most runners don’t realize: research shows that NAD+ levels decline significantly with aging, with a notable drop in the 40-49 years age group.

By the time you reach middle age, levels of NAD+ have fallen to half of what they were in your 20s and 30s.

And while that sounds scary, I am sure you’re asking yourself “what the heck is NAD+ and why does it matter?”

Well, that’s what we’re going to dive deep into in this article. You’ll learn…

• Get into detail about what NAD+ actually is (without all the science jargon)
• Show you the research on exactly how this affects your mitochondria, energy production, and recovery ability
• Explain why some “older” runners seem immune to age-related decline (spoiler: they’re not genetically gifted)
• Give you the specific protocol that elite masters athletes are using to reverse this cellular aging

What NAD+ Actually Is (Without the Science Jargon)

NAD+ (nicotinamide adenine dinucleotide) is an essential coenzyme. And if you’re not familiar, coenzymes are like “helpers” that aid in various processes in the body.

In the case of NAD+, it helps other enzymes regulate important functions such as your metabolism, longevity, DNA repair, and the immune system.

NAD+ is also needed for cells to respond appropriately to metabolic stress and repair damage, both of which are needed for maintaining proper tissue function and health.

In essence, NAD+ like your cellular engine’s spark plug.

Just as a car needs spark plugs to ignite fuel, your muscles need NAD+ to convert food into the energy that powers your runs.

NAD+ is found in every cell in your body and is essential to the chemistry that keeps you up and running.

But unlike a car’s spark plugs that last for years, your cellular NAD+ is constantly being used up and needs continuous replenishment.

Aging and the decline of NAD+

Studies show that NAD+ levels peak during our early 20s and then begin a steady decline, with most people experiencing a 40-50% drop by age 50 [3].

A large-scale study published in Frontiers in Endocrinology found that the most significant decline in NAD+ levels occur between the ages of 40-49 years old, with about half the decline in NAD+ levels occurring during these years [1].

From this data, we can see that once NAD+ start to decline, it’s not gradual – it’s dramatic.

By age 50, most people’s NAD+ levels are half of what they were at age 20. The decline accelerates from there.

Why This Destroys Your Running Performance

Okay, so we know our NAD+ levels are declining, especially once we hit 40, but why is this important? Specifically, how does it impact running performance?

Research has shown that NAD+ participates in more than 50% of all physiological processes, including mitochondrial biogenesis, cardiovascular protection, neuroprotection, oxidative stress, DNA damage repair, stem cell rejuvenation, and inflammation [4].

That’s a mouthful of complicated process, so in more simple terms…

When NAD+ drops, your mitochondria, the powerhouses of your muscle cells and a critical component to our aerobic ability, literally can’t produce energy efficiently.

What does this mean specifically?

Reduced ATP Production

Mitochondria produce most of the ATP needed for cellular processes.

If they are inefficient, less ATP is generated, directly limiting the energy available for muscle contraction during prolonged activity.

Lower Stamina and Slower Recovery

Less available energy means your body can’t sustain effort for as long, leading to decreased endurance.

Recovery time also increases because the cells need more time to replenish energy stores.

Increased Lactate Buildup

Inefficient mitochondrial function leads to less lactate being oxidized and processed for energy.

This results in a buildup of lactate, which contributes to early fatigue and diminished exercise performance.

Muscle Weakness and Fatigue

The lack of sufficient energy and increased oxidative stress can lead to muscle weakness and general fatigue.

Decreased Mitochondrial Density

Over time, there is a natural decline in the number of mitochondria, especially in muscle tissue.

This reduction in “powerhouses” means less energy is available for movement, directly impacting strength and endurance.

When it’s all said and done, having less efficient mitochondria is like trying to run a high-performance engine on watered-down fuel.

As NAD+ continues declining:

• Energy production drops further
• Recovery time extends dramatically
• Injury risk increases exponentially
• Performance gaps widen at an accelerating rate

Studies of masters athletes show [7] performance declines linearly up to age 70, then accelerates dramatically, with the steepest declines observed in endurance events.

Combating NAD+ Decline: Training and Diet

So we now understand what NAD+ is and why it’s so critical to maintaining your performance as you age, especially since levels naturally decline as we age.

The question remains – what can we do about it?

Why Traditional Training Isn’t Enough

Unfortunately, there’s nothing I’ve come across in the literature that suggests there is anything you can do with your training to mitigate the decline of NAD+.

For sedentary people, increasing exercise and incorporating strength training can help stimulate mitochondrial activity, which can stimulate NAD+ production as the body generates energy.

A recent study from the Netherlands found that [8] NAD+ is one of the most depleted metabolites in the muscle of older adults, but routine exercise seemingly prevented the depletion of NAD+.

But, if you’re reading this article then it’s likely you’re already doing quite a bit of running and (hopefully) strength training. Increasing training volume or intensity beyond your normal progression to compensate for declining NAD+ levels is likely to backfire.

Training harder with compromised cellular machinery is like flooring the accelerator in a car with a failing engine. You’ll just burn out faster.

The good news here is that you are already ahead of the game compared to your non-running friends.

Why Diet Alone isn’t enough to maintain & restore NAD+ levels

The next question we always look at are what diet changes can we make to help boost NAD+ levels.

Sadly, the news here isn’t great either.

The human body doesn’t readily absorb NAD+ from food sources. Instead, it synthesizes NAD+ from precursors like niacin (vitamin B3) and nicotinamide riboside (NR) [9].

The problem is that while some foods contain niacin and riboside, the amounts are often minimal, making it difficult to achieve significant increases in NAD+ levels through diet alone.

The other challenge is that the body uses complex pathways to synthesize, utilize, and recycle NAD+. This basically means that even if you could eat large quantities of these precursors, the body can’t efficiently convert these precursors into NAD+ [10].

In short, diet can influence these pathways by providing necessary building blocks, but it’s not a direct solution for restoring NAD+ levels.

So, Is There a Way to Combat NAD+ Decline

Luckily, in recent years there’s been some groundbreaking research and development on supplements that can directly boost NAD+ levels.

In fact, research has shown that supplementing with NAD+ restores NAD+ levels and prevents age-related physical decline. Even better, supplementation has been shown in some studies to lead to direct improvements in endurance performance.

That’s why smart athletes are now targeting this cellular decline directly through NAD+ supplementation.

So, let’s take a brief look at some of the research in-depth…

Prevents age-associated genetic changes

A study in aging subjects demonstrated that supplementing orally with NAD+ prevented age-associated genetic changes and improved energy metabolism, physical activity, and insulin sensitivity [11].

Reduces Inflammation

A 2019 study in men with an average age of 75 showed that supplementing with up to 1g of NAD+ daily for 21 days increased NAD+ levels in skeletal muscle and reduced levels of inflammatory proteins in the body [12].

Enhances aerobic capacity

Recent clinical research shows [13] nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners in a randomized, double-blind study.

Improves ventilatory threshold

A landmark study found that [14] exercise training combined with NAD+ supplementation improves ventilatory threshold more than training alone, even among healthy young and middle-aged people.

This is just a small sample of the over 17 clinical studies that demonstrate the effectiveness of NAD+ supplementation on aging and performance.

How to Supplement

In terms of dose, clinical trials show doses of 1,000 to 1,200 milligrams daily for 4 to 12 weeks seem to be the most efficacious for athletes.

Research also suggests taking NAD+ at the beginning of your day because circadian research in animals suggests that NAD+ boosting compounds offer better support for metabolic health when taken in the morning.