NAD+ matters for recovery because muscles use it to turn fuel into energy during exercise and to repair themselves afterwards. Regular training actually raises the body's capacity to recycle NAD+. Small human trials of NAD+ precursors show modest gains in endurance in some groups and no change in others, and no trial has yet tested NAD+ injections for recovery.
This article is for adults who train regularly, whether that means running, lifting, cycling or team sport, and want to know whether NAD+ has a place in their recovery. It explains what exercise does to NAD+, what the human research found and did not find, how to fit a protocol around a training week, and which recovery basics come first.
Educational content, not medical advice. NAD+ is not intended to diagnose, treat, cure or prevent any disease. Speak to a licensed prescriber before starting any injectable protocol, especially if you are pregnant or breastfeeding, have active or historic cancer, atrial fibrillation, a weakened immune system or a transplant, or take regular medication. Persistent pain or unusual fatigue after training should be checked by a doctor or physiotherapist.
What exercise does to NAD+
During effort, working muscle burns glucose and fat at many times its resting rate. NAD+ collects electrons from that fuel and becomes NADH, which the mitochondria use to make ATP. The harder the session, the more of the pool sits temporarily as NADH, and the more work the cell does afterwards to regenerate it.
Recovery adds a second demand. Hard or unfamiliar exercise causes small amounts of muscle damage and oxidative stress. Repair enzymes, including PARPs, consume NAD+ as they fix damaged DNA, and sirtuins use it to switch on the genes that build new mitochondria. So the same pool is drawn on twice: once to fuel the session, and again to rebuild after it. Our explainer What is NAD+ covers those enzymes in more detail.
In a well-rested, well-fed person, that is the normal rhythm of training, and the pool refills. The margin narrows when demand stacks up: back-to-back hard sessions, short sleep, a heavy work week, alcohol, or simply being older, since NAD+ levels fall through adult life.
Training itself raises NAD+ capacity
The most consistent finding in this area is one that has nothing to do with supplements. Regular exercise makes muscle better at recycling NAD+.
The key enzyme is NAMPT, which runs the salvage pathway that rebuilds NAD+ from its breakdown products. A 2010 study in the American Journal of Physiology found NAMPT levels in human muscle were higher in trained athletes than in sedentary people, and rose after a few weeks of exercise training. A 2019 study in Physiological Reports found that older adults had lower NAMPT and NAD+ salvage capacity in muscle than younger adults, and that both aerobic and resistance training reversed much of that gap. A 2020 trial in Aging reported that ten weeks of resistance training raised muscle NAD+ and NAMPT in untrained, middle-aged adults.
That matters for how to think about NAD+ and recovery. Training is already the most reliable way to support the system. A protocol is, at most, a way of topping up the pool during periods when demand outpaces supply. It is not a replacement for the training adaptation itself.
What the human trials show
Most trials have used the oral precursors nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), not NAD+ itself. They reliably raise NAD+ in blood. Their effect on performance and recovery depends a great deal on who was studied.
| Study | Who and what | Performance or recovery finding |
|---|---|---|
| Liao et al., 2021 | 48 amateur runners; NMN 300 to 1200mg a day for 6 weeks, alongside training | Aerobic capacity at the ventilatory threshold improved more in the higher-dose groups than with placebo. |
| Igarashi et al., 2022 | 42 healthy men aged 65 and over; NMN 250mg a day for 12 weeks | Blood NAD+ rose. Some measures of muscle function, including walking speed, improved; others did not. |
| Elhassan et al., 2019 | 12 men aged around 70 to 80; NR 1000mg a day for 21 days | NAD+ metabolites in muscle rose and inflammatory markers fell. No change in muscle mitochondrial function. |
| Dollerup et al., 2018 | 40 sedentary men with obesity; NR 2000mg a day for 12 weeks | Well tolerated. No improvement in muscle mitochondrial respiration. |
| Remie et al., 2020 | 13 sedentary adults with overweight or obesity; NR 1000mg a day for 6 weeks | No change in muscle mitochondrial function or exercise efficiency. |
The pattern is similar to what we found for NAD+ and general energy. In people who were training, or in older adults, the trials reported small gains. In sedentary groups, NAD+ went up and muscle performance mostly did not. None of these studies measured recovery directly, for example soreness, strength return after a hard session or readiness the following day. They were small, ran for weeks rather than months, and none used injections.
What the research does not show
- No trial of NAD+ injections for recovery. Subcutaneous NAD+ is well tolerated, and a 2019 infusion study in Frontiers in Aging Neuroscience confirmed that delivered NAD+ is taken up by tissue. But no placebo-controlled trial has tested injections on soreness, strength or training readiness.
- No evidence of a direct performance boost. NAD+ is not a stimulant and does not act on muscle the way caffeine or creatine do. It will not add weight to the bar on the day.
- No evidence it heals injuries. Strains, tendon problems and joint pain need rest, assessment and rehabilitation. NAD+ has not been shown to speed any of them up.
- No head-to-head comparison of formats. Nobody has tested whether injections help recovery more than capsules. Injections deliver more NAD+ itself, with subcutaneous bioavailability above 90%, but that is a pharmacological point, not a proven difference in outcome.
The 2021 review in Nature Reviews Molecular Cell Biology sums up the field fairly: the biology linking NAD+ to muscle and mitochondria is strong, and the human outcome data are still catching up.
The recovery basics that come first
If recovery is the goal, the evidence for the fundamentals is far stronger than for anything in a vial or cartridge. NAD+ only makes sense once these are in place.
| Recovery lever | What it does | Strength of human evidence |
|---|---|---|
| Sleep (7 to 9 hours) | Most muscle repair and hormonal recovery happen overnight | Strong |
| Protein through the day | Supplies the amino acids that rebuild muscle fibres | Strong |
| Carbohydrate after hard sessions | Refills muscle glycogen for the next session | Strong |
| Planned easy days and deload weeks | Gives tissue time to adapt rather than accumulate fatigue | Strong |
| Fluids and electrolytes | Restores what is lost in sweat | Moderate to strong |
| NAD+ (precursors or injections) | Supports the energy and repair pathways that recovery draws on | Early and mixed |
Sleep deserves a special mention, because it is also when the circadian system resets many NAD+-dependent processes. We cover that link in NAD+ for sleep and jet lag.
How to fit NAD+ around a training week
The protocol is the same as for anyone else. There is no evidence that athletes need more, and doubling up after a hard session is not a sensible shortcut.
- Dose: 50mg per injection, which is 0.3ml or 30 clicks on the pen, or 25 units on a U-100 syringe from the vial. A gentler 25mg start (0.15ml, 15 clicks) is an option for the first one or two doses.
- Days 1 to 3: once a day.
- From day 4: every other day, three or four times a week.
- After the first month, if it suits you: twice a week as maintenance.
- Limits without a prescriber: no more than 100mg per injection or 500mg per week.
On timing, there is no trial comparing doses before and after training, so this is practical advice rather than evidence. Most people inject in the morning after a light breakfast. A few people feel brief warmth, flushing or mild nausea after a dose, which is more likely on an empty stomach, so it is worth avoiding an injection in the hour before a hard session or a race. Many people who train find it easiest to line injections up with rest days or easier days, which keeps the every-other-day rhythm simple. Our guide to NAD+ side effects explains how to keep those reactions mild, and the dosage calculator converts any dose into clicks or syringe units.
Rotate injection sites between the abdomen and thighs. If you train legs hard, the abdomen is usually more comfortable on those days. The full technique is in how to inject NAD+ at home.
What people who train tend to notice
Because NAD+ supports a process rather than triggering one, changes are gradual and easy to confuse with normal variation in training. Based on what customers tell us, and consistent with the mechanism, a realistic picture is:
- First week. Mostly nothing, or slightly better sleep. This is normal.
- Weeks two to four. The most common reports are feeling less flat the day after a hard session and handling a busy training week with fewer heavy-legged days.
- Beyond a month. Any benefit depends on consistency, and on sleep and nutrition being in order.
To judge it fairly, keep the rest of your training steady for the first month and note a few simple markers: morning resting heart rate, how heavy your legs feel on a scale of 1 to 10, and whether planned sessions feel harder or easier than usual. Changing your programme, diet and NAD+ at the same time makes it impossible to tell what helped. Think of it as restoring a resource your cells draw on, not as adding a new one.
A note for tested athletes
If you compete in a sport with anti-doping testing, check before you start. The World Anti-Doping Agency's Prohibited List restricts intravenous infusions or injections of more than 100ml in a 12-hour period, whatever the substance, which is one reason IV drips can be a problem for tested athletes. A 0.3ml subcutaneous dose is far below that volume, but the list is updated every year and rules can vary by sport. Check the current list with your governing body or UK Anti-Doping before using any injectable product. The complete UK guide to NAD+ injections covers general safety and who should not use NAD+.
Which kit to try alongside training
- Want to see how you respond first: the NAD+ Trial Kit includes the pen and one 500mg cartridge, ten doses or about two weeks.
- Want a fair test across a training block: the NAD+ Discovery Kit includes the pen and two 500mg cartridges, roughly five weeks at the usual rhythm, which is long enough to cover a typical four-week block.
Both are pre-mixed and third-party verified at 99.5% purity. Delivery is free across the UK, and subscriptions can be paused or cancelled at any time. The full range is in the NAD+ collection.
Frequently asked questions
Does NAD+ help muscle recovery?
It may support it, but the evidence is limited. Muscles use NAD+ to make energy and to repair after exercise, and small trials of NMN found modest endurance gains in runners and older adults. No trial has measured recovery itself with NAD+ injections.
Should I inject NAD+ before or after a workout?
There is no trial comparing the two. Most people inject in the morning after a light breakfast, and many line doses up with rest or easy days. Avoid injecting in the hour before a hard session, in case of brief flushing or nausea.
Can athletes use NAD+ injections?
Many recreational athletes do. Tested athletes should check the current World Anti-Doping Agency list and their governing body first, because injections or infusions above 100ml in 12 hours are restricted regardless of the substance.
Do I need a higher dose if I train a lot?
No. There is no evidence that people who train need more than the usual 50mg every other day. Keep to no more than 100mg per injection and 500mg per week unless a prescriber advises otherwise.
Does exercise increase NAD+ on its own?
Yes. Human studies show regular aerobic and resistance training raises NAMPT, the enzyme that recycles NAD+, and increases NAD+ in muscle, including in older and previously untrained adults.
Is NAD+ better than creatine or protein for recovery?
They are not comparable. Protein and creatine have far stronger evidence for muscle recovery and strength. NAD+ supports energy and repair pathways more broadly and, if used at all, sits on top of good sleep and nutrition.
Sources
- Costford SR et al. Skeletal muscle NAMPT is induced by exercise in humans. American Journal of Physiology: Endocrinology and Metabolism, 2010.
- de Guia RM et al. Aerobic and resistance exercise training reverses age-dependent decline in NAD+ salvage capacity in human skeletal muscle. Physiological Reports, 2019.
- Lamb DA et al. Resistance training increases muscle NAD+ and NADH concentrations as well as NAMPT protein levels and global sirtuin activity in middle-aged, overweight, untrained individuals. Aging, 2020.
- Liao B et al. Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners: a randomized, double-blind study. Journal of the International Society of Sports Nutrition, 2021.
- Igarashi M et al. Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. npj Aging, 2022.
- Elhassan YS et al. Nicotinamide riboside augments the aged human skeletal muscle NAD+ metabolome and induces transcriptomic and anti-inflammatory signatures. Cell Reports, 2019.
- Dollerup OL et al. A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects. American Journal of Clinical Nutrition, 2018.
- Remie CME et al. Nicotinamide riboside supplementation alters body composition and skeletal muscle acetylcarnitine concentrations in healthy obese humans. American Journal of Clinical Nutrition, 2020.
- Covarrubias AJ et al. NAD+ metabolism and its roles in cellular processes during ageing. Nature Reviews Molecular Cell Biology, 2021.
- Grant R et al. A pilot study investigating changes in the human plasma and urine NAD+ metabolome during a 6 hour intravenous infusion of NAD+. Frontiers in Aging Neuroscience, 2019.
