How overtraining can lower libido, and what the research shows

Exercise is good for your sex life, on average. But there is a real edge case that gets ignored: train too much, fuel too little, and sleep too little, and libido is often one of the first things to quietly disappear. This is not a moral failing or a mystery. It is your body triaging energy, and the research on it is clearer than most people realise.

The short version

For most people, exercise helps libido. This is about the opposite extreme: too much training with too little recovery.
The root cause is usually low energy availability, not enough fuel for the training you are doing.
In men, very high endurance loads are linked to lower testosterone, a pattern researchers call the exercise hypogonadal condition.
In women, underfuelling can disrupt periods and hormones, part of what sports medicine calls relative energy deficiency in sport (RED-S).
The fix is almost always to eat more, rest more, and train a little less, not to add supplements.

The overtraining paradox

Start from the honest baseline: regular exercise is one of the better things you can do for your sex life. It improves blood flow, mood, body image, and energy. So this article is not an argument against training. It is about a specific edge that dedicated people can wander over without noticing.

That edge is overtraining: chronically doing more hard training than you recover from, usually while not eating enough to cover it. Cross it and the body does something sensible from a survival standpoint. It starts switching off systems it deems non essential in a time of scarcity. Reproduction and sex drive are near the top of that list.

The core idea

Your body reads heavy training plus not enough food as a signal that times are hard. When resources feel scarce, it deprioritises reproduction. Lower libido is a downstream sign of that budgeting, not a random glitch.

The real driver: low energy availability

The concept that ties this together is energy availability: the fuel left over for your body's basic running costs after exercise has taken its share. Train hard and eat plenty, and availability stays high. Train hard and undereat, even without meaning to, and availability drops. Push it low enough for long enough and hormones start to shift.

This is why the problem clusters in endurance athletes, people in weight sensitive sports, and anyone stacking a demanding training block on top of a busy, under fuelled life. It is often not deliberate dieting. It is simply not eating enough to match a heavy training load, week after week.

Common mistake

Assuming a fading sex drive means you need a testosterone or libido supplement. In this situation the deficit is usually energy and recovery, not a nutrient. Supplements do not fix a body that is simply being run at a loss.

What the research shows in men

In men, researchers have described the exercise hypogonadal pattern: some men doing very high volume endurance training show persistently lower resting testosterone. Reviews report levels in affected men that are roughly 50 to 85 percent of matched, less active men.

The honest nuance matters here. Lower testosterone is linked with lower libido on average, but studies on these athletes have not cleanly proven that the lower testosterone alone causes their lower sex drive. Fatigue, stress, and simply being exhausted plausibly do a lot of the work too. In real life these all arrive together, which is rather the point.

What this does not mean

This is not a reason to train less if you are a normal recreational exerciser. The men in these studies are doing very large training volumes. Moderate exercise is associated with better sexual function, not worse.

What the research shows in women

In women, the clearest signal of running at an energy deficit is a change to the menstrual cycle: lighter, irregular, or absent periods. This is part of what sports medicine now groups under relative energy deficiency in sport (RED-S), where too little fuel disrupts hormones across many body systems, not just reproduction.

The International Olympic Committee's expert consensus on relative energy deficiency in sport lists reduced sex drive among the effects of this state, alongside disrupted periods, low bone density, mood changes, and impaired performance. As with men, the driver is the energy deficit, and the treatment is restoring energy availability, not chasing symptoms one by one.

This is a see-your-doctor sign

Missed or absent periods in someone training hard are not a badge of fitness. They are a medical sign worth taking seriously, because the same energy shortfall can quietly weaken bone. Please raise it with a doctor rather than waiting it out.

Signs you may be over the edge

Low libido rarely arrives alone. It usually travels with other signs that you are asking more of your body than you are giving back. Any cluster of these deserves a rethink of your training and eating.

A noticeable drop in sex drive that tracks with a hard training block
Performance going backwards despite training as hard or harder
Feeling run down, unmotivated, or low more than usual
Poor or restless sleep even when you are exhausted
In women, irregular or missing periods
Getting sick more often or picking up niggling injuries

The reassuring part

This state is usually reversible. When people restore fuel and rest and pull training back, hormones and libido tend to recover. In case reports of athletes with relative energy deficiency, eating more and training less brought things back toward normal.

How to recover

The fixes are unglamorous and they work. This is a general framework, not medical advice for your specific situation, so loop in a doctor or sports dietitian if symptoms persist.

Eat more, especially around training. Close the energy gap. Enough total food, enough carbohydrate to fuel sessions, and enough protein to recover. This is the single biggest lever.
Pull training back for a while. A lighter block or a proper deload week lets your body climb out of deficit. Less is genuinely more here.
Protect sleep. Recovery and hormones both run largely on sleep. Aim for a consistent, adequate amount before reaching for anything fancier.
Look at life stress too. Training is only one stressor. Work and life stress add to the same load your body is trying to manage.
See a doctor if it does not lift. Persistent low libido, missed periods, or low mood deserve a proper look. There are other causes worth ruling out, and help is available.

Questions people ask

Does exercise lower or raise libido?

For most people, regular moderate exercise raises it by improving blood flow, mood, and energy. Libido only tends to fall at the extreme of chronic overtraining combined with not eating enough, where the body reacts to a sustained energy shortfall. The problem is the deficit, not exercise itself.

Can too much cardio lower testosterone?

Very high endurance training volumes are linked with lower resting testosterone in some men, a pattern researchers call the exercise hypogonadal condition, with levels reported around 50 to 85 percent of less active men. This is about extreme loads. Moderate cardio does not have this effect and is good for sexual health.

Will a testosterone or libido supplement fix this?

Usually not, because the underlying issue is an energy and recovery deficit rather than a missing nutrient. The reliable fix is eating more, resting more, and training a little less. If low libido persists after you restore fuel and rest, see a doctor to look for other causes.

How long does it take for libido to come back?

It varies, but when the cause is overtraining and underfuelling, many people notice improvement within weeks of restoring energy and cutting training back. If there is no change after a sustained period of eating and resting more, that is a reason to get checked rather than to keep waiting.

References

Hackney AC, Hackney ZC. Current Trends in Endocrinology. The exercise-hypogonadal male condition and endurance exercise training. 2005. pmc.ncbi.nlm.nih.gov/articles/PMC6853631
Mountjoy M, et al. British Journal of Sports Medicine. 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). 2023. doi.org/10.1136/bjsports-2023-106994
Hackney AC. Frontiers in Endocrinology. Hypogonadism in Exercising Males: Dysfunction or Adaptive-Regulatory Adjustment?. 2020. doi.org/10.3389/fendo.2020.00011
U.S. Department of Health and Human Services. Physical Activity Guidelines for Americans, 2nd edition. 2018. health.gov/paguidelines/second-edition

Last reviewed 18 July 2026. We check health-condition articles against current guidelines and update the date above when we do.