Exercise and Yoga for Sperm Health: Only One Has Numbers

The best single measurement says yes, on two of the four parameters. In the Rochester Young Men's Study, a cohort of n = 189 men aged 18 to 22, sperm concentration was 73% higher (95% CI 15% to 160%) in the highest quartile of moderate-to-vigorous activity -- 15 hours a week or more -- versus the lowest quartile, under 5 hours. Total sperm count tracked activity the same way.

Motility and morphology did not differ at all. And this was a cross-sectional study of young men, not a trial, so it cannot prove that taking up exercise raises anyone's count. It shows that the active men in that group had better counts.

The one randomised setting where semen was measured is weight loss rather than exercise itself: 56 men with obesity lost a mean 16.5 kg on an 8-week diet and sperm concentration rose 1.49-fold (randomised trial, 95% CI 1.18 to 1.88). Exercise appeared there as one of the strategies that held the improvement for a year.

The weight route is covered in more detail on the weight and male fertility page.

The quartiles in that study are the closest thing to a dose that has been measured. The top group did 15 hours a week or more of moderate-to-vigorous activity; the bottom group did under 5. Activity was recorded over the previous three months, which is roughly one cycle of sperm production.

Sitting was measured as a separate exposure and behaved separately. In the same cohort, sperm concentration was 44% lower (95% CI 15% to 63%) in men watching over 20 hours of television, video or DVD a week versus men watching none. So the two are worth changing independently: doing more, and sitting less, are not the same lever.

Nothing retrievable sets an upper limit. The claim that heavy training volumes suppress testosterone or sperm output is widely printed and was not retrievable for this page, so no threshold is given here.

About three months. A cycle of sperm production was measured directly in 11 men who drank labelled water for three weeks: labelled sperm appeared in the ejaculate after 64 plus or minus 8 days, with a range of 42 to 76 days.

NICE NG257 sets the same clock for the test. Recommendation 1.17.4 says to undertake repeat confirmatory semen tests “ideally 3 months after the initial analysis to allow time for the cycle of spermatozoa formation to be completed”. There is one exception in the same recommendation: if a gross deficiency has been found -- azoospermia or severe oligozoospermia -- the repeat should be done as soon as possible, not in three months.

That matters practically. Changing your activity and retesting at three months is a reasonable plan. Changing your activity instead of being investigated is not, because NG257 1.17.5 says that two or more abnormal analyses should lead to a physical examination of the scrotum and testes and consideration of serum testosterone and gonadotrophin measurement. See how to read a semen analysis report for what the parameters mean.

Not in men. No source retrieved for this page measures yoga against sperm concentration, count, motility, morphology or conception in men. That is not a finding of no effect. It is an absence of any measurement to report.

What exists sits one step away, in psychological outcomes and mostly in women having IVF. Cochrane reviewed psychological and educational interventions across 39 randomised studies and 4,925 participants and declined to pool them at all, judging that a combined figure would not be clinically meaningful. Only two of the 39 reported live birth and one reported ongoing pregnancy. Cochrane's stated conclusion is that the effect on live birth or ongoing pregnancy is uncertain on very low quality evidence -- which is a different statement from “it does not work”.

NICE puts the same thing as a recommendation. NG257 1.14.1: inform people concerned about their fertility “that the effectiveness of complementary therapies for fertility problems has not been properly evaluated, and that further research is needed before such interventions can be recommended”.

A 2022 review in a nursing journal gathered 24 yoga and infertility studies, 12 of them from India, and reported positive effects on stress, anxiety and pregnancy outcomes. It is worth naming because it is the source most often quoted back at Indian readers. It pooled nothing, rated no certainty, and almost none of its studies involved men. It does not override Cochrane. The full comparison of stress evidence is on the stress and fertility page.

Nobody has measured that. The question has been asked in the other direction -- whether stress lowers semen parameters -- and in whether distress predicts treatment outcome, and neither answers whether deliberately lowering stress raises anything.

On treatment outcome, the pooled prospective evidence is reassuring and it is in women. Across 14 studies, pretreatment anxiety or depression showed no association with achieving pregnancy after a cycle (standardised mean difference -0.04, 95% CI -0.11 to 0.03; n = 3,583 women). The authors wrote that this should reassure women and doctors that emotional distress will not compromise the chance of becoming pregnant.

So if yoga is being sold to you as a way to remove a stress barrier to conception, the barrier it is removing has not been shown to exist.

Anabolic androgenic steroids are the clearest measured effect on this page, and it points the wrong way. A systematic review of 33 studies and 3,879 participants pooled the men who had hormones measured before and during use: endogenous testosterone fell by 10.75 nmol/L versus baseline (95% CI -15.01 to -6.49, n = 59), luteinising hormone by 3.37 IU/L and follicle-stimulating hormone by 1.73 IU/L (n = 65).

Stopping does not immediately undo it. Gonadotrophins returned towards baseline within 13 to 24 weeks, but testosterone stayed below baseline (-9.40 nmol/L, 95% CI -14.38 to -4.42, n = 27) and was still reduced 16 weeks after discontinuation. The review also records structural and functional sperm changes and reduced testicular volume.

NG257 1.13.1 lists anabolic steroids, alongside testosterone-replacement therapy, among the drugs a clinician should ask about in anyone concerned about their fertility. If you are taking either, say so before any investigation, because it changes how the results are read. See what testosterone therapy costs fertility.

1. Do more of the thing that was measured -- moderate-to-vigorous activity, at the sort of volume that top quartile was doing -- and cut screen-sitting, which was measured separately and went the other way.
2. If your BMI is 30 or over, NG257 1.9.3 records that this carries an increased risk of reduced fertility, and weight loss is the only route with randomised semen data behind it.
3. Retest at about three months, not sooner, unless the first analysis showed azoospermia or severe oligozoospermia, in which case NG257 1.17.4 says repeat it as soon as possible.
4. Do not substitute any of this for the work-up. Two abnormal analyses should lead to examination and hormone measurement under NG257 1.17.5, and time spent training is time in which an actual cause goes unfound.
5. Do yoga if you want to. It is low-risk, it is not a fertility treatment, and paying for a fertility-yoga programme competes with a treatment budget that is already heavy in India.

Stated plainly, because the opposite of each of these is printed widely and appeared on the earlier version of this page:

• That yoga poses improve sperm production. No retrieved source measures any asana against any semen parameter in men.
• That yoga increases blood flow to the testes, or that pelvic blood flow is a lever on semen quality. Neither was measured in anything retrieved.
• That yoga lowers cortisol in a way that changes fertility. The cortisol link is asserted rather than measured; salivary cortisol showed no association with fecundability in either study that measured it.
• That there is a training volume above which testosterone or sperm output falls. Widely claimed, not retrievable, and therefore not given a number here.
• That weightlifting raises testosterone enough to matter for fertility. Not retrievable.
• That cycling harms fertility. Not retrievable. NG257 1.11.1 records an association between elevated scrotal temperature and reduced semen quality but says it is uncertain whether even changing to loose-fitting underwear improves fertility, so the better-studied version of the heat question is itself unresolved.
• That exercise causes the higher counts. The 73% finding is a cross-sectional comparison of quartiles within one cohort of 189 young men. The authors call it an association.
• That any of this raises the chance of a pregnancy. Sperm concentration is a proxy. No retrieved study followed exercise or yoga through to a live birth.

Between appointments there is very little to do and a great deal to think about, and that is most of why fertility yoga exists. Wanting something to do in the waiting is a real reason, and it is a different thing from a fertility claim. Exercise happens to have numbers behind it as well, which is the only reason this page separates the two.