Sperm motility is the share of sperm that move, and the WHO's 2021 lower reference limits are 42% for total motility and 30% for progressive motility (sperm swimming forward). The changes with the best evidence for better motility are stopping smoking (smokers' motility was 3.5 percentage points lower in a meta-analysis of 5,865 men), getting to a healthy weight (obese men's progressive motility was about 6 points lower in a meta-analysis of 71,337 men), having a varicocele assessed if a doctor finds one (repair raised motility by about 10 points in a meta-analysis), and keeping the abstinence before a test short (under two days was linked to about 2 points higher progressive motility). Antioxidant supplements have mixed results: small CoQ10 trials show gains, but a rigorous placebo-controlled trial of a multi-antioxidant (MOXI, 174 men) found no effect on motility. Any change takes two to three months to show in a sample, because that is how long new sperm take to form and reach the ejaculate.
What motility means on your report
A semen analysis sorts sperm by how they move. The 2021 WHO manual uses four grades: fast progressive (grade a), slow progressive (grade b), non-progressive (grade c, moving without getting anywhere, such as swimming in tight circles) and immotile (grade d). Your report will usually show two numbers:
- Progressive motility: grades a and b together, the sperm swimming forward. The WHO lower reference limit is 30%.
- Total motility: everything that moves, progressive plus non-progressive. The lower reference limit is 42%.
These limits are the 5th centile of men whose partners conceived within a year, so plenty of men below them still father children. The WHO manual says it directly: "a semen analysis is never prognostic of fertility". Older reports may use the word asthenozoospermia for motility below the limit; the 2021 manual dropped that label. The semen analysis guide covers the rest of the report, and the checker compares your numbers with the limits.
First, check the sample was measured fairly
Motility is the most fragile number on the report, because sperm slow down with time and temperature. The WHO manual asks for 2 to 7 days of abstinence before the sample, for a sample produced at home to reach the lab within 50 minutes (preferably 30), for it to stay between 20 and 37 °C on the way, and for motility to be assessed within an hour of collection. NHS labs give the same instructions: Manchester's Saint Mary's Hospital asks patients to carry the pot in an inside pocket to keep it at body temperature.
A sample that sat in a cold car or took an hour and a half to arrive can read low for reasons unrelated to your sperm. That is one reason the UK's NICE guideline says an abnormal result should be repeated, ideally three months after the first. If your low motility came from a single test, the next step is a second test done carefully, not a conclusion.
Stop smoking
A 2016 meta-analysis in European Urology pooled 20 studies and 5,865 men. Smokers had sperm motility 3.5 percentage points lower than non-smokers, alongside lower counts and poorer morphology, and the gaps were larger in moderate and heavy smokers and in men already being seen for infertility. The UK's NICE guideline notes the association between smoking and reduced semen quality. Vaping has much less evidence either way; the smoking and vaping guide has what exists.
Get to a healthy weight
A 2024 meta-analysis of 50 studies and 71,337 men found obese men had progressive motility about 6 percentage points lower and total motility about 2 points lower than men of normal weight; overweight men's progressive motility was about 3 points lower. NICE links a BMI of 30 or over with reduced fertility in men. If you're muscular, BMI can overstate things, so waist size is a useful second check; the weight guide covers the weight-loss evidence.
Have a varicocele assessed
A varicocele is a set of enlarged veins in the scrotum, found in about 15% of men and 35 to 40% of men seen for infertility. It is thought to affect sperm partly through heat. A 2007 meta-analysis found that microsurgical repair raised sperm concentration by about 9.7 million per mL and motility by about 9.9 percentage points in men with a palpable varicocele and abnormal semen. A 2021 Cochrane review of 48 trials concluded that treatment may improve pregnancy rates, with low-certainty evidence, while the effect on live births is uncertain. This one is for a doctor to examine and decide on, but it is one of the few causes of low motility with a specific treatment.
Keep abstinence short before a test
Longer gaps between ejaculations mean older sperm in the sample. A 2018 review of 30 papers concluded that shorter abstinence periods are "accompanied by a substantial improvement in sperm motility characteristics, especially progressive motility". A 2024 meta-analysis of 22 studies and 31,640 samples found abstinence under two days was linked to progressive motility about 2.2 points higher and lower DNA fragmentation, at the cost of about 0.8 mL less volume and a concentration about 8 million per mL lower. Another systematic review called the evidence contradictory and declined to name an ideal interval. The practical reading: within the lab's 2 to 7 day window, the shorter end (Manchester's NHS lab says 3 or 4 days is best; Leeds asks for 3 to 5) is a sensible target, and when trying to conceive there is no benefit in saving up. The ejaculation frequency guide has the details.
Heat, laptops and phones
Heat to the testes is linked to poorer semen quality, and NICE notes that association while saying it's uncertain whether loose underwear improves fertility. The heat guide covers saunas, hot tubs, laptops and cycling, including how quickly things recovered once the heat stopped.
Phones are genuinely mixed. A 2014 meta-analysis of 10 studies and 1,492 samples found phone exposure was linked to motility about 8 points lower, pooling lab studies that exposed sperm to phone signals with observational studies of phone users. But a large population study of 2,886 young Swiss men, published in 2023, found no consistent link between phone use and motility (heavier use was linked to a somewhat lower concentration, and the association weakened over the years of the study). Keeping your phone out of your front pocket costs nothing, but it isn't where the evidence is strongest.
Drink within the guidelines
NICE's position is that excessive alcohol harms semen quality, while drinking within the UK guideline of 14 units a week, spread across several days, is unlikely to affect it. The alcohol guide covers the dose curve and weekend drinking.
Exercise regularly, but not to extremes
A 2019 meta-analysis of 32 papers concluded that recreational physical activity "seems to be of benefit" for men with infertility issues, while elite-level training could harm semen quality. Moderate, regular exercise is the target. The exercise guide has the details, including cycling.
Supplements: CoQ10 and antioxidants
This is where marketing runs furthest ahead of evidence. The 2022 Cochrane review of antioxidants, 90 trials and 10,303 men, found antioxidants may raise live birth rates, but rated the evidence very low certainty and called it inconclusive because of serious risk of bias; the effect shrank and was no longer statistically significant when studies at high risk of bias were removed. A well-designed multicenter placebo-controlled trial, MOXI (174 men, published 2020), gave men a multi-antioxidant or a placebo for three to six months and found no difference in motility, morphology or DNA fragmentation at three months.
CoQ10 has the most consistent motility signal. A 2013 meta-analysis of three randomized trials found motility improved with CoQ10, and a 2021 systematic review of 24 studies found motility rose in all but one of the 12 studies of CoQ10 on its own, though only 7 of the 24 were randomized placebo-controlled trials. Both noted there is no good evidence it raises pregnancy or live birth rates. If you want to try one supplement for motility, CoQ10 is the one with data, but it is a small, uncertain lever next to the ones above. More in the supplements guide.
Infection and inflammation
The European Association of Urology's guideline notes that chronic prostatitis and pelvic pain syndrome have been linked to lower sperm density, motility and morphology in a systematic review. A high white blood cell count in semen (leukocytospermia, more than 1 million per mL) sometimes shows up on a report, but the guideline says there is no evidence that treating it without a confirmed infection improves the chance of conception. If you have pain, discharge or symptoms of infection, that is a GP visit regardless of fertility.
How much motility matters for getting pregnant
Clinicians often combine motility with count into the total motile sperm count (TMSC): semen volume times concentration times the share of progressively motile sperm. A 2015 study of 1,177 couples followed for three years found TMSC predicted natural conception better than the WHO categories, sorting couples into three groups: under 5 million, 5 to 20 million, and over 20 million. Couples below 5 million had noticeably lower natural pregnancy rates. So a motility figure a little under 30% matters much less if your count is high, and more if it is low; the low sperm count guide covers that side. That is the calculation a fertility specialist will do, and our TMSC calculator does it from your own numbers.
How long it takes to see a change
New sperm take roughly two to two and a half months to form and reach the ejaculate (about 64 to 74 days in the tracer and isotope studies), so any change you make today first shows in a sample two to three months later. That is why NICE recommends repeat tests about three months apart. The 74-day timeline tool gives you the first date a retest can reflect a change you start now.
What to do
- If one test came back low, repeat it, and follow the lab's instructions exactly: 2 to 7 days of abstinence, the pot kept warm, delivered fast.
- Stop smoking. It has the most consistent motility evidence of any habit.
- Work toward a healthy weight, measured by waist as well as BMI.
- Ask your GP to examine for a varicocele if motility is low on two tests.
- Keep drinking within 14 units a week, exercise moderately, and keep heat away from your groin.
- If you want a supplement, CoQ10 has the most motility data. Don't expect much from it.
- Retest after about three months. Motily's 74-day journey is built around exactly that window.
Common questions
What is a normal sperm motility?
The WHO 2021 lower reference limits are 42% total motility and 30% progressive motility. These are the 5th centile of fertile men, so most fertile men sit above them, but a result below them is a reason to retest and investigate rather than a diagnosis.
How fast can sperm motility improve?
A sample produced after a short abstinence can show slightly better motility within days, because the sperm are younger. Changes to habits take two to three months to show, because that is how long new sperm take to form and mature.
Can low motility be cured?
It depends on the cause. A poorly handled sample needs only a careful retest. Smoking, weight and heat are linked to motility and can be changed. A varicocele can be treated. Some causes are genetic or unexplained. A urologist or andrologist can tell you which applies after two tests.
Can I still get my partner pregnant with low motility?
Often, yes. Motility is one input among several; a large study of 1,177 couples found the total number of motile sperm predicted natural conception better than the WHO categories that classify each measure separately. If motility is low, ask your doctor to calculate your total motile sperm count.
Related guides
Sources
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Correction, 8 October 2026. The MOXI trial gave treatment for three to six months and measured results at three months.
