Frequent brisk walks boost fertility in men

*Moderate exercise curbs type of stress that damages sperm

Going for a walk three times a week could help men boost their fertility, research suggests.

Even those who usually do little exercise could improve the quality of their sperm in as little as six months.

Tests showed a range of benefits in men who jogged or walked for 30 minutes three or four times a week. Experts say moderate exercise curbs oxidative stress, which damages sperm.

One in seven couples in Britain has difficulty conceiving, with thousands each year turning to In Vitro Fertilisation (IVF) to increase their chances.

But although infertility is often viewed as a female issue, 49 per cent of IVF cycles started in Britain are said to be due to ‘male factors’.

In the study, researchers used 261 healthy men aged 25 to 40 who had previously done little exercise.

One group took part in moderate intensity continuous training over 24 weeks. For the first 12 weeks they walked or jogged on a treadmill for 25 to 30 minutes per day, three or four times a week.

Over the following 12 weeks, they increased this to 40 to 45 minutes per session, for four to six sessions a week.

They compared this group to two others doing more intensive exercise, and to a group doing none at all.

The results of the study, published in the journal Reproduction, showed that men who exercised had improved sperm at the end of the training, regardless of how much they did. But those men who took part in the moderate group had the best results.

Compared to men who did no exercise, the volume of sperm rose by 8.3 per cent, cell motility increased by 12.4 per cent and cell shape improved by 17.1 per cent.

Sperm concentration rose by 14.1 per cent and there were 21.8 per cent more cells on average. The researchers, from Urmia University in Iran, found that the positive effects on sperm started to tail off within a week of stopping exercise.

The scientists concluded that exercise helped protect sperm against damage from oxidative stress, which is linked to activities such as smoking.

Lead author Behzad Hajizadeh Maleki said: “Our results show that doing exercise can be a simple, cheap and effective strategy for improving sperm quality in sedentary men.” However, he acknowledged that other factors may affect male infertility.

Professor Allan Pacey, an expert in male infertility at the University of Sheffield, said men could also take steps such as following a healthy diet, stopping smoking and wearing loose underwear.