Moderate exercise improves sperm quality and quantity

Moderate exercise improves sperm quality and quantity, according to new research.

Previous research showed that some types of exercise, such as long distance running, can have a negative effect on sperm, but this study suggests that moderate exercise three times a week improves sperm quality.

'Our results show that doing exercise can be a simple, cheap and effective strategy for improving sperm quality in sedentary men,' said Behzad Hajizadeh Maleki, a researcher at Urmia University, Iran, and lead author of the study, which was published in the journal Reproduction.

The researchers recruited 261 men who previously did little exercise, and divided them into four exercise regimes of differing intensity: moderate continuous intensity, high continuous intensity, high-intensity interval training exercise, and a control group that did no exercise.

Moderate continuous intensity and high continuous intensity exercises involved running on a treadmill for either 30 minutes or one hour for three or four days per week, respectively. High-intensity interval exercise involved one-minute bursts of sprinting, followed by a one-minute recovery period and then repeating this 10–15 times.

The men performed the exercise regimes for a course of 24 weeks. The researchers took semen samples before and after the regimes and analysed them for markers associated with fertility, including sperm count, size and motility, as well as for markers of inflammation and oxidative stress.

All groups doing exercise showed universal improvement in sperm quantity and quality. Those following a moderate intensity training program showed the most improvement – a 8.3 percent increase in sperm volume, a 12.4 percent increase in motility, and 17.1 percent improvement in cell shape.

Following a week of no exercise, nearly all improvements dropped back to pre-training levels for the groups. Only the moderate intensity group continued to show improved semen volume and motility for up to 30 days after the training program.

All men in the three exercise groups also reduced their body mass index. While the authors noted that this will have contributed to improved sperm quality in their study, they believe moderate intensity exercise may have been the most effective as it reduced the exposure of sperm to oxidative stress and inflammation.

Maleki added: 'It's important to acknowledge that the reason some men can't have children isn't just based on their sperm count. Male infertility problems can be complex and changing lifestyles might not solve these cases easily.'

One in three couples struggle to conceive as a result of semen quality. The researchers intend next to investigate if improvements in sperm quality caused by exercise also affect its fertilising potential.