Ova-training: exercise can have an effect on fertility
Q My wife and I have been trying to start a family for two-and-a-half years and are now going through the usual investigations for infertility. Are long durations of exercise detrimental to conception? Would shorter, faster bursts of exercise be a better option? Will my training (about 30-40 miles a week) affect my fertility and if so, is there anything I can do about it?
A Put in its simplest form, pregnancy will occur when a sperm meets a ripe egg in a suitable environment. If any of these criteria are not met, the chances of reproducing are reduced, if not prevented. The role of the fertility expert is to ensure the sperm is mature, properly formed, able to move and properly produced.
Some couples are infertile, for whatever reasons, and, in most cases, tests will show this. Far more are said to be sub-fertile, commonly as a result of a low sperm count or some failure in ovulation. In these cases fertility can be boosted if the partners have what is generally described as a “healthy” lifestyle. Alcohol, smoking, stress, drugs, lack of sleep and exercise, obesity, a poor diet and illness are just a few of the factors that may reduce the chances of conceiving. Conversely, it is possible to go to the other extreme and overdo some of these. If you are too thin or have too much sleep you may also reduce your chances of having a baby.
What about exercise and the male athlete? The textbooks of sports medicine do not even give it a mention. It is well recorded that biochemical changes occur in the high-mileage runner, and among those affected is testosterone production, the first brick in the male reproductive cycle.
Research suggests that an athlete covering more than 70 miles a week may be affected. If he starts from a very fertile beginning, a small reduction in testosterone is unlikely to make much difference to his procreative capabilities, so there is no suggestion that high-mileage athletes need to reduce mileage in order that their partners may conceive, but it is yet another factor which needs to be considered in the infertile.
In your case, 30-40 miles a week is probably the optimum distance, but run yourself to exhaustion too often, and your body could object by reducing testosterone production. It is probable that testosterone levels have been estimated as part of your tests, but if not, they ought to be.
—Dr Patrick Milroy, RW Medical Advisor