Ask the expert: Is it all right to continue running while pregnant?
Q: I run regularly and have just found out that I'm pregnant. Is it OK to keep running, and when should I stop?
A: Professor Andrew Shennan, clinical director at the pregnancy and baby charity Tommy's Preterm Surveillance Clinic, says: "It's perfectly reasonable to continue running while pregnant, if you wish; indeed we would recommend continuing accustomed exercise.
"We now know running has no detrimental effect on the size of the baby or when labour occurs. Nearly 1,300 regular runners around the world from the parkrun community were investigated in the biggest study of running in pregnancy to date, and it found that frequent and intense running was also safe.
"It's important to be fit for birth, and exercise in pregnancy is known to be beneficial, including reducing backache, swelling and improving circulation (and veins), as well as being associated with better mental health and feelings of wellbeing.
"However, listen to your body, and don't overdo it, as your body will not be the same and it isn't a time to start doing new strenuous exercise. As long as you feel comfortable and your joints are fine, it's safe to continue running until the end of pregnancy or birth.
"Even intense or frequent exercise is OK to continue, as long as you're used to it – although long distance running (for hours) in early pregnancy should be avoided as the body temperature goes up and this may affect the baby's early development (first 12 weeks).
"Some women are concerned about their pelvic floor, but exercise, including running will reduce problems related to the pelvic floor (eg prolapse). National recommendations suggest 20 minutes of exercise a day in pregnancy but avoid contact sports or scuba diving.
"It's all right to do more if you're used to it, but if you start exercise for the first time in pregnancy, build up gradually."