Nell McAndrew has exclusively revealed her second pregnancy to HELLO! magazine.
The model is 20 weeks pregnant and is keeping up her fitness regime by running six miles a day along with twice-weekly gym sessions.
"A lot of people say to me 'Should you be doing that?' she tells HELLO!. "They're concerned, but there's no need because my body is used to doing a lot of exercise.
To me it doesn't feel very much because I used to run 90 miles a week – twice what I do now."
Nell, 39, who already has a son Devon, six, with her property developer husband Paul Hardcastle, still fits in to her size 8 sports clothes, albeit with the waistband folded down.
Even when she was nine months pregnant with Devon, she still didn't need maternity wear, and wore size 10 sportswear instead.
While thier new arrival is due in March, her first pregnancy ended in heartache. In 2005, she told BBC sports presenter Sue Barker that she was pregnant live on TV minutes before taking part in the Great North Run.
Days later, Nell discovered that her baby had amniotic band disorder, where tissue that should be protecting the foetus instead forms around it, disrupting growth.
"I told everyone a week before the three-month mark and I shouldn't have said anything,' she reflects. "But I was just so happy that I couldn't keep the news to myself."
Nell breastfed Devon until just after his third birthday and in spite of some of the criticism she received, she wouldn't be deterred from doing the same again.
"If I do extended breastfeeding again, I certainly won't worry about what people think of it".
To read the full exclusive pick up the latest copy of HELLO!, out now.