The star - who has refused to reveal exactly when her new baby is due - is already mummy to three-year-old Honor Marie.
Defending her five-day-a-week regime, Jessica says she is not taking it to the extremes that she did with her first pregnancy, when her exercise programme included walking on a treadmill at an incline, followed by stretching, additional cardio, and some light weights.
'I'd like to still do something five days a week, from a half hour to an hour - nothing excessive, just some moving. It makes the whole pregnancy so much easier. The more fit you are, the easier the birth is, and a healthier baby you're going to have,' she says.
Jessica has also revealed she is trying to relax more and not give in to all the anxieties she had with her first pregnancy, which she said was 'new and kind of terrifying':
'Now I know what to expect, she says, adding 'It's like 'it's fine, I've been there before' - with Honor, I was constantly like, 'is she moving? Is her heart beating?' I'd worry about everything and with this baby, I don't have the same anxieties.'
Do you think exercising five days a week is excessive during pregnancy?
Or is it important to keep your fitness levels up?
Are you pregnant and working out?
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