It's one of the most divisive issues among expectant mothers: is it really safe to exercise while pregnant? And how much is too much?
While most experts agree some light exercise is good for your baby, stars like Binky Felstead and Kim Kardashian have found themselves in the firing line after sharing details of their pre-natal workouts online.
But personal trainer Monty Simmons told The Daily Mail that the rules are easy enough to follow, and advises mums-to-be to stick to 30mins at a time and avoid anything too strenuous - and hobbies like judo, hockey, road cycling and skiing are out.
"Despite some claims that rest and relaxation is the only course of action for a safe pregnancy, evidence shows that active women are less likely to experience problems in later pregnancy and labour - and will find it easier to get back into shape after the birth"' says Monty.
"If you're not used to regular exercise, but you want to stay in shape and stay healthy, increase your exercise very gradually."
"If you're already active, keep at it but of course tone down the intensity as you get closer to your due date, and swap out any risky or extra-energetic routines for something safer and slower."
Do work out for 30 minutes a day
"You should aim for around 30 minutes of exercise each day where you can, even if it's just 30 minutes of walking," says Monty. "But it's so important that you don't exhaust yourself."
"As a rule, you should be able to hold a conversation as you exercise while pregnant, so if you can't do that, you're probably being too strenuous."
Don't do judo, hockey or cycling after 16 weeks
There are plenty of options to keep you feeling healthy and active for as long as possible, but Monty advises that women should choose their sports very carefully: "Minimise the potential for foetal damage by reducing the impact of the sport or exercise you're doing," he advises.
"I'd always recommend avoiding contact sports like judo or hockey, especially after the 16-week mark, and avoid sports where you might be more likely to take a tumble, such as road cycling, skiing or horse-riding.
'Also, you should avoid any exercises where you need to lie flat on your back for prolonged periods, as the weight of the baby bump will press on the main blood vessel transporting blood back to your heart - which can make you feel faint."
Do keep up your core stability
"One well-known effect of pregnancy is a weakening of the abdominal wall, particularly your transverse abdominus," says Monty. "This will likely cause rectus diastasis - this is a separation of the abs - which weakens core stability and contributes to lower back pain. "
"Hip strengthening exercises, leg exercises and back exercises will help to support your structure and reduce the stress on your upper back."
"If it's your lower back that's inflamed, try some exercises that will reduce the compressive load on your spine; swimming or aqua-natal water aerobics provides great relief and reduces the pressure on your body, but make sure your instructor is properly qualified and is fully aware of your pregnancy."
Don't do burpees
"After the 16-week mark, you should avoid exercises that involve rapid level changes such as burpees," says Monty.
Do make sure you're eating enough
"Maintaining your fluid levels is paramount, to avoid blood thickening and overheating," says Monty. "Keep well hydrated throughout your workouts and afterwards too, by drinking lots of water and other fluids."
As well as keeping hydrated, Monty recommends taking nutrition especially seriously during pregnancy, explaining: "Ensure you are giving yourself plenty of nutrients to replenish and feed your body."
"During pregnancy, you'll need to consume around 350-450 more calories each day than before you were pregnant, and this number only needs to increase if you're exercising too."