Khloe Kardashian has hit out at haters who slammed her for exercising while pregnant.

Khloe, who is around 6 months pregnant, received criticism from fans for working out - and the reality star soon hit back.

She wrote on Twitter: "For the ones who think they are physicians all of a sudden... MY doctor and I communicate and my workouts are cleared and highly recommended. Thanks kiddos!”

But whether or not you have the budget for personal trainers like Khloe, who documents her workouts on Keeping Up With The Kardashians, or 5-star gyms, keeping well is a priority everybody should honour.

But exercising during pregnancy is a subject that throws up a lot of confusion, across the board.

Is it safe?

"There certainly is a good deal of confusion surrounding what's safe and what's not safe exercise-wise in pregnancy. There's a tendency for everyone to voice their views, especially when celebrities share their workouts on social media - suddenly the whole world has an opinion. It's almost as if when people fall pregnant, they become public property, others consider it their right to advise and even criticise," says pregnancy and postnatal fitness expert Dr Joanna Helcke, the brains behind the award-winning FitBumpBox and FitBumpBall exercise and wellness packages for mums-to-be .

"Although this is usually well intentioned, the net effect is many women feel unsure as to what exercise can be done and what should be avoided."

"We know there can be confusion about being active during pregnancy, and sadly, some examples of women being criticised for remaining active whilst pregnant. We want to show the normalness of being active during pregnancy," explains Kate Dale, Sport England's head of brand and digital strategy.

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What women want?

Pip Black and Joan Murphy, co-founders of 'fitness destination' Frame, have just launched a new online platform for their 'Mumhood' classes, which feature yoga, Pilates and barre classes for different pre and post-natal stages.

"Mumhood was born out of the fact that when Joan, and then I, became pregnant for the first time, even working in the industry, we found it really hard and at times very confusing to find information about exercising during pregnancy that didn't contradict itself, or err on the side of caution.

As people who were used to being active and needed to be to keep us sane, we started to do a lot of research ourselves into the risks and what type of exercises were safe, and which also would benefit you in terms of preventing pregnancy-related aches and pains, helping with the birth and with post-natal recovery."

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It’s personal

Pregnancy - as with most things - does not affect every woman in the same way. Sometimes there are also long-term health concerns that might flare-up or affect somebody's needs or limits in terms of physical activity during pregnancy.

The Royal College of Midwives' official advice is clear: it is important to keep physically active during pregnancy - and this is the over-arching message.

But that doesn't mean heaping a ton of pressure on pregnant women to make sure they meet some pre-determined fitness target, and neither should those who are able to be pretty active get criticised.

The guidelines also note that everybody consults with a healthcare professional for individualised advice, and also that their activity and fitness levels before pregnancy be taken into account.

"Every woman brings to pregnancy her own individual fitness levels, so what might be right for one person could well be entirely inappropriate for another. We don't all think we should be emulating the Rebecca Adlingtons or Jessica Ennis-Hills of this world - they're top performing athletes - so why should we feel compelled to exercise like the latest celebrity who shares a video of her workout?

“Her workout will, in all likelihood, have been tailored specifically for her body, fitness and the way her pregnancy's progressing," says Dr Helcke. "The key is to ensure you're not throwing new stuff at your body, and that you're working at a level that is moderate by 'your' standards."

The Royal College of Midwives' advice for women who weren't regularly active before pregnancy is to chat with their GP or midwife, and then ideally aim to begin exercising for 15-minute bouts or less, three times a week, increasing gradually to daily 30-minute sessions.

"Whilst 'listening to your body' may sound rather corny or a little unscientific, it is absolutely essential when it comes to keeping exercise safe during pregnancy," says Dr Helcke.

"Women should be on the lookout for telltale signs such as feeling more fatigued than usual and taking longer to recover from a workout. Never attempt to work through these signs - they're our body's way of telling us to ease off. If this means working out less intensively, for a shorter period, or even moving to a more gentle form of fitness, then so be it."