Putting exercise to rest

So, if it's just a case of a runny nose and a stuffy head, it might be alright to do gentle exercise. But, even if you do get the all-clear on the neck check, Williams says taking a break might be better in the long run.

'I would suggest that if you have got a cold or the flu, it is probably best to rest, keep warm and hydrated, take Vitamin C and just try to get rid of it as soon as possible. Then you can get back to training,' he says.

If you ignore more serious symptoms, such as swollen glands, vomiting, chills, a fever or an aching or very tired body, you could do your health serious damage, says GP and medical columnist Naomi Craft.

'It's not safe to exercise with a fever because of the risk of sudden death from abnormal cardiac rhythm. This is very rare, but can happen if a virus that causes symptoms affects the heart muscle,' explains Craft. 'I recommend no exercise with a fever, and waiting 24 hours after a fever has settled before starting again.'

Reluctantly, me and my fever stayed well away from the gym for three entire weeks. By the time I went back, I felt like a novice. I was exhausted after only 10 minutes on the cross trainer, a machine I've been known to spend an entire hour on.

Fitness expert Joanna Hall says getting back to exercise after an illness can be tough, but it's worth persevering.

'It gnaws away at your confidence and you can feel frustrated and irritated, but if it has only been a few weeks, you don't actually lose as much of your fitness as you think,' she says.

While it can be tempting to go extra hard to make up for lost time, Hall advises a gentler approach.

'If you've had time off, it's a good idea to ease into things. Start out at a lower intensity and work out for a shorter length of time. Try things that focus on your posture, like Pilates, which can boost your confidence if you've been lying in bed a lot.'

Though you might feel like you're right back where you started when it comes to working out, you'll regain your strength and fitness much faster than someone starting to exercise for the first time as your muscle memory will be better developed.

If your gym offers personal sessions to reassess your workout, sign up for one when you go back. Learning some new moves will give you something to focus on and draw your attention away from your break.