But before you book your fifth HIIT class of the week in the quest for eternal immunity, sweat with caution as there’s a fine line between a health top-up and overdoing it. “Too much exercise can actually be detrimental to our health,” Dr Joshua Berkowitz, medical director at IV BOOST UK says. “It may cause fatigue, so it’s important to be sensible.

For example, if you’re new to running, don’t try run a 10k off the bat – start gradually so it’s not a shock to your system.” A hot topic amongst medical professionals, it’s widely considered that extreme activities such as ultra-marathons or similar endurance events can actually reduce immunity (an opinion rubbished in a study by the University of Bath), yet for the mere gym-goers among us, it can have the opposite effect.

“Research has suggested that for a couple of hours immediately after exercise our bodies have fewer immune cells in our blood,” Dr Hemming say. “But, it’s now believed that these cells are just moving to other parts of the body to look for potential virus-causing bacteria, which is a good thing.

Moreover, studies have shown that there’s a link between moderate, regular exercise and a strong immune system. In fact, studies have shown that just 30 minutes of brisk walking increased the circulation of natural killer cells, white blood cells and other immune system strengtheners, enabling them to kill pathogens effectively. However, the immune-boosting effects of exercise are fairly short-lived so the key is to exercise regularly.”

Keep getting ill? Here’s how exercising really can support your immune system