Studies released today show that, despite good intentions, those who regularly exercise for two hours or more could be doing more harm to their bodies than good.

The research, which comes from Australian sports journal Alimentary Pharmacology and Therapeutics, shows that intense physiological stress on the body can trigger Leaky Gut Syndrome – a condition in which the gut lining weakens, resulting in the passage of germs and toxins into the bloodstream.

It’s believed that the resultant leakage of toxic waste is a primary cause of Multiple Sclerosis (MS) and Chronic Fatigue, and has a role to play in many other illnesses. With no immediate cure – though a gluten-free diet wouldn’t go amiss – those putting in the hours at the gym might be better off putting aside some time on the sofa.

But it’s not just your gut that could suffer from hard graft. There are a whole range of health risks associated with excessive exercise that the health and fitness industry would rather you didn’t know.

Whilst the gym claims to hold the key to a happier, healthier you, science seems to be saying that there really can be too much of a good thing.

Abnormal heart rhythms

A long but gentle session on the treadmill can’t hurt, right? Wrong. Those who regularly engage in endurance sports are at risk of causing permanent structural changes to heart muscles which scientists describe as ‘cardiotoxic’.