Busting your butt in the gym and breaking down muscle fibers under a ton of iron isn’t easy, but it’s the only way you’re going to get the big and beyond-ripped physique that makes you the envy of everyone you know. But there’s a fine line between doing too little and doing too much. And, unless you can do just enough work to grow – unless you can get it right – all your hard work will be for nothing, and you’ll end up getting sick. And how, exactly, does doing too much exercise make you sick?

A study looked at the underlying mechanisms of exercise and found that too much exercise makes you sick by altering your physiology and that doing too much exercise changes the mitochondrial transmembrane potential (TMP) of leukocytes – key immune system cells – and increased cell death rates, while simultaneously increasing inflammation and triggering muscle breakdown.

FUSION FACT

To build muscle, you’ve got to get it right, and this means working with all-out muscle building intensity until you’re finished – and not working a minute later. By working with precision, you’ll get all of the upside with none of the downside – like massive cell death and skyrocketing inflammation.