When your masculinity is compromised – and we’re talking on a hormonal level, not screaming at a spider in the tub or a botched attempt at a fairground hammer game – finding the culprit often means going balls deep. Aside from the libido-enhancer we commonly know it as, testosterone dictates everything from your mental health to the snugness of your shirt sleeves. While it’s a sad fact of life that hitting the age of 30 marks the beginning of a steady decline in T-levels, omitting certain things from your lifestyle can help maintain the fire in your loins and the bulge in your biceps a little longer.

Alcohol

A bit of Dutch courage is enough to give some blokes the kind of primitive manliness to take on grizzly bears (or go on a first date). But when bottoms are up, testosterone must come down. According to the Indian Journal of Physiology and Pharmacology, alcohol consumption not only negatively impacts testosterone production, but it can also cause oxidative damage to testosterone molecules already in circulation.

Chewing Gum

Bad breath may be a turn-off, but the solution could be turning you off. An animal study published in The Journal of Food and Chemical Toxicology found that spearmint and other varieties of menthol often found in chewing gum can suppress testosterone. A sticky situation, indeed.

Full Fat Coke

Measuring the correlation between sugar intake and testosterone, an Oxford University study found a 25 per cent drop in the levels of men who consumed 75 grams of the sweet stuff a day. Sure, reaching for the red can might help see you through a slow afternoon in the office, but it’s also adding a hefty 39g of refined sugar to your daily total, so you’re probably best off with a bottle of water.

Lack Of Sleep

It’s time to wake up to some testosterone truths. Insufficient shut-eye causes the body to produce more of the stress hormone cortisol, which in turn blocks the production of testosterone. According to a University of Chicago study, men averaging five hours a night saw a 15 per cent decrease in T-levels compared with those who logged the recommended eight.

Drinking From Plastic Bottles

“Hippy nonsense!” we hear you cry. Well, not according to The Journal of Clinical Endocrinology & Metabolism, which linked phthalates – a family of chemicals used to make disposable bottles – with a dip in the male hormone. With this plastic plague reportedly seeping into everything it comes into contact with, it may be time to hop on the reusable glass bandwagon.

Soy Milk

The grass isn’t always greener for those who dodge dairy. Several (albeit heavily contested) studies have associated the legume with the production of an antiandrogen (aka testosterone-blocking) chemical in the gut called equol. So if full fat’s not your poison; oat, nut or hemp are all worthy stand-ins.

Long-Distance Running

According to a study from the University of British Columbia, Mo Farah-wannabes pounding over 40 miles of pavement per week had noticeably lower levels of testosterone than those who run short-distance. Scientists put this down to endurance athlete’s chronically elevated cortisol levels. So if taking on a marathon, make sure you’re also getting adequate duvet time, alongside other cortisol-reducing measures.

Croissants

Delicious though they may be, mainlining your continental breakfast pastries of choice means saying au revoir to your va va voom. Many of the shop-bought varieties use types of margarine or spread containing trans fats, which according to The British Journal of Nutrition are a sure-fire way to see your testosterone levels plummet. Quelle horreur.

Bad Body Language

In social psychologist Amy Cuddy’s Ted Talk, she discusses how physiological changes come about from the power you give off in your body language. Testing her theory, she asked men and women to hold high or low-power poses (making themselves small or touching their necks) for two minutes, then measured the changes in their testosterone levels. Those in the low-power stance experienced roughly a 10 per cent decrease. An excuse to keep manspreading, then.

Anabolic Steroids

This one’s a bit confusing, given their popularity among bodybuilders seeking quick hits of testosterone. But the effects of anabolic steroids are short-lived. According to the journal PLOS One, loading your muscles with artificial strands of the hormone tricks the body into thinking it has produced enough naturally. Inject too much, and the slowdown can become permanent.