Leg day at the gym? Sniffing CHOCOLATE before your workout could make it easier, study

Forget pre–workout shakes – all you might need to smash your next gym session is a whiff of chocolate.

Scientists have discovered that simply smelling dark chocolate before lifting weights can help people squeeze out significantly more repetitions without making the workout feel any harder.

In the study, volunteers who sniffed dark chocolate before tackling leg extensions completed around 18 extra repetitions than those who smelled nothing at all.

Researchers believe the aroma tricks the brain into feeling fuller, allowing people to focus more on exercise and less on hunger.

The effect was so pronounced that even milk chocolate provided a performance boost, although not as much as its darker counterpart.

Experts say the findings highlight the surprising power of smell to influence both body and mind.

Senior author Dr Mohamed Nashrudin bin Naharudin, from the University of Malaya in Kuala Lumpur, said: ‘Exposing moderately trained men to chocolate odours right before and between sets of resistance exercise significantly increased their overall training volume without increasing their perceived exertion.

‘Seeing a substantial increase in repetitions without the athletes feeling like they were exerting themselves any harder is a fascinating psychobiological outcome.’

These graphs show how the dark chocolate (90DC) group carried out more sets and repetitions compared to the milk chocolate (60MC) and control (CON) groups

Simply smelling dark chocolate before lifting weights can help people squeeze out significantly more repetitions, the researchers found (file image)

For their study, published in the journal Frontiers in Physiology, the researchers recruited 23 healthy men in their early to mid–20s and divided them into three groups.

Each group sniffed one of three odour samples – liquified dark chocolate containing 90 per cent cocoa, liquified milk chocolate containing 60 per cent cocoa, or a water sample that acted as a control for the study.

None of the gym–goers had eaten for the previous 10 hours.

For the research, they all performed leg extensions – which involves sitting down and extending the lower legs to lift a weight – in sets of 10 with 3.5 minute rest intervals.

‘Sniffing a 90 per cent dark chocolate odour added about 18 more repetitions to participants’ leg extensions,’ Dr Nashrudin bin Naharudin said.

‘A 60 per cent milk chocolate odour added about nine repetitions compared to the water control.’

Levels of hunger, fullness, desire to eat, and plans to eat in the near future were assessed before the study and 30 seconds after the odour sample had been sniffed.

Overall, sniffing dark chocolate consistently led to people reporting less hunger, reduced desire and intention to eat and greater fullness before exercise.

Sniffing dark chocolate (90DC) consistently led to people reporting less hunger compared to those who sniffed milk chocolate (60MC) or water (CON)

Why does smelling chocolate help?

Researchers think the aroma may:

Reduce feelings of hunger
Increase feelings of fullness
Trick the brain into expecting food
Help you complete more repetitions
Make exercise feel no more difficult despite doing more work

Across both types of chocolate, people also did not feel as though they were training harder but managed more exercise repetitions.

The researchers suggested the changes in appetite perception could be related to what people learn about smells from a young age.

Anticipating a food might have similar effects to when it is actually eaten, they suggested.

‘The dark chocolate scent serves as a learned cue for a rich, bitter and highly satiating food, which essentially tricks the system into an anticipatory state of fullness,’ Dr Nashrudin bin Naharudin added.

‘Conversely, the sweeter milk chocolate scent acts more like a hedonic reward cue, enhancing training volume by creating a highly pleasant sensory environment rather than by shifting basic metabolic hunger signals.’

Although it has not been tested yet, other appealing foods could also have an effect, the team believes.

‘We don’t think chocolate is entirely unique, though it is a food cue with incredibly strong, universally recognized reward associations,’ Dr Nashrudin bin Naharudin concluded.

‘Although this hasn’t been tested yet, other foods strongly linked to satiety could show similar effects. A person likely needs to find the odour familiar and appealing – or at least not repulsive – to trigger the psychological shift in appetite that’s needed to see a performance boost.’

Last month, scientists finally put an end to the ‘cupboard or fridge’ chocolate debate.

According to Professor Charles Spence, Professor of Experimental Psychology at the University of Oxford, chocolate tastes better from the fridge.

Chilling chocolate not only boosts its flavour but also its texture, according to the expert.

‘We like foods when they make some noise. One of the benefits of putting chocolate in the fridge is that you get a better snap when you break a fridge–cold bar,’ he explained.

IS CHOCOLATE GOOD FOR YOU?

Chocolate is undoubtedly the nation’s favourite dietary vice but lots of research over the years has found that it could actually be good for us.

With more than 300 chemicals in chocolate, scientists are investigating a whole range of health benefits linked to the food.

Researchers at Harvard University studied 8,000 men aged over 65 and found that those who ate modest amounts of chocolate lived almost a year longer than those who ate none.

Dr Neil Martin of the Cognition and Research Centre at Middlesex University exposed people to different smells and measured their brain activity.

The results showed that smell receptors in the nasal passages reacted so strongly to the chemical mix in chocolate that it left people on an emotional high.

A 100g bar of dark chocolate gives you 2.4mg of iron and 90mg of magnesium, around one third of the recommended daily amounts.

White chocolate, on the other hand, contains no cocoa solids, just cocoa butter, and is relatively high in fat. A 100g white Toblerone bar has a whopping 540 calories and 30.7g of fat.

Yet, despite its sugar content, chocolate is said by dentists to be less damaging to the teeth than many other sweets because it tends to be chewed quickly, not sucked.

There are also naturally-occurring tannins in chocolate that help to inhibit the growth of dental plaque.

And there is known to be a substance in all chocolate called phenylethamine (PEA), which is produced naturally by the brain and thought to increase levels of the mood-enhancing chemicals, serotonin and endorphins.

In theory, the more PEA you eat, the more amorous and aroused you feel, which is why chocolate has gained a reputation as an aphrodisiac.

A TV series on the Food Network called Food: Fact or Fiction? looks at how eating chocolate affects the brain.

Researchers found sharing chocolate with a loved one increased oxytocin levels.

This much-loved sweet treat also stimulates theobromine and phenylethylamine.

Phenylethylamine stimulates the release of B-endorphin which stokes the production of dopamine and norepinephrine.

These chemicals flood your system when you’re feeling loving.

Theobromine is chemically similar to caffeine and like its chemical cousin it stimulates the central nervous system and also has mood enhancing effects.