Why chocolate is the perfect pre-workout snack for midlifers
Good news for those with a sweet tooth – a new study shows that chocolate could be the ideal pre-exercise snack. Researchers have found that a compound in cocoa increases blood flow and makes exercising easier due to a faster uptake of oxygen. The benefits are most pronounced for midlife gym-goers, as the rate of oxygen consumption at the start of exercise slows down as we age.
The team of scientists from Liverpool Hope University and Liverpool John Moores University tested the effects of cocoa flavanols – which are found in cocoa powder and chocolate – on a group of “sedentary” but healthy adults aged between 40 and 60. Through their research, published in the European Journal of Applied Physiology, they found they had a positive effect on exercise performance.
But, before you reach for the Dairy Milk, it comes with a caveat – natural cocoa powder or (at a push) dark chocolate are the best ways to boost your flavanol intake and reap the workout-boosting benefits. Cocoa flavanols can also be taken as a supplement.
Natural cocoa powder contains 34.6mg of flavanols per gram, 70 per cent dark chocolate contains around 1.156mg per gram, but milk chocolate has just 0.73mg per gram. So, tempting as a bar of chocolate may be, the researchers suggest opting for a pre-workout smoothie that contains a tablespoon and a half of cocoa powder to improve exercise performance.
"It is preferred to take supplements over eating dark chocolate since potential beneficial effects of cocoa-flavanols occur during exercise when greater than 400 mg flavanols are consumed," says Daniel Sadler, lead author on the study. "To achieve this dose from dark chocolate alone may well negate the beneficial potential of any bioactive constituents because of its fat and sugar contents."
The flavanols found in cocoa are part of a family of bioactive compounds called “flavonoids” that have anti-inflammatory and antioxidant properties. There are several different types of dietary flavonoids, which can be found in fruit and vegetables such as berries, kale and tomatoes, but also in plant products like tea, coffee, red wine and dark chocolate.
In the study, participants were put through their paces on a lab-based exercise bike over the course of five weeks to establish their power output and peak VO2, which is the maximum amount of oxygen the body can use during exercise.
Following that, they were either given a 400mg cocoa flavanol supplement or a placebo for seven days. They then underwent exercise tests to measure the time it took their oxygen delivery to respond to exercise. The shorter the response, the better their performance and the better their bodies were able to cope with the given exercise.
Those who were given flavanol supplements reduced this time from around 40 seconds to 34 seconds – a six second reduction that the researchers say is significant as it “exceeds the minimum physiologically relevant change” of five seconds. The research could have “clinical potential in contributing to improved tolerance of daily life activity in middle-aged adults”.
"Engaging in exercise becomes more challenging as we age, especially if we have poor fitness levels," says Sadler. "Without regular physical activity, ageing slows the rate at which our muscles consume oxygen during the onset of exercise. This is due to impairments in blood flow supply to the active muscles. As a result, our ability to tolerate exercise is weakened.
"The finding that cocoa flavanol supplementation increased the rate of oxygen consumption at the onset of exercise is very encouraging for this demographic. It suggests that a simple nutritional supplement can improve exercise tolerance, and therefore enhance the likelihood of sustaining an exercise regime."
“The research findings are particularly interesting but the study was conducted on a small number of participants. As a result, more research into the role of cocoa flavanols on performance is required,” says nutritionist Jenna Hope. “However, incorporating flavanols into the diet is beneficial for supporting general wellbeing and additional sources include berries, green tea and kale, to name just a few.”
This comes after a 2016 study from Kingston University found that a daily snack of dark chocolate boosted athletic performance in a group of nine amateur cyclists.
Flavonoids have also been linked to other health benefits: for instance, a US study found that cocoa flavanols increase memory in people aged 50-75, which suggests they could have a role to play in preventing cognitive decline in old age. As they have anti-inflammatory properties, research has also shown that flavonoids can lower the risk of cardiovascular disease and type 2 diabetes. Cocoa is also rich in magnesium, which plays a critical role in protein production, energy creation and cognitive function.
The best cocoa and dark chocolate to try
Naturya Organic Fair Trade Cacao Powder
A natural cocoa (or cacao) powder is the best way to get the performance-boosting benefits of flavanols other than supplements, as it contains an average of 34.6mg of flavanols per gram. Cacao and cocoa powder are very similar – the only difference being the latter has been roasted and processed at a higher temperature. This Fairtrade, organic cacao powder is also rich in iron, potassium and magnesium.
Green & Black's Dark Chocolate 70% Cocoa
Dark chocolate contains far fewer flavanols than cocoa powder itself, but a 70 per cent-plus dark chocolate still contains around 1.156mg of flavanols per gram and offers other health benefits, too.
Montezuma's Absolute Black 100% Cacao
Fitting easily into a pocket or, indeed, a gym bag, this is the ultimate dark chocolate bar - for those who can handle it. 100 per cent cocoa, with no added sugar or milk, its tastiness has most certainly not been compromised.
Pana Raw Chocolate 80% Cacao
If you want to feel really smug about a chocolatey snack, opt for “raw” chocolate. This bar is made from just two ingredients: minimum of 80 per cent unprocessed cacao and then dark agave nectar.
Pre-workout cocoa smoothie recipe
By Jenna Hope, Registered Nutritionist
You will need:
- 1 ripe banana
- 300ml milk or almond milk
- 1 tbsp oats
- 1.5 tbsp cocoa powder
- 2 tsp peanut butter
- 1 tsp honey (optional)
Method:
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