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Caffeine and training: the lowdown

Want the lowdown on how caffeine can enhance your training? Nutritionist Sophie Lester shares all.

Some athletes swear by it, and others can’t dispute it - a dose of caffeine is beneficial for your workout. Delicious coffee AND improved workout performance? Surely, it’s too good to be true?

What is caffeine?

Caffeine is a stimulant that exerts its energising effects on the nervous system. It is found naturally in certain foods (such as coffee and cocoa) but manufacturers also add it artificially to some foods, beverages and sports supplements.

What are the benefits of caffeine on exercise?

Unlike many of the other supplements out there, science backs the beneficial effects ofcaffeine on sports performance. So your morning cuppa has a place on the prestigious and permitted list of performance enhancing supplements.

Supplementing with caffeine before exercise improves endurance capacity (you can go harder for longer) but also increases feelings of physical strength – this means you may push yourself harder and gain more from your workout. Experts have found that caffeine can even reduce feelings of exertion - in other words, you feel tired less quickly [2].

The benefits don’t end here. Experts also propose that caffeine may protect your glycogen stores in the body (your glucose storage). This means you have more energy stored for future bouts of strength and power - and could even enhance fat metabolism for better aerobic capacity! [3] We bet you never look at your coffee the same way again.

How much caffeine should I have?

The ideal dose of caffeine is around 3mg/kg of body weight – this is about 240 mg for an 80 kg man.The amount that is right for you depends on your body weight; lighter people will need less caffeine to feel benefits. This amount of caffeine is equivalent to the caffeine in 2-4 cups of coffee.

One important point is knowing when to supplement. Experts recommend that the ideal time is thought to be around 30 minutes to 60 minutes before exercise. This gives your body enough time to absorb the caffeine. The stimulating effects should be at their peak (the greatest beneficial effect) by this time.

Where can I find caffeine?

Coffee (we know this one) – 100 mg per 100 ml (but this depends on the method of preparation such as fresh vs instant and also on the variety of coffee) Black tea – 5-20 mg per 100 g Chocolate – 5 mg per 100 g Energy drinks – 200 mg per 100 g

*Women who are pregnant should limit their intake of caffeinated drinks to 200mg/day because it can lead to babies having low birth weight and increase the risk of miscarriage [1].

What are the drawbacks of caffeine on exercise?

One drawback is that the effect of caffeine on individual performance is very variable. One study found a beneficial effect of caffeine in 14 elite male swimmers. But, when viewing the individual swimmers' performance, two swimmers experienced an adverse outcome [4].The best way to find out how caffeine affects your individual performance is to simply try it - supplement before your workout or training and track changes in your speed, strength or feelings of energy. Repeat the test a few times to get a more accurate insight into your personal response.

Be aware that even a small amount of caffeine can cause undesirable effects in susceptible people. For example, some people get migraines from caffeine, and some people experience stomach cramping after consuming it. Too much caffeine in anybody can cause headaches and insomnia – an optimal amount of sleep is essential to recoup and repair your muscles to improves muscle strength. So, ensure your caffeine intake doesn’t interfere with your sleep quality – a good rule of thumb is to avoid caffeine in the afternoons and evenings.

Also, caffeine is a diuretic (it promotes water loss from the body through urine). Experiencing dehydration of only 1% can damage your performance, and lead to headaches and tiredness, so ensure you drink plenty of fluids too!

References [1] https://www.nhs.uk/live-well/eat-well/water-drinks-nutrition/ [2] Spineli, H., Pinto, M.P., Dos Santos, B.P., Lima‐Silva, A.E., Bertuzzi, R., Gitaí, D.L. and de Araujo, G.G., 2020. Caffeine improves various aspects of athletic performance in adolescents independent of their 163 C> A CYP1A2 genotypes. Scandinavian Journal of Medicine & Science in Sports, 30(10), pp.1869-1877. [3] Gui, Y., Shi, X., Huang, C., Yi, S. and Lin, D., 2018. PO-304 Caffeine Supplementation Altered Metabolic Profiles in High-intensity Interval Training. Exercise Biochemistry Review, 1(5). [4] Lara, B., Ruiz-Vicente, D., Areces, F., Abián-Vicén, J., Salinero, J.J., Gonzalez-Millán, C., Gallo-Salazar, C. and Del Coso, J., 2015. Acute consumption of a caffeinated energy drink enhances aspects of performance in sprint swimmers. British Journal of Nutrition, 114(6), pp.908-914.