The health & fitness media is always quick to hit us over the head with the latest ‘superfood’ fad, be it Pomegranate, Acai Berries, Wheatgrass, or whatever the current flavour of the month fruit/veg is being declared the indisputable last word in nutritional goodness.
The simple truth, however, is that pretty much all varieties of fruit and veg contain nutrients important to our health, and it’s rather difficult to single out anyone as unequivocally ‘better’ than any other due to the huge range of vitamins and minerals found in natural produce (check out an interesting article that discusses many of the other issues with a lot of these ‘superfood’ media articles here).
The best advice is to try and include as wide a variety of fruits and veg into your diet as possible and to ensure they come from a whole range of different shades and colours (a plant’s tint is determined in part by the most abundant nutrients contained within).
Very occasionally, however, a particular compound or substance found within a fruit or vegetable is discovered to have previously unrealised benefits that can help set it apart in terms of its potential usefulness to the athlete/regular exerciser.
On-going research has most recently shown such promising results in beetroot juice – benefits that will be of great interest to the squash player looking to gain a physical edge in their performance.
Already known as a great source of antioxidants, the very high nitrate content of beetroot has been more recently demonstrated to improve physiological performance by mediating an array of biological responses – potentially resulting in a significantly increased volume and intensity of work output during a training session/sporting event of anything up to 20%, and possibly also expediting your subsequent recovery – of particular interest to squash players is that these benefits are theorised to be most apparent in high-intensity exercise, of around 30 minutes in duration.
The majority of studies on nitrate have used beetroot juice, but beetroot isn’t actually the only food that contains a high content – other good sources include spinach, rocket and lettuce. Beetroot juice is the substance most commonly used for concentrated nitrate intake however, because it is far easier to extract, measure, and consume.
There are many supposed nitric oxide stimulating sport supplement products also on the market, usually with the active ingredient of the amino acid L-arginine. Supplementation in this form has not been shown to significantly increase blood nitrate levels nor nitric oxide production in the way the ingestion of nitrate-rich foods such as Beetroot has been demonstrated to do so, however.
The article ‘Nitrate Ingestion: Implications for Performance and Training‘ in the NSCA Strength & Conditioning Journal is a great piece that goes into a lot more depth about the science behind it all, but in short the mechanism of effect of the nitrate boost is theorised to come primarily from blood vessel dilation and an increased blood supply to the working muscles.
When you consume beetroot juice the bacteria in your saliva transforms nitrate into nitrite, which is then delivered to your digestive system for absorption after you swallow. Plasma nitrite flows through the bloodstream and is then transformed to nitric oxide by the body tissues (not to be confused with nitrous oxide – ‘laughing gas’).
This nitric oxide increases blood flow and supplies your muscle tissues with additional oxygen and at a faster rate, meaning your tissues can continue to use the oxygen-dependent energy systems to produce energy for longer and at a higher intensity.
The nitric oxide is also believed to have positive effects on muscle cells, by improving their ability to contract and produce more energy.
In addition, recent research has even suggested that similar interactions within the brain can help increase mental performance and enhance reactions during prolonged intermittent exercise, alongside boosting repeat sprint performance – both aspects crucial to the squash player.
For best results, researchers have recommended drinking approximately 500ml Beetroot juice per day (commercially available concentrated ‘shots’ may also contain equivalent nitrate levels – you’d need to eat at least 5 whole Beetroot to get the equivalent amount, however).
Taking this amount of juice onboard around two and a half hours before training/competition will potentially result in immediately apparent beneficial effects for some individuals, but researchers suggest it better to add Beetroot juice to your diet on an on-going basis to help maximise and sustain further performance enhancements – this will also help make the most of the additional proposed health benefits of Beetroot juice consumption including lowered blood pressure, improved general blood flow, and reduced risk of heart disease.
No negative side-effects have been shown or theorised on consumption of this amount of Beetroot juice (though long-term studies are still on-going), though the flavour is somewhat of an acquired taste… It does also have the rather bizarre by-product of turning your urine an interesting shade of pink!
Pretty pink pee and mildly offended taste buds though, are surely a small price to pay for those looking for such a potentially potent physical boost.
B.Sc.(Hons), CSCS, NSCA-CPT, Dip. FTST
SquashSkills Fitness & Performance Director
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