From Football League Clubs to world-class sports stars like Venus Williams, Tom Daley, David Haye, and Lewis Hamilton, it’s no coincidence that more and more sportspeople are giving up meat and adopting a vegetarian or vegan diet. Anecdotally, many claim that plant-based eating helps their recovery, gives them more energy, and reduces their injury rate. While there is currently no hard scientific evidence to back these claims, most studies have found that eating a vegetarian diet certainly does not put athletes at a disadvantage when it comes to fitness training. But why are more and more athletes noticing performance benefits after switching to a plant-based diet?
It could be that eating a diet rich in fruit, vegetables, whole grains, beans, lentils, nuts, and seeds is aiding performance and recovery via its positive effects on the gut microbiota – the population of trillions of microbes that inhabit the gut. In other words, it’s not necessarily the absence of meat that’s helping athletes perform or recover better, rather their higher intake of plant nutrients and lower content of ultra-processed foods that tend to provoke inflammation. We are talking about fibre, polyphenols, and antioxidants – plant chemicals that may help reduce oxidative stress associated with prolonged exercise and modulate immune function and inflammation.
Consuming more fibre – and, importantly, more diverse types of fibre – as well as polyphenols means that you’re feeding the billions of microbes (bacteria, viruses, and fungi) in your gut. These microbes break down the fibre we cannot digest ourselves and produce, among other things, short-chain fatty acids (acetate, propionate, and butyrate) that provide fuel for our intestinal, liver, and muscle cells, and have numerous other health benefits. These include increased immunity, less oxidative stress, and lower inflammation, all key factors necessary for muscle recovery after exercise. Additionally, butyrate helps regulate energy metabolism, appetite hormones, and body composition.
There’s evidence that our gut microbes affect our exercise performance. A comprehensive review of 33 studies concluded that our gut microbiome plays a key role in controlling oxidative stress and inflammatory responses as well as improving metabolism and energy expenditure during endurance exercise. In one 2014 study, athletes who took a probiotic supplement for four weeks were able to exercise longer before reaching fatigue than those who took a placebo.
In other words, the healthy gut microbiota is critical for optimal performance and recovery as well as health. It is also associated with a more favourable body composition, which roughly translates into faster times and better athletic performance.
The best way to increase the diversity of your ‘healthy’ gut microbes is to eat a wide range of foods rich in fibre, polyphenols, and probiotics. These provide ‘food’ for them, enabling these microbes to multiply. There are many types of fibre and the more types you eat, the greater the benefit.
Plant-based foods Try to get as many different kinds of fruit, vegetables, whole grains, pulses, nuts, and seeds in your diet as possible. Variety is key because each contains different nutrients that the gut microbes thrive on.
Berries, nuts, and cocoa (and even red wine!) contain polyphenols that encourage the growth of ‘healthy’ microbes
Fermented foods containing probiotics These include yogurt, sauerkraut (fermented cabbage), miso (a fermented soya bean paste), tempeh (fermented soya beans), kefir (a fermented milk drink), kombucha (fermented tea), and kimchi (fermented Chinese cabbage), and will have a short-term beneficial effect on your gut microbiota (it lasts only as long as you are eating these foods regularly)
Eating prebiotic foods will help promote ‘healthy’ microbes. These include inulin and fructooligosaccharides that are found in onions, garlic, leeks, chickpeas, beans, and lentils.
Avoid highly processed foods They contain ingredients, such as emulsifiers, that either suppress ‘healthy’ microbes or increase ‘unhealthy’ species.