By now you’ve heard of probiotics, but what are they, and why are they good for runners? Bacteria found in some foods – the live cultures in yoghurt, for example – are probiotics that help balance the microbes in the intestines. These friendly bacteria help to ease bloating, gas and other uncomfortable issues. Now, evidence suggests that probiotics confer other health benefits, including fighting off colds, improving heart health – and ending mid-run pitstops. ‘As more strains are tested, the scientific data backing probiotics grows,’ says Mary Ellen Sanders, a consultant who helps develop accurate health claims about the good-for-you bacteria. Probiotics form naturally during fermentation, and some companies have begun fortifying foods with good bacteria, making it easier to get a daily dose. So start loading up with probiotic-laden foods to boost your health and your running.
Stop the pitstops
Your mid-run need to find a loo – fast – could be the result of a condition that strikes endurance athletes, particularly runners, called leaky gut syndrome. ‘A side effect of exercise is that it causes the cells lining the intestinal wall to pull apart a little bit,’ says Philip Calder, professor of nutritional immunology at the University of Southampton. Gaps between cells allow substances from the gastrointestinal tract to leak into the bloodstream, triggering mid-workout bowel distress. Recent research suggests that probiotics can help correct the problem. A study published in 2013 in the Journal of the International Society of Sports Nutrition analysed blood samples from trained cyclists before and after intense exercise and found fewer instances of leakage in athletes who’d taken probiotic supplements for 14 weeks. Probiotics help keep gut cells together, which strengthens the intestinal wall, says Calder. And keeps runners out of the bushes.
Bolster your immunity
Vitamin C has long been the go-to nutrient for boosting immune systems during periods of hard training. Now, runners can also turn to probiotics. ‘There’s strong evidence that probiotics reduce the duration of upper respiratory infections and may even decrease how often they occur,’ says Sanders, citing research in Europe, the US and China. In one study, published in the British Journal of Sports Medicine, 20 elite distance runners who supplemented with probiotics during four months of winter training had milder symptoms and shorter bouts of respiratory illness. It’s not clear how probiotics fight invaders, Calder says, but studies indicate that the bacteria tell the immune system to work better. ‘I’ve seen improvements in my runners who start taking probiotic supplements or targeting probiotic foods,’ says Cara Marrs, a nutritionist, runner and race director. ‘There’s a reduction in the two-day colds that are so common during a tough training cycle.’
Improve heart, mood and weight
Though the research is preliminary, studies suggest probiotics’ health benefits may have a broader reach. In research conducted at McGill University in Canada, subjects’ LDL or ‘bad’ cholesterol levels were 11.6 per cent lower following nine weeks of probiotic supplementation. And studies conducted at the University of California and the University of Toronto have shown a link between probiotic intake and diminished anxiety. Additionally, studies with mice indicate probiotics could contribute to weight loss. Obese people have a different bacteria profile in the gut from lean people, says Calder. When a group of mice had their gut bacterial makeup altered with probiotics, their weight changed. ‘You can actually make an obese animal lean, and vice versa, by swapping bacteria,’ says Calder, who adds that human clinical trials are probably still years away.
Or maybe pop a pill. While researchers use supplements to isolate the effects of probiotics, runners can get a health boost from food sources alone, says Marrs. But frequency is key: probiotics in the gut die off quickly unless there are reinforcements. Runners should aim for a daily dose from probiotic-rich foods such as yoghurt, miso and kimchi. The time to consider a supplement is when you’re running longer distances or feeling run down, says Marrs. If you decide to take a pill, look for products like Innate Response and New Chapter, which derive their probiotics from whole foods; these are better absorbed by the body. And the usual food rules apply: limit your intake of refined sugars and processed items; and target fibre-rich foods. The combination helps boost the balance of friendly bacteria in your gut. ‘A healthy diet is primary,’ says Sanders. ‘Once that’s in place, probiotics may help.’