Beets can actually improve running times. They have legitimate performance enhancing properties that cut down race times and improve muscle function. Packed with vitamins like iron, stuffed with folic acid, and chock full of antioxidants, concentrated beet juice is well known in the running world as a legal performance enhancer.
Extracting juice from the beet root gives you a liquid rich in nitrate. Once in the body, nitrate metabolizes into nitric oxide that, although the science is still unclear, appears to have powerful positive effects on endurance.
In 2010, a study by Katherine Lansley at the University of Exeter tested oxygen intake and consumption during a series of walking and running exercises. Nine men consumed 17 ounces of beetroot juice over a period of six days, and their results were compared with a control group who drank a placebo liquid. When running, the men who drank beetroot juice consumed less oxygen at multiple different speeds. They were able to run 15% longer on a treadmill when pushed to exhaustion. Efficiency and duration, it seems, improved.
In St. Louis researchers found that eating whole beets, not just concentrated beet juice, led 11 runners to finish a 5km race faster than a group that didn’t consume beets.
Another later study in 2012 by Noami Cermak and others compared beetroot effects over a similar six day period. Cyclists, not runners, were tested this time. Over the course of a 10km cycling trial, power output improved by 1%.
The jury is still out. Studies on beets that have been conducted on high-level endurance athletes show that the effects are less prominent. Perhaps intense training maximizes whatever mechanism beets have an effect on, so lower-level athletes may benefit more.
Regardless, the existing evidence is promising, and beets certainly can’t hurt. Give it a try for yourself and see if your results improve.