Well, beets and beet juice were hypothesized to be performance enhancers due to due to their high concentration of dietary nitrates. The theory is that nitrates in beetroot juice may act as a vasodilator, helping improve blood and oxygen flow to muscles.
Interestingly, our traditional view of dietary nitrates is pretty poor – they’re found in high levels in processed meats like bacon and sausage, and have been linked to serious health problems like increased cancer risk.
However, there is an interesting paradox that dietary nitrates found in vegetables seem to have beneficial, rather than harmful effects. It is unclear exactly why nitrates cause harmful effects from certain sources and beneficial from others, but it is possible that nitrates act in combination with other components inside vegetables which protect us from any negative effects and create a positive impact.
So what about endurance performance?
There have been several studies done over the last few years looking into the effects of beet juice on endurance performance. In a quick literature review, I found 8 studies between 2010 and early 2013. And 5 out of those 8 studies showed a beneficial impact of consuming beet juice on performance, in the area of around 2-4% improvement in time trial performance in both cycling and running!
Note thought that these studies have been on mostly well trained athletes. In untrained athletes, the difference that beet juice makes would likely be negligible – you’d be better off simply training more consistently! In addition, the potential benefit may only extend to your specific training discipline. For example, when researchers looked at the impact of beetroot juice on cross country skiers in a 5k trial, there was no effect – perhaps because running wasn’t their preferred modality (Peacock et al, 2012).
Based on these studies, it seems plausible that beetroot juice (or even the beets themselves, though I don’t picture that being a very pleasant pre-workout snack) may provide a slight edge for highly competitive athletes. And considering there’s no major downside (aside from some potentially purple poop or temporary tooth discoloration) – it might be worth it to give it a try.
Before I go further – please, please – if you decide to use beet juice, practice with this during a long run or ride in training before using it in a race. Race day is not the time to introduce something brand new!
How much should I eat or drink?
The optimal dose based on this research is a half liter of beetroot juice or 3 to 4 cooked beets, equating to 300-500 mg of dietary nitrates, about 3 hours prior to a long training session/race (blood levels peak in 2-3 hours and stay elevated for 6-9 hours). Going back to those products at the expos - there are some newer beet juice “shots” available which boast a more concentrated source of nitrates, making it easier to get the amount for potential benefit without having to drink a half liter or eat such a large amount of fresh cooked beets.
Also, please stick with dietary sources of nitrates in beet juice rather than searching for a pill/supplement. Nitrate salts and pills can cause potential side effects which may be dangerous when consumed in high amounts, causing problems like a severe drop in blood pressure or passing out. And, perhaps most importantly, people can mistakenly purchase nitrite salts (emphasis on the i), rather than nitrate salts, which can cause extremely dangerous side effects in even small amounts. While nitrate is nontoxic up to rather high levels, nitrite can cause harmful effects at even low levels. Bottom line – stick with foods!
One more word of warning that may apply to a few of you: a very high intake of dietary nitrates may cause a drop in blood pressure. If you struggle with low blood pressure or are on a blood pressure medication, you should approach your doctor before adding beetroot juice to your regimen. Also, be aware that beet juice or beets can cause temporary tooth discoloration and purplish poop! (The things we do as athletes…)
Share with us: Have you ever tried beet juice as a performance enhancer? What were your experiences?