Want More Endurance? Try Beetroot Juice Studies suggest it gives athletes greater endurance 5 comments Comments Beetroot juice gives athletes some extra oomph, two new studies suggest. (AP) (User Submitted) – A couple of studies done by Exeter University have shown a 20% increase in endurance by athletes drinking beetroot juice. Average athletes won't turn into an elite ones overnight, but they could see benefits such as being able to exercise longer because of the effect the juice has on muscles. One theory: Its high nitrate levels allows muscles to work with less oxygen. Read the full article.