British scientists have come up with a novel approach for people needing a bit of extra stamina to exercise for longer – beetroot juice.
Researchers from the University of Exeter have found that drinking beetroot juice boosts your stamina and could help you exercise for up to 16 percent longer.
Their study, published in the Journal of Applied Physiology, said it showed how the nitrate contained in beetroot juice leads to a reduction in oxygen uptake, making exercise less tiring.
"Our study is the first to show that nitrate-rich food can increase exercise endurance," said researcher Andy Jones from the University of Exeter's School of Sport and Health Sciences in a statement.
"We were amazed by the effects of beetroot juice on oxygen uptake because these effects cannot be achieved by any other known means, including training."
The researchers believe the findings could be of interest to endurance athletes and also relevant to elderly people or those with cardiovascular, respiratory or metabolic diseases.
For the study the researchers followed eight men aged between 19 and 38 who were given 500ml per day of organic beetroot juice for six consecutive days before completing a series of tests, involving cycling on an exercise bike.
On another occasion, they were given a placebo of blackcurrant cordial for six consecutive days before completing the same cycling tests.
They reported that after drinking beetroot juice the group was able to cycle for an average of 11.25 minutes, which was 92 seconds longer than when they were given the placebo.
"This would translate into an approximate 2 percent reduction in the time taken to cover a set distance. The group that had consumed the beetroot juice also had lower resting blood pressure."
The researchers said they were not yet sure of the exact mechanism that causes the nitrate in the beetroot juice to boost stamina but they suspect it could be a result of the nitrate turning into nitric oxide in the body, reducing the oxygen cost of exercise.
Jones said this study followed research by Barts and the London School of Medicine and the Peninsula Medical School, published in February last year, which found that beetroot juice reduces blood pressure.