Beetroot juice boosts stamina by making muscles more fuel-efficient, scientists have found.
Last year the same researchers reported that the red vegetable juice can increase physical endurance.
The study focused on men aged 19 to 38 cycling on exercise bikes. Drinking half a litre of beetroot juice a day for a week enabled them to cycle 16 per cent longer before getting tired out.
Now the scientists believe they understand how the beetroot boost works.
The new research showed that drinking beetroot juice doubled the amount of nitrate in the blood of volunteers, and reduced the rate at which muscles used their main source of energy.
Beetroot juice helped muscles work more efficiently and lowered their oxygen uptake. The same effect was seen during both low-intensity and high-intensity exercise.
Study leader Professor Andy Jones, from the University of Exeter's School of Sport and Health Sciences, said: ''While our previous research demonstrated the benefits of nitrate-rich beetroot juice on stamina, our latest work indicates that this is consequent to a reduced energy cost of muscle force production.
''Since our first study came out we have seen growing interest in the benefits of drinking beetroot juice in the world of professional sport and I expect this study to attract even more attention from athletes.''
The scientists believe nitrate from beetroot juice leads to increased levels of nitric oxide in the body, which affects a range of biological functions including blood flow, hormone levels and cell signalling.
The new findings are published in the Journal of Applied Physiology.
Prof Jones' team studied seven healthy men who were asked to complete a series of knee extension exercises while measuring their exertion levels.
At the same time, a magnetic resonance imaging (MRI) scanner monitored what was going on in the volunteers' muscles.
The test was repeated several times, both after participants had drunk beetroot juice and after they had drunk blackcurrant cordial.
Drinking beetroot, but not blackcurrant, was found to increase blood nitrate levels and reduce muscle usage of adenosine triphosphate, the body's chief energy source. Oxygen uptake by muscles was also lowered.
Article appeared on telegraph.co.uk
No comments:
Post a Comment