Thursday, May 20, 2010

Beetroot boosts stamina, scientists find

This was not a double-blind study of a normal population so could be yet another false start. And note that with a sample size of only 7, nothing the researchers found would have been statistically significant. And what the devil are "knee extension exercises" and how do they relate to anything else? I didn't know knees were extendable.

Brits are quite strange about knees. The reason they wear long pants on even the hottest of days is that they think people might see that their knees are knobbly. Nobody seems to have told them that ALL knees are knobbly.

Beetroot is a staple of the Australian diet. We have it on our hamburgers and in our salads -- but I personally loathe it and never eat it. So Australians generally should be full of stamina? First I've ever heard of it. Full of beer I could believe.

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.


Moderate drinkers the healthiest

A commendable sophistication about the probable chain of causation below

Those who enjoy a glass or two of wine with their dinner or a brandy before bed are much healthier than others, a study has found. But, before you pour yourself a large one, read on.

Although the research shows moderate drinkers are slimmer, less stressed and have a more positive outlook, alcohol, alas, has nothing to do with it.

Their rude good health is more likely to be thanks to the fact that moderate drinkers also tend to have a healthier diet, exercise more and have a better work-life balance than both teetotallers and heavy drinkers.

The conclusion contradicts the results of numerous other studies which have credited small amounts of alcohol with large health benefits. It will also come as a blow to the millions who tell themselves they are looking after their health when they open a bottle of wine with dinner.

The French researchers subjected almost 150,000 men and women to a series of tests at a Paris hospital. They were also asked about their education, job, amount of exercise they did and how much they drank.

The volunteers were split into four groups - teetotallers, low-level drinkers (who had less than 10 grams of alcohol a day) moderate drinkers (10g-30g a day) and heavy drinkers (more than 30g).

In Britain, 8g of alcohol is classed as one unit. Half a pint of ordinary strength beer counts as one unit, while a standard pub measure of spirits or a small glass of wine equates to one and a half units.

As other studies have shown, those in the low and moderate groups had better general health than those who never drank or drank large amounts. Men who drank moderately tended to suffer less from stress and depression, were slimmer and had a lower risk of heart problems. Female moderate drinkers were also healthier, had smaller waists and lower blood pressure than others.

For both sexes, moderate drinkers were also found to have higher amounts of 'good' cholesterol, or high density lipoprotein (HDL), in their blood.

Writing in the European Journal of Clinical Nutrition, Dr Boris Hansel, of the Hospital of Pitie-Salpetriere in Paris, said most previous studies had failed to take into account the fact that those who drank ensibly tended to also take care of their health in other ways.

He said this group often had a more educated approach to their health. They may exercise more, eat fruit and vegetables more frequently or take up yoga to cut stress levels. He added: 'These findings suggest that it is not appropriate to promote alcohol consumption as a basis for cardiovascular protection.' However, he did concede that 'pleasure' was the best justification for light drinking.

June Davison, of the British Heart Foundation, said that while small amounts of alcohol may be beneficial, large quantities can cause high blood pressure, strokes and some cancers.


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