If you let lab rats run as fast as they can for five days a week, they'll become fitter. And if you give these same rats feed containing the miraculous vegetable matter resveratrol, they'll become not even fitter still, but also faster. Researchers at the University of Alberta published an animal study that will probably change the supplement intake of racing cyclists and runners.
Small amounts of resveratrol, a simple compound, can be found in grapes, berries and peanuts. Resveratrol attracted the interests of researchers when they discovered that the compound helped simple organisms to live longer [Cell Metab. 2008 Aug;8(2):157-68.] and that it increased fat burning.
We don't know whether or not resveratrol can help people to live longer, but researchers have discovered that resveratrol imitates the effects of training and improves the glucose metabolism in humans.
Fundamental studies have shown that resveratrol can be used for weight loss because it interferes with how fat cells function – certainly in combination with quercetin, genistein, [J Nutr. 2007 Dec;137(12):2668-73.] or - better still – with both quercetin and genistein.
In animal studies resveratrol also helped to improve physical performance. It increased the rate of metabolism in dwarf lemurs and increased endurance among rats.
The researchers at the University of Alberta wondered whether supplements with resveratrol would help to improve endurance in humans.
For 12 weeks, the researchers gave male rats normal feed [Control] or feed with resveratrol [RESV]. The rats in the resveratrol group ate 146 mg resveratrol per kg bodyweight daily. The human equivalent of this dose is 14-23 mg per kg bodyweight. [That is probably too high. Most people can eat only a few hundred milligrams of resveratrol per day without any side effects].
Half of the rats in both groups ran almost daily on a treadmill until they were exhausted [ET]. The other half didn’t train [Sedentary].
At the end of the 12 weeks, the bodyweight of the resveratrol group was just a tiny bit lower. But the rats’ endurance had been greatly affected. The supplement with resveratrol enabled them to run for 21 percent longer and cover a greater distance.
The heart muscle worked better because of the resveratrol supplement in the feed. The ejection fraction – the amount of blood that the heart muscle pumps around with each contraction – increased.
As you can see above, the lab animals that had been given resveratrol burnt more fat when resting. The figures below show that, because of resveratrol, the animals were able to burn more glucose and more fat when they were active.
The above table shows that resveratrol makes the genes related to the fat sensor PPAR and the fat metabolism work harder. The table also shows producers of supplements how they can increase resveratrol’s ability to improve physical performance.
"These resveratrol induced adaptations are likely to contribute to the improved endurance capacity of ET rats and we conclude from these findings that dietary supplementation of resveratrol during exercise improves exercise performance beyond exercise alone", the researchers concluded. "This strategy may have clinical utility in many situations where improved physical performance needs to be augmented due to the patient’s inability to perform intense exercise."
J Physiol. 2012 Jun 1;590(Pt 11):2783-99.