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Megadose of caffeine before training raises testosterone level

Rugby players that are given a hefty dose of caffeine [structure below] before doing weight training produce more testosterone than normal during the training. Sports scientists from the Horticulture and Food Research Institute of New Zealand write this in the International Journal of Sport Nutrition and Exercise Metabolism.


The researchers used a couple of dozen professional rugby players for their trial. Because caffeine in the form of a supplement takes about an hour to reach maximum concentration in the blood, the researchers gave the players caffeine pills an hour before they started to pump iron. The dose varied from 200, 400 to 800 milligrams. A cup of coffee contains about 100 milligrams of caffeine.

Power training increases testosterone production, and even more so if you limit the rest periods between sets. Stress hormones like adrenalin – not cortisol of course – increase this effect, probably because they activate the second messengers in the testes. Second messengers are messenger molecules, in this case ones that make the Leydig cells more responsive to messenger hormones like FSH and LH.

When the players did power training without caffeine, their testosterone concentration rose by 15 percent. When they took caffeine the rise in testosterone was higher. The highest dose of caffeine – 800 milligrams – led to a testosterone rise of a modest 21 percent. Whether this would lead to much more extra muscle mass the researchers were unable to say. It was not so much that the effect was modest, but rather because the caffeine impulse also
led to a rise in the cortisol level – 52 percent to be exact. The post-training testosterone cortisol ratio, a marker for anabolism in the body, was 14 percent lower as a result of the caffeine.

A 600 mg dose of a supplement like phosphatidylserine increases testosterone production after aerobic training, and reduces cortisol production. But you probably have to take phosphatidylserine for quite a while before you notice any effect. The same goes for zinc and calcium supplements.

Doing relaxation exercises after training has an immediate effect, but probably has less effect if you’ve just taken 800 mg of caffeine. Preventing dehydration on the other hand inhibits cortisol production during training and has an immediate effect. As do sugars.

Hmm. Caffeine, water and sugar.

Would power athletes grow faster if they down an energy drink before training?

Int J Sport Nutr Exerc Metab. 2008 Apr;18(2):131-41.

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