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Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

24.11.2008

More fat burnt in a cardio session with salbutamol

A dose of salbutamol – the active ingredient in medicines for asthma such as Ventolin – doesn't increase the total amount of energy you use during a cardio training session by much, but it does change where you get the energy from. According to a study by sports scientists at the Université d'Orléans, athletes burn more fat if they cycle with a salbutamol capsule in their system.

Study
Salbutamol is a banned substance in the sports world. Cyclists go faster if they use salbutamol, but it's not known where the extra energy comes from. The French decided to fill this knowledge gap by doing an experiment with eight reasonably trained amateur athletes. The subjects cycled for two hours at sixty percent of their VO2max – once with a placebo and once with salbutamol, containing 4 mg of active ingredient. The test subjects cycled a couple of hours after taking the pills.

Results
The graph below shows how much energy the test subjects used. PLA = placebo; SAL = salbutamol.

The number of joules that the cyclists burned rose slightly as a result of the salbutamol, but not by a significant amount. However, when the researchers examined whether the cyclists derived their energy from fat or carbohydrates, they noticed that salbutamol promoted fat burning and reduced carbohydrate burning.

The researchers also measured the levels of insulin, growth hormone and ACTH (the messenger hormone that instructs the adrenal to make the stress hormone cortisol) in the subjects' blood. Salbutamol reduced the production of ACTH. The salbutamol also resulted in a small, not statistically significant rise in the growth hormone level.

Conclusion
The researchers concluded that there was little ergogenic effect to be seen from their experiment: "Our data show that energy metabolism and regulation are not significantly affected by acute therapeutic salbutamol intake. Further studies will be necessary to study the effect of salbutamol on these parameters in other conditions, in particular in elite athletes under longer exercise durations."

Well - we dare to disagree. Substances and methods that stimulate the burning of fat and save carbohydrates are always of interest to endurance athletes, even if the total amount of energy burned does not increase. And perhaps even more so when it comes to the reducing effect on ACTH of salbutamol.

Sources:
Eur J Appl Physiol. 2008 Oct 17; [Epub ahead of print].