Thursday, May 8, 2008

asthma and doping

Petacchi, the dominant sprinter of the last few years, has been suspended until August by the not-august Court of Arbitration for Sport: for a doping violation involving the asthma drug salbutamol (yclept albuterol in the USA).

In the article, it's claimed that 'Salbutamol can be used to increase an athlete's anaerobic power. '

I have adult-onset asthma, and take salbutamol when racing. The reason I noticed the asthma was that my 5k run times were 10-20% slower at maximal effort, than what training results predicted, with the addition of unusual distress. My training logs go back to 1975, so there's enough data there that I at least am satisfied that the predictions are reasonable. Tests confirmed the diagnosis, so I take it as prescribed now. With salbutamol, performances are back to normal: but I have never been able to measure any performance enhancement, even when running short maximal-effort intervals (400m repeats).

So I took a closer look at the data. The studies that show improvement in anaerobic power used a dosage of 12 mg/day for four weeks. See

That's 12 milligrams a day. To put this in perspective, an inhaler delivers about 200 micrograms per dosage. The anaerobic power improvements require 12 000 micrograms per day. This is equivalent to 60 metered doses from an inhaler. That's a dose every 16 minutes (assuming 8 hours sleeping), for four weeks. It's impossible to hit this dosage except by taking it orally or intravenously. It's clear that Petacchi wasn't doing this.

There are also lots of studies showing that at dosages that can be delivered via inhaler, there are no measurable performance improvements, aerobic, anaerobic or anabolic.
See for example
- The effects of albuterol on power output in non-asthmatic athletes, LEMMER J. T et al,
International journal of sports medicine ISSN 0172-4622 1995, vol. 16, no4, pp. 243-249 (33 ref.)
- The effect of salbutamol on performance in endurance cyclists, Norris Petersen and Jones,
European Journal of Applied Physiology ISSN 1439-6319 (Print) 1439-6327 (Online), Volume 73, Numbers 3-4 / May, 1996

Then there is the question of how the salbutamol dosage is measured. WADA's measure is 1000 nanograms per milliliter (ng/ml) in the urine. This is not a very good measure. See for example this study, which notes:
"Urine cSAL increased with dose and was highly variable, with the peak value observed being 831 ng x mL(-1) after a dose of 800 microg.
Conclusions: Inhaled SAL does not enhance time-trial performance, regardless of dose, and that urine cSAL after exercise is related to dose, demonstrates high variability, and is partially related to hydration status."

Even at 800 micrograms, an order of magnitude lower than a single day's dose of the amount required to produce the anaerobic improvements (and that dosage was repeated for four weeks), it's possible to get very close to the WADA limit. Add in variability, plus the fact that dehydration will artificially elevate the measurement in the urine, and it's clear it's possible to exceed WADA's limit without seeing any performance improvements.

There are a couple more problems here. Metabolization will differ by individual, and by the environment in which it's taken - a fat breathless desk jockey like me is likely to have a different rate from a Tour de France sprinter. Metabolism of salbutamol differs between asthmatics and healthy people too, with the asthmatics showing higher concentrations of salbutamol in urine for the same dosage.

Another thing that's missing is data on the urine concentrations in the subjects who took the massive doses, and showed anaerobic performance improvements. Do they show the same variability of urinalysis data ? What kind of urine measurements were found ?
I suspect their urine would show levels massively higher than the 1000 ng/ml that is currently considered a violation.

Personally I give any endurance athlete the benefit of the doubt in a salbutamol case. A cycling sprinter like Petacchi is a special case, since he could theoretically benefit from the anaerobic performance improvements: but he still has to ride 4-6 hours at moderate to high aerobic pace, just to reach the sprint. Anaerobic performance after this kind of effort has never been tested. Add that to the questions around the current level which is considered a violation, and I think all these salbutamol 'violations' are likely bogus. The potential benefit is too small for the risks.

This 'violation' in particular is nonsense. Even the CAS said, "the adverse analytical finding in this case is the result of Mr. Petacchi simply, and possibly accidentally, taking too much Salbutamol on the day of the test, but that the overdose was not taken with the intention of enhancing his performance. Indeed, it would be an unusual way of attempting to enhance performance to take the prohibited substance after the particular event had concluded."
So.. what is this ? zero-tolerance, as propounded by the imbeciles that propagate the War on Drugs ? It's senseless.

1 comment:

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