On January 1, 2024, will kick in that officially bans tramadol, an opioid painkiller. It鈥檚 been a long time coming: the abuse of tramadol has been an open secret in cycling, with about its use by Team Sky and British Cycling. 鈥淚t kills the pain in your legs, and you can push really hard,鈥 former Team Sky rider Michael Barry . found tramadol in 4.4 percent of all samples from cyclists, leading to worries that tramadol-addled riders would cause crashes in the peloton. For some athletes, like , tramadol was a gateway to full-blown opioid addiction. The International Cycling Union banned it in 2019, but WADA continued to take a wait-and-see approach.
The data that finally changed WADA鈥檚 mind has in the Journal of Applied Physiology, where it鈥檚 free to read. A group led by Alexis Mauger of the University of Kent in Britain put 27 highly trained cyclists through a series of performance tests with either 100 milligrams of tramadol (a modest dose: Kirkland was taking as much as 20 times that amount at once) or a taste-matched placebo. The riders were, on average, 1.3 percent faster in a 25-mile time trial when taking tramadol. WADA鈥檚 rules require that a substance fulfill two of three conditions to be banned: it enhances performance, has the potential to harm the athlete, and violates the spirit of sport. Mauger鈥檚 data sealed tramadol鈥檚 fate.
That鈥檚 the simple part of the story. Or at least, the relatively simple part. Admittedly, previous studies of tramadol鈥檚 performance-boosting effects have produced mixed results. Mauger and his colleagues argue that these previous studies have featured performance tests that weren鈥檛 long or hard enough for pain control to matter, failed to exclude participants who had side effects like vomiting from the drug, or muddied the waters by having cyclists complete cognitive tests while they tried to race. It鈥檚 also worth asking whether the benefits of a painkiller might be exaggerated in a test where the subjects are forced to fixate on their own discomfort, giving continuous ratings of exactly how much they鈥檙e hurting, compared to the real world. Still, the new results make a strong case that tramadol boosts performance and should thus be banned. The harder question is why it works.
In 2010, Mauger published showing a 2 percent boost for cyclists taking a simple dose of Tylenol. He has followed up with other studies using various techniques like saline injections to manipulate exercise-associated pain. In Mauger鈥檚 view, pain is one of the sensations that causes us to slow down or stop during endurance exercise, so the tramadol results make perfect sense.
Not everyone agrees, though. When I wrote about Mauger鈥檚 research on pain in 2020, I noted that other researchers such as Walter Staiano and Samuele Marcora believe that subjective perception of effort (鈥渢he struggle to continue against a mounting desire to stop鈥) is more important than pain (鈥渢he conscious sensation of aching and burning in the active muscles鈥). Staiano and Marcora have published supporting their contention that we quit when effort maxes out, even when the pain we鈥檙e experiencing is still tolerable. There may be ways of reconciling these two views: perhaps the cognitive effort of managing increased pain makes exercise feel more effortful, for example. But it鈥檚 still an open debate, which makes any new data on the question particularly interesting.
And the details of Mauger鈥檚 data, it turns out, are indeed curious. For starters, here are the five-mile splits for the tramadol (open circles) and placebo (closed circles) conditions in the 25-mile time trial:
The tramadol riders are pulling ahead right from the first split, and continue to widen their lead throughout the trial. One interesting wrinkle: riders who scored higher on a psychological test of pain resilience鈥攖hat is, those who felt they had better ability to regulate their emotions and thoughts about pain鈥攖ended to get a bigger performance boost from tramadol. To be honest, this is the exact opposite of what I expected: I would have guessed that those who struggle most with managing pain would get the biggest benefit from reducing it.
Immediately before the time trial, the cyclists did a 30-minute ride at a hard but steady predetermined pace, while rating their perceived effort every five minutes and continuously noting any changes in their perceived pain. Here鈥檚 what that data looked like (pain above, effort or RPE below):
Now we have a conundrum. Tramadol, an opioid painkiller, appears to have had no effect whatsoever on the pain experienced during cycling. On the other hand, it significantly lowered the perception of effort, which in turn鈥攁s predicted by Staiano and Marcora鈥攊mproved performance. Mauger and his colleagues aren鈥檛 sure how to explain this: they suggest that the continuous self-reporting of pain, as opposed to being asked about it every five minutes, might have made it harder to pick up small changes. I鈥檓 not sure what to make of this finding, but it reaffirms my sense that we still have a lot to learn about how pain and effort and other related constructs like mental fatigue influence our performance.
As for tramadol, its new status will end the longstanding ambiguity about its use. Nairo Quintana, the Colombian cycling star, 鈥攖wice鈥攄uring the 2022 Tour de France, and was stripped of his sixth-place finish. But it was deemed a medical issue rather than a doping positive, since tramadol wasn鈥檛 banned by WADA, and thus carried no suspension. Starting next year, any athlete caught using it won鈥檛 be so lucky.
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