Jeez, we’ve discussed all this a long time ago on the salbutamol thread. Many studies have reported it can increase muscle strength/anaerobic power, relatively few studies have shown an effect on endurance. I and others pointed out very early in that thread that you wouldn’t need a weight loss drug during a GT—that this was a valid argument against the conclusion that Froome had intentionally been doping with it--but other metabolic effects suggest it might be used for recovery. And as always, whether a substance is used for PE effects depends not so much on what those effects are as the perception of the riders of what those effects are. Even if salbutamol’s PE effects are minor compared to other substances, you have to weigh that against the fact that they’re “free”, i.e., a rider can take it up to a certain amount with no consequences. Maybe salbutamol would be worth five seconds on a climb, whereas EPO/blood doping would be worth two minutes, but if you can get those five seconds with no possibility of a positive test, why wouldn't you take them? Marginal gains, right, isn't that the mind-set?
Wrt Parker’s chart of cancer effects, data like that don’t necessarily mean studies contradict each other, they may just reflect different conditions. What was taken as an indication of cancer? What other foods were taken with the one focused on? What was the age of the cohort, lifestyle factors, etc., etc. Obviously, demonstrating that some substance or treatment is a causal factor for cancer is far more difficult that demonstrating an effect on a physiological parameter that can be measured immediately.