The ability for hunters to run a little faster a little farther that a raised hematocrit supposedly confers would have been a powerful survival advantage if it did not come attached to some even more powerful survival disadvantage. If the average male human hematocrit is 40 rather than 50, there is probably a reason, as yet inapparent, that more than outweighs whatever advantage the higher blood count confers. EPO is de facto tolerated in cycling because there is no effective test for its use. The hematocrit limit of 50 percent is set as a safety measure for cyclists. Heavy EPO use killed dozens of cyclists in the 1980s and 1990s because extreme hematocrit levels cause blood pooling and clotting, especially during sleep.
Cycling permits modest caffeine use by competitors and office staff alike.
It also encourages use of corticosteroids to suppress joint damage and constricted breathing. To understand why, one must understand the sport. Knee joints of many competitors would be destroyed if anti-inflammatory therapy was not employed. The de facto permission of drug use by way of setting limits via testing rather than absolute zero tolerance seems to be doing a good job of promoting safety at this time, even if it is at the expense of honesty. But the ideal would be a system that promotes both safety and honesty.