If exercise was a drug most clinical exercise studies would be considered a Phase 0 study. Phase 0 is where a group decides if a drug protocol has any future and merits further study. Phase I is where safety testing is done, usually at doses too low to have any real projected benefit. Phase II is where science cured all cancers 20 years ago. In mice. Phase II is where most drugs fail. The vast majority of drugs never get past Phase II. Phase III - a few years, a few thousand participants, and a few hundred million dollars later - is the stage where a drug is nearly ready to be released to the public. If Crossfit were a drug it would be in Phase IV, aka post-marketing surveillance. Olympic weightlifting would be Phase V.
The obligatory photo of a scientist staring at a beaker of blue fluid:
