This is incredibly anecdotal, so please take it with a grain of salt- I have a personal history of hitting the gym 5 days a week for ~2 hours for roughly 5 year

This is incredibly anecdotal, so please take it with a grain of salt- I have a personal history of hitting the gym 5 days a week for ~2 hours for roughly 5 years. I've probably taken every caffeine supplement known to man, ranging in caffeine levels from 50mg->550mg and loaded with many other supplements (beta-alanine, creatine). I've never sustained an injury that could be described as over-exertion (Luckily, I hear it is exceptionally common with long term gym-goers). For comparison, an old friend (let's call him Dave) started hitting the gym with me and confessed after 6 months to starting his first cycle of steroids. He developed muscle much quicker than he expected, and so his expectations rose significantly. He sustained a major injury from attempting a bench-press that he was, in every sense, muscularly abled to do- but his tendons weren't. His wrist hasn't been the same since, and he can't bench press anymore. Anyway- coming back to the original point.. I don't believe caffeine has any effect on someone's judgement for "Can I lift that, safely?". The result of hormone abuse might give a false sense of capability, though.