I am not quite clear what the difference is between your examples and, say, startup CEOs who choose to use stimulants to deal with a crushing workload. Or, ign

I am not quite clear what the difference is between your examples and, say, startup CEOs who choose to use stimulants to deal with a crushing workload. Or, ignoring drugs, every professional boxer runs a risk of long term brain damage, yet they still choose to do it, despite most of them meeting your criteria of not being especially wealthy/ solely doing it for love of the sport.