Average person doesn't work out at all, FYI
Of course they do, its required for a healthy livestyle. This habit is endagered nowadays due to work focussing more and more on desks jobs and the better infrastructure to avoid walking, running and cycling.
As I said, Ian is above average
compared to these trends nowadays. I used to ride to school with my bycycle every day and swam once a week. I wasn't buff in any way and had no muscles, but I was like Ian, lean, slim, average, a 4 or 5 bodywise.
So Ian needs to be Stephen King with the appareance of Brad Pitt to be a 10 but Lena is a 10 because she is hot...
That's how the double standard goes. Ian needs to be successfull to get to the top, Lena could get away with that by marrying a rich man. She is still quite intelligent and can converse, hence Axel and Seymour appreciate her over someone like Ivy. Once she is rich and someone like Agnes at old age she'd made it.
Even a loser stoner Ian is at least a 3. At his worst, he's better than Stan who is probably a 2 (because he's not too ugly or covered in acne). 0 means totally unfuckable = smells bad, covered in zits, socially inept, dumb, bitter, no hobbies, etc. Not just one of those qualities, but all of them.
True, the Loser path is currently not fleshed out enough and Ian needs possibilities to sink to new lows for the remaining chapters. The best way for the 0 is to let him be cucked (and him not being okay with it), lose his job, lose his friends etc.