I have been running for about 4 years and recently graduated high school. Decent runner, not terribly fast at my peak (4:41 1600/16:48 XC 5k), but I've never been able to wear split shorts for more than a mile without chafing. My legs are definitely bigger than other guys on my team, but they're not huge, nor am I overweight (~158 lbs and 5'10"). I've found that half tights work a little better for me but I still want to have the ability to wear whatever I want. My legs haven't seemed to slim down at all through my years running. I've read stuff about "q-angle" and have begun questioning if I'm even genetically capable of wearing split shorts without chafing.
Also, I've tried Body Glide and Nut Butter and neither has seemed to work. I'm not really sure what to do as an alternative. I usually just ignored the pain during 3mi/5k races but wearing split shorts for training/workouts isn't really feasible.
Any similar experiences would be appreciated if you want to share.