I'm 6'1", fit, 36" waist, usually in jeans. To keep my shorts inflated with cold air at the gym, my shorts went down every time I did a 45 degree seated leg press up to my panties and I found the 3/4 training shorts worked perfectly I think these shorts are more for slimmer people so I would as I have a bit of space like to order a size up, however as the material was medium weight and only slightly stretchy this has often restricted my full range of motion, now I've gone up one size to size 40. It's a little loose and long but given the waist a bit is narrower than I usually like, size 40 after warm wash and dry, shrunk a bit to fit very well Now I can have full range of motion when doing leg workout, protect feet from cold air and prevent the shorts slide down. I'll probably get away with a size 38 and will probably try it next time I order more other colors. Overall I like the quality, the fact that the deeper pockets have zips to keep my ipod or phone from falling out and they are very comfortable and very good quality. Especially compared to other brands I've bought before.