Generally speaking, most "Real Jocks", are of athletic build. That is, to meet with much success in about any athletic endeavor, one has has to have a degree of muscular development (chess and shooting not included). Now, McPhelps (my making fun of his poor diet) is a gifted swimmer, but, nonetheless, he's athletic in build. In the very physical sports, most of the guys are what I'd call "hunky", with an abundance of strength and conditioning specific to their sport. In the power sports, and sports of cosmetics, like bodybuilding, size, and strength, along with great lines, are the hallmarks of their sport.
No one can argue that a guy 5'10, and 135 is muscular. He may have a level of cardiac endurance, but, likely, is not "fit" in other areas of fitness. A basketball player at the collegiate level is clearly athletic, however, and almost certainly is trained with resistance, and has a wide number of factors that make him very "fit", much as a competitive bodybuilder is EXTREMELY fit from doing hours of a wide variety of training from endurance cardio, cardio intervals, to circuit training to strength training. They, truely, are amongst the fittest of the fat.
Guys that are well-built (a product of testosterone (the male hormone), and years of work, as well as a careful nutrition and training), are often exceptionally fit when they include cardiac activity in their training (their cardiac threshold becomes extremely high due to all the muscle and support systems they have).
The lack of food, and the lack of testosterone, encourage small, weak, and frail; typically with much less confidence, but not always. For me, a well-built, fit, and bright, man is so much better than an under confident, weak, skinny, and frail, .... part of a man. If I wanted to date women I would. Being muscular, confident, built, witty, and fun, are all part of what testosterone (maleness) brings.
To me, someone who won't; who doesn't engage in physical work (be it weights, or labor), and who is meek and frail, is just the weaker of the species. They typically are whiney, as well, and very self-centered, in my personal experience. It's just not something I'm personally attracted to. I'm not attracted to fat folks, either, however, because, to me, they represent laziness, a lack of action / discipline, and willing self-abusive behavior (you don't wake up one morning 400 pounds)...folks who fail to take personal responsibility for their health. It's a huge turn off. When I look at them I see lazy, and unwilling to help themselves...it's a huge turn off.
You asked, and I answered. I like them big, and strong, and confident, and fit, and witty, and bright, and smiling, and fun, and out, and a good time. Skinny, whiney, low-esteem guys...well...someone else can have them.