I recently saw a documentary on San Quentin prison, which is one of the many that have removed their weight training facilities for inmates. Despite the lack of weights, a lot of dudes there were pretty massive and very muscular. This is where the question of plausibility of calisthenics building mass comes into play... I noticed serveral dudes who were interviewed had very large, well-shaped pecs. As far as lats, biceps, and triceps go, I think it wouldn't be too difficult to get a nice amount of mass from calisthenics such as pullup variations and dips... but as far as chest, all that is really available is pushups, which is something these guys do a shitload of. Is it actually possible to gain significant pectoral mass through pushups? There were a few dudes shown doing bench press type exercises by laying under a picnic table, and pushing it up while another inmate lay on the table... This would obviously work pecs to some degree, so that could serve as an explanation... But if you're laying on the ground, your arms can't go past 90 degrees, therefore any bench press type exercise being done in that setting would be really more like the higher half of a bench press, which is what hits more triceps than chest from my understanding. Anybody got any ideas on this?