I think the lion has the most muscle mass percent of any land animal ever tested:
http://static.comicvine.com/uploads/original/10/106762/3889030-8716730068-perce.jpg
They are nearly pure muscle, stocky, short and stout:
Tigers are thin, lithe and long, some records upto 12 feet, thats 2 feet longer than a polar bear:
Of course you cant see a male lions because it is hidden by the mane, but only one man in all of science had taken the mane off and dissected the lion in an autopsy and compared it to a tiger, M.D Andrew howe, he stated beneath the mane lays a massive and huge hump of muscle at the shoulders that exceeds that of the tigers...dont know why a lion wouldn't have more muscle logically anyway, they thrive in the desert as well, hence the heat would strip away most of the excess fat.
They both have their strengths, the tiger is the stronger grappler as they soley bring down buffalo, guars and some times even rhinos, in the clinche he can control the lion better and throw him down easier, the lion is the stronger striker, he can knock off a pumas head, smite a jaguar dead, break the neck bone of a zebra and donkey cave in the skull of a black or brown bear, or use his paw to drop a horse, camel, buffalo and eland:
African Lions Striking Strength: - History Forum ~ All Empires
Two live different lives, one likes fame and war, (lion) the other solitude and terror (tiger).