hey, i'm curious if anyone here trains without equipment? i've been interested in building muscle mass sans weights for a while, as it seems very economic and a lot more practical. i like to do isometric and isotonic exercises utilizing my body as the resistance. a simple example being, having your hands outstretched and pushing on one another as hard as possible, or sitting and pushing your knees together while providing resistance with them. http://www.angelfire.com/ny5/shenandoah/OBB/OBB.html, this site has a very comprehensive program that i've found extremely useful and i hope you guys can get some ideas from it too.
also, if anyone has information concerning vrt or dvr exercising i would be very grateful because i can't seem to find much information on the subject and can't really grasp that sort of training.
one last question, what are the primary muscles used in cycling and what exercises could i do to develop them most effectively?