People seem to be missing the point. 100's and 50's are different. In it's simplest form:
0n 100's you slow trot and walk
On 50's you extended trot and trot.......trot..........trot....canter.....trot! rinse repeat.
50's are MUCH more intense. I could ride a 100 mile ride one day and the next go on a 5 miles hike. After a 50 I couldn't even move for two days because the pace was so fast and it just drains you.
