As part of my personal performance portfolio in sports science, i was monitoring my fitness/muscle mass before and after the season, (county rugby) And last year thanks to trials out of season, and pre season fitness, My biceps went from 11 itches to 14-15, might not seem like much but its a big improvement. And after the season just finished they went to 16, And i think its more or less down to trials, And my forearms are more than a foot now two! And it does help with biking, especially free ride. Were its Manley developed around core strength, (and not falling off)