Follow this routine: http://youtu.be/4BOTvaRaDjI
Doesn’t take a lot of time, but is challenging and works. The focus is all on the posterior chain (read back, glutes, hamstrings).
This will make you a better handler on the bike, better climber, and help cut out lower back pain. These are the muscle groups that cyclists often ignore, and pay the penalty for.
Do some foam rolling and stretching after the foundation routine.
THE VIDEO IS Not working, what can I do?