Boxing has been estimated as approximately 70-80% anaerobic and 20-30% aerobic. Anaerobic means to conduct an activity without oxygen. Anaerobic exercise, like boxing, stresses the muscles at a high intensity for short periods of time.
I see similarities between parkour and boxing. I would estimate that training parkour is 70-80% anaerobic too. I think that boxing will bring me the sort of discipline and commitment to training that I need.
On top of that, my friend wants to try out boxing too and he reckons he could wipe the floor with me...!
Lets the games begin ;)