Join Date: Mar 2008
Location: Water-boarding some liberals...
As long as you eat a lot to keep your body fueled and you listen to your body when it is being overstressed, you should be able to get away with some extra stuff on your days off.
Since you are already working with weights on MWF, I would suggest you stick to light stuff on TTh. Those would be great days for extra stretching, light calisthenics and maybe some short duration HIT training. You're already taxing yourself pretty good, so what you do on your days off should be geared around supporting your main focus without overdoing it.