Joints and tendons can only take so much either on a once or twice hit per wk on a body part.i find a 4 day routine best and some pros labrada and take out that he used anabolics,swore by pre and post contest offseason a 4 day as such,trained mon,wed,fri,sun,,some say 3 day is optimal.everybody's genetic strength,recuperation,duration,response,is going to be different anyway,find a routine and follow it till it gets stale then tweak it but nothing drastic,cause as most responses already said injuries can occur and burnout.