Hard to say yes or no. I'm 43 & train 6 day's a week; however, I only lift 5 day's, each body part once a week. Lift M-F & do cardio Mon. Tues. Thurs. Fri. & sat, then Sunday completely off. I have also worked out most of my life, so my body is use to the stress.
If someone over 50, who has never worked out, asked if training 5 day's a week was to much, I would say absulutly. Without knowing the history of the person asking the question, I couldn't give a yes or no answer. Also, if you have never worked out, I agree with extremelyhuge (above) as to seeing your doctor before starting anything.
Sorry to ramble on, thats just my opinion.