You must restrict weekly workouts to no more than four. Your muscles need time to recover and grow. Working out too frequently could lead to injuries, which will end up being counterproductive as it comes to your end results.
If your training regimen has reached four days weekly, then try to avoid having more than one pair of consecutive down days. Your body will build and recover better with the down days spread out. If your life and schedule make this impossible, do not lose any sleep over it though, as you are still working out four days a week.