This is a bit difficult. If you just run, do aerobics and ride a spinning bike, you should be able to do it. As for strenuous exercise such as weightlifting and push-ups, I personally suggest that you don't refer to the answers here, because we don't know your physical condition. I hope the landlord will go to the hospital for a check-up, or consult the attending doctor who performed the operation at that time. The problem with your head is no small matter. The landlord is cautious, be sure to go to the hospital to ask clearly, and wish the landlord health!