If you have that much trouble finding even that much spare time, then just get up a few minutes earlier in the morning, or go to bed a little late at night. The five rites are the expressed purpose of restoring health and youthful vitality to the body. Other factors help determine whether you will dramatically transform your physical appearance, as I have done. Two of these are mental attitude and desire. You've noticed that some people look old at 40, while others look young at 60.
Mental attitude is what makes the difference.
If you are able to see yourself as young, in spite of your old age, others will see you that way too. Once I began practicing the rites, I made an effort to erase from my mind the image of myself as a feeble old man. Instead I fixed in mind the image of myself when I was in the prime of my life. As I put energy in the form of very strong desire behind that image. The result is what you see now.