I agree what is 10 minutes out of 960 minutes of waking hours. This is based on being active for 16 hours and sleep for 8 hours. 10 minutes of doing some moderate to high intensity physical activity is worth it. To be honest my upper body strength is weak and if I could start with 10-15 push ups (proper form) without stopping that is a great starting point for me. I'm more of a speed and long distance walker.

I also agree that you can be fit at any age. My Unlce is 90 plus, but he's still playing golf (walking), going to the gym every day, and yes he can do a lot more push-ups than me, lol. I told him that I want to be like him at his age.....heck even now.
I've seen this video multiple times, but when I read your title I thought of it right away.