I guess we're all gentlemen over a certain age.
I have kept fit all my life, mainly by running. I also do a fast but light weight routine on the off days. I recently dropped my running from 45 minutes down to 10 minutes of high intensity bursts and have felt better for it. If I don't fancy it then 20 minutes of brisk walking up hill will do. The dog gets a couple of hours a day but at a slower pace (he's my main hobby.)
I've had to admit to myself that I'm slowing down.
I needed something for toning that I could take into later life and I think I've found it in the 7 Tiger Moves. These can be made as hard or as easy as you like. They involve dynamic tension, ie working one muscle group against another for a super efficient workout without weights or special equipment and no danger of dropping, falling or jarring. The secret is to work out mindfully concentrating on the muscles you want to target and I'm sure they can benefit anyone whatever the effort.
Dynamic tension can be used to build muscle too but the effort and time required equates to a workout as serious as any gym routine. I recommend a light to medium regime for conditioning and rejuvenation only. Here are the 7 Tigers.