Comment by TacticalCoder

Exercising and building muscles when you're young is the very best thing you can do. These muscles shall stay for a very, very, very long time.

As a kid I was doing BMX, tennis (still do some), swimming then as a teenager street skateboarding, rollerskating, MX (motor)bike, tennis.

Now I'm an old man (52 y/o) and I don't do much sport. Some MTBing (still can do a wheelie and trackstand, ah!) but really not much. I drive my old sportcar (yup, that is physical and you do sweat). Some tennis while on vacation. And shooting at the range (and, yup, that is a bit physical too).

But I really don't do much. I'm of this school: "Qui veut voyager loin ménage sa monture" (french) which translates to "He who wants to travel far takes care of his mount.".

The number of friends my age who destroyed their bodies by continuing to exercise as if they were 20 or 30 years old is beyond belief. I think I'm one of the only one who didn't get knee surgery yet.

Running is terribly bad as you get older. Hockey (ice or grass): body destroyer. BJJ? Don't get me even started.

My doctor says "sport is death". He knows.

Tennis is particular in that you can really play it at your own pace: just pick someone your age and hit the court gently. No crazy rallies, just fun: I'm not going to win Roland-Garros at 52 y/o and you ain't either.

And there's something else among all of my friends who regularly do sport: as soon as they stop for a few weeks, they get fat.

Which is a problem I don't have.

So exercising a lot in your teens, 20s and 30s: sure. That shall build you muscle you'll keep for decades (my legs are still very strong).

But slow down after that or you'll break your body and then get fat as soon as you have to stop exercising (for example because you have to get knee surgery because you destroyed your knees running).

Something something about Buddha / Siddhartha warning to not put too much tension in a lute's strings or in a bow's string. There's a lesson in there.

You have your age, deal with it and act accordingly.