As a father of 3 sons, what are the best to teach them survival skills?

That's so lame in a world that is more Intellectual. I suggest you demote yourself as their brother, and find a good mentor for them as only the smart ones can survive and the rest will get enslaved for life. Make them run and manage small businesses, so they learn about money and business quite early as most education these days are outdated. The smart ones will start using AI to acquire required knowledge as and when, and own businesses and services quite early instead of having to get employed after education.

You mention weightlifting. So then i guess i have to ask what you mean about survival skills. Because to me that's more about knowledge of different environments and the dangers to avoid in those.

Socializing and ability to be alone.

Some key survival skills for sure!
Rule #2: Double Tap

And of course....

Rule #3: Beware of Bathrooms

Jujitsu, or MMA in general.

Financial management is probably the best survival skill of all. Teach them to use money wisely.

weight training is good, means they take less crap from people and are more attractive to women

being real and speaking the truth is good too

Teach them to cook and get along well with people. These are the most important survival skills in modern society.

Hunting fishing knot tying camping …survival skills living off the land

Teach them to cook and clean.

Starting a fire....

[media=https://youtu.be/LUDEjulbqzk]

how not to get a gold digger

Lolz

[media=https://youtu.be/d_tfTdOGWuA]

[media=https://youtu.be/10qEOmZaYZg]

Ok