Be the kind of friend people would trust to spot their heaviest lift.

Spotting somebody means they can attempt what they would never risk alone, because they know you are paying attention. It has little to do with strength and everything to do with being reliably there at the one moment it counts. People hand you that job based on whether you are present and unbothered when things get heavy, not on how much you say. The same role exists everywhere: the person you would call when it is bad.

Be the one who answers. When a friend is about to try something difficult, ask when it is and check in afterward. That is most of it.