The first phase of BUD/S assesses SEAL candidates in physical conditioning, water competency, teamwork and mental tenacity.

Kroon later said that Courier's mental tenacity has become his most formidable weapon.

Its goal is to instill teamwork and cohesion, good working habits, physical and mental tenacity, confidence, military skills, and most obviously, discipline in recruits.

First Phase trains, develops, and assesses SEAL candidates in physical conditioning, water competency, teamwork, and mental tenacity.

Still, though Ms. Walker had great mental tenacity, her body had other ideas.

I think it's going to test their mental tenacity.

Even when you're playing badly, you have the mental tenacity to hang in there on those bad days and make cuts.

She has this mental tenacity.

I think the sport gives me a mental tenacity," he says, "the view that I will finish whatever I undertake because I don't drop out of my events.

His work habits kept him employed while his physical abilities caught up to his mental tenacity.