Initial Navy SEAL training is a 24-week gauntlet of insane physical feats, extreme discomfort, and terrifying surprises all topped off with a final and apparently aptly named Hell Week. No wonder something like 75 percent of candidates drop out

Which means that those who do manage to make it through are truly the toughest of the tough. What sets them apart from those of us who would run screaming from even a shadow of this test? And can their secrets help us mere mortals have more grit in the face of more everyday challenges (or even less everyday ones, like a pandemic)? 

Sean Kernan is well positioned to answer these questions. A freelance writer rather than a warrior himself, he still had a front-row seat growing up to exceptional endurance. His dad was a Navy SEAL. On Medium recently, Kernan shared the lessons he learned from his father, including one simple tip that anyone can use to increase their endurance. 

How to survive your own personal Hell Week 

Kernan shares plenty of military wisdom you've probably heard before -- things like "get up early" and "make your bed" -- but perhaps the most useful lesson his father taught him was how to keep yourself going when you hit what feels like rock bottom.

It's a lesson Kernan's father learned himself during SEAL training's notorious Hell Week. "Hell Week is ridiculous. You wake up on a Sunday to gunfire. You then work out until Friday with no sleep. Hell Week is the bottleneck that breaks a lot of talented people," Kernan explains. 

His father made it through, but he told his son that he had his moments of doubt. The worst of them hit on Tuesday morning. Why Tuesday morning? When Kernan's dad explained it, the timing made total sense. 

Hell Week kicks off at 2 a.m. on Sunday and continues all day Monday and through Monday night without let up. "You run around getting yelled at. You are doing pushups, carrying logs, rolling in the sand. This continues all day, then into the night. As people are sleeping in their warm beds, you continue exercising, shivering, and getting shouted at," Kernan writes. 

Just reading that sounds hellishly exhausting, so imagine how tired those who actually live through it must feel come sun up on Tuesday. And yet there is still so much to go. That's when guys start thinking things like, "It's only Tuesday. How am I going to get through all of this?" and "If I'm this tired already, and I'm not even halfway through...." 

"The people that start thinking like this are the ones that quit," Kernan reports. Those who make it through "only look a few minutes in front of them. They don't worry about Thursday or Friday. They are only focused on each individual exercise. They get through it one thing at a time."

Sometimes tunnel vision is a good thing. 

You're unlikely to have to heave massive logs into freezing surf for days on end, but Kernan insists that the same technique can help you get through lesser trials too. When it comes to extreme endurance, the lesson from SEAL training is simple: Tunnel vision is a good thing. 

"You can apply this to many aspects of your life. If you are studying for a massive test, take it one page at a time. Working on a huge presentation, one slide at a time," he writes. "Lower your vision and piecemeal those big hurdles. It reduces the perceived mental weight of the tasks." Ultramarathoners who run insane distances swear by the same intense focus on the now. 

So next time getting through a challenge seems like it might be too much for you, lower your gaze to whatever next step is right in front of you. There are times in life where big-picture thinking pays. Those moments when you doubt you have the strength to put one foot in front of the other aren't among them.