Chris Cassidy had his physical and mental toughness challenged regularly during his ascent in the Navy SEALs—experience that proved useful when he became an astronaut for NASA, most recently spending 196 days in orbit commanding the International Space Station (ISS) during Expedition 63. Not one to shy from a challenge, here’s how Cassidy stays tenacious. – As told to Charles Thorp

One for All

The selection process with the Navy SEALs is extremely arduous. The relationship you have with physical fitness is a hateful one. From the moment you get up to the time you wrap up for the day, there’s punishment. You learn quickly you won’t accomplish anything without help from your fellow soldiers. I’ve accomplished a few incredible things in my life, but being named The Honor Man of my class at BUD/S is the one I’m most proud of, because it’s voted on by your peers, who are all extremely motivated people. The value I put in teamwork has only gotten stronger since.

Prepare for Anything

During my time with the Navy SEALs, my team was deployed to investigate caves in a mountainous region between Afghanistan and Pakistan. What was going to be a 5-mile patrol downhill turned into a 10-mile trek with 55-pound
packs because the helicopter couldn’t land. Then headquarters decided they were going to have us stay another nine days. Experiences like that taught me there’s only so much you can control, and you won’t accomplish anything without help from fellow soldiers. It’s important to be prepared for the unknown.

Build Mass

We work with NASA’s Astronaut Strength, Conditioning and Rehabilitation group coaches for six months leading up to our launch dates, and they also design workout protocols for our time in orbit. [Cassidy’s 2020 stay aboard the International Space Station lasted 196 days.] If we didn’t work out, we’d return with severe bone-density decay. For that reason, the majority of our training is based around legs and core, and we train for two hours every day. There’s a stationary bike, treadmill and weight machine right by the cupola window that looks down on Earth 250 miles below. I have a Peloton bike at home, but nothing competes with that view.