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End of an era marks a new chapter for Ninja Warrior Arnold Hernandez

As a new Ninja gym opens near LA, Arnold will leave behind his treasured backyard course.

Tyler Golden/NBC

In August of 2016, we told you about the “secret” Ninja Warrior training course in Los Angeles. With a lack of Ninja Warrior focused gyms in the Los Angeles area, competitors had turned to an ever-expanding, homemade course in the backyard of Arnold Hernandez.

Arnold, a competitor on both American Ninja Warrior and Team Ninja Warrior, started his training in the most heart-wrenching way. When his mother passed away in October of 2013, Arnold was a young man in need of something to take his mind off his pain. He stepped into the backyard of the home he shares with his father and built one Salmon Ladder.

That Salmon Ladder turned into full blown course. That course brought Arnold a business, hosting classes and birthday parties. His 323 Training Grounds became the place competitors trained before the Los Angeles trials of American Ninja Warrior. Matt Iseman and Akbar Gbajabiamila have both attempted the obstacles there.

And now, the course is coming to a close. But that’s only because it brought Arnold one more thing: A new career.

Arnold was approached by Chris and Brian Wilczewski to head up the newest Movement Lab location. Along with fellow athlete Scott Willson, they opened the first official Ninja Warrior focused gym in the Los Angeles Area.

After a year of location hunting and hard work, Arnold proudly looked around his new gym in San Dimas on the morning of December 2, when the doors were first opened for a soft trial. We stopped by to take a look at the new location and catch up with Arnold about the emotional journey he’s travelled.

“It's pretty surreal to me. It all started with my mom passing away and that's the reason I started building my backyard course. And the fact that it evolved to me actually having my own gym... I don't know. I can't really find the words to explain it. It's just so weird to me. The fact that I have my own gym. It's surreal. I still feel like it's my backyard.”

Thank you to everyone that came out for our soft open! We hope to see everyone back Wed for class!

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“To me, it still feels like I'm in my backyard. Just as nicer facility. Everything is more legit. When I used to build things in my backyard, I would be on my own budget. I'd go to Home Depot and be like, ‘What's the cheapest way I could build an obstacle?’ But now that we have a huge budget compared to what I used to have, when I go to Home Depot I'm like, ‘Oh my God. I can buy so many things! I can get whatever I want!’ So now I get to think, ‘What's the best way to build an obstacle?’ Rather than the cheapest.”

Although Arnold is overcome with excitement over the new gym, the fact that an era is coming to a close is not lost on him. His backyard course will be coming down.

“As of now, actually I have my last birthday party booked tomorrow. So that's going to be the last thing I do. Even in the past month I haven't been able to do maintenance on my backyard course. So when I get home today, I'm going to have to do a bunch of clean up to get it ready for tomorrow's birthday party.

But pretty much after tomorrow, it's not going to be used.

It is bittersweet. It kind of sucks. So many memories came from that backyard. All my friends. But my dad, he wants me to take it down. And I'm not going to use it, so I might as well take it down. But it's going to stay up for I don't know how long before I have time to actually start demolishing it. I don't know when that's going to officially happen.”

“I'm guessing once things get settled here and I have more time, little bits by bits I'm going to start taking it down. I'm going to invite a bunch of friends who used to train that are all going to be willing to help me to start tearing it down. We were saying we should take the scrap pieces and do a bonfire somewhere.

I'm not really using it anymore, but I don't really want to start taking it down because it's going to be bittersweet. I'm going to try to hold off as long as I can.”

When asked what’s been most rewarding about the long process of opening a new business, Arnold is quick to give credit to the community around him.

“Just seeing it come together. Today is December 2nd. We started building November 2nd, so exactly one month ago, this was an empty warehouse. The fact that in one month, we managed to get all this... I think that's the most rewarding. The very first structure we built was that box in the corner over there, for the trampoline. I remember the first day, we were so proud of that first structure.”

What wall will you try first? Remember to register for our soft opening Dec 2nd!

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“It didn't look like a gym at first. There were pieces of scrap wood all over the place. It was a mess. It didn't look like a gym. Luckily we had so much help from my friends, my 323 Ninja Training community. A bunch of them came out. Some of them stayed all day with us. If it wasn't for them we wouldn't have been able to do this. We had a bunch of help.

The most rewarding thing is the time that we did it in, and just seeing it come together.”

The facility, located in San Dimas, CA, is the third Movement Lab gym. Also known as MLab, the concept was one of the very first Ninja Warrior gyms in the country, led by Chris and Brian Wilczewski, both long time American Ninja Warrior competitors.

The new San Dimas location has around seven thousand square feet of space. While new obstacles are still being installed, the gym already features a parkour area, trampoline with foam pit, spring floor and a truss system that allows for many American Ninja Warrior style obstacles. There’s also the essentials, like the Salmon Ladder and three Warped Walls at 10, 12 and 14.6 feet in height.

MLab locations (Ohio, New Jersey, and now California) feature a well-established training curriculum that focuses on strength and skills through classes. Chris Wilczewski shared, “If you're serious about the show, or you have kids that are serious about it, this is the place to come train to get better.”

A regular class schedule will be in place starting Wednesday, December 6. You can learn more about MLab LA, including schedule and pricing information. here.


Arnold was eager to give credit to those that helped him turn this dream into a reality. In Arnold’s words, “without them we wouldn’t have been able to finish before our soft opening.”

  • Scott Willson
  • Dominic Torres
  • Eric Gates & Breanna Schear
  • Tim Dexter
  • J.R. Dira
  • Aaron Calderon and Diego Bressant
  • Tiana Webberley
  • Derek Miyamoto