About SISU Endurance
SISU Endurance exists because too many endurance events try to be everything to everyone.
We don’t.
SISU is a Finnish word that roughly translates to grit, resilience, and quiet determination. It’s the ability to keep going when things get uncomfortable, uncertain, or hard. That idea sits at the center of everything we build.
We create events for people who want to challenge themselves, not chase perfection. Physically, mentally, and sometimes spiritually. The kind of challenge that leaves you tired, proud, and changed in small but meaningful ways.
No cookie-cutter formats. No conveyor belt races. No corporate nonsense.
What We’re Really About
SISU events are built around adventure, not optimization.
You’ll find:
- Experiences designed to reward grit, curiosity, and effort
- A welcoming environment where beginners and veterans share space
- Events that feel human, because they’re run by humans who care
People remember our events because we remember them. Names matter. Effort matters. Attitude matters.
The community, the camaraderie, and the shared experience are the point. The miles are just the vehicle.
Who SISU Is For
SISU is for anyone who wants to explore, adventure, and test themselves.
That includes:
- First-timers who want something different
- Seasoned endurance athletes who are burned out on rigid formats
- Parents, weirdos, grinders, and people figuring things out as they go
If you show up curious, respectful, and willing to try hard, you belong here.
Who it’s not for:
- People who need everything to be perfect
- Chronic complainers
- Bullies, bad actors, and anyone who shows up to make things worse for others
We protect the vibe on purpose.
The SISU Spirit
We reward:
- A sense of adventure
- Grit and determination
- Being a good human when it’s hard
We don’t reward:
- Entitlement
- Bad attitudes
- Tearing others down
The SISU spirit is simple. Show up. Try hard. Be decent. Support the people around you.
What It Feels Like
People tell us they love our events because they feel different.
They feel:
- Welcoming instead of intimidating
- Challenging without being extractive
- Personal instead of corporate
At camp, you’ll see people cheering for strangers, sharing food, swapping stories, and grinding through the night together. At 2 a.m., it’s quiet, honest, and real. That’s where the good stuff lives.
Who’s Behind It
SISU Endurance is run by Daren de Heras in California and Tony Matesi in the PNW.
We’re not outsiders designing experiences from a spreadsheet. We’re endurance athletes who’ve done the hard stuff. Death Races, long nights, ugly miles, and the kind of events that change how you see yourself.
We direct events because we love bringing people together and watching them surprise themselves.
Our goal isn’t to squeeze participants for profit or treat them like numbers. It’s to create experiences that feel challenging, rewarding, and worth looking forward to all year.
We care about the details. We care about the people. We care about doing this the right way.
Why We Exist
SISU Endurance exists to create events that matter.
Not because they’re perfect. Not because they’re flashy. But because they’re honest, challenging, and rooted in community.
If you’re looking for an experience that pushes you, welcomes you, and leaves you better than you found it, you’re in the right place.
Show up. Try hard. Be decent.