4 Days, -50 Degrees, and One Rule: Keep the Tank Full

John Phelps spends his days managing hut systems for San Juan Huts in Ridgeway, Colorado, one of the premier bikepacking guide operations in the country. So when his coworkers started talking him into longer and longer rides, it was probably inevitable that things would eventually get out of hand.

He laughs about it now, "You start with like a 20-mile ride," he says. "And then you're doing 100, 200-mile rides, and things get kind of carried away."

Carried away is one way to put it. This past February, John lined up for his second Iditarod Trail Invitational 350 (ITI), a self-supported fat bike race across 350 miles of Alaskan wilderness, from Knik Lake to the interior village of McGrath. No GPS tracks provided. No crew. Two drop bag checkpoints. Whatever you need, you have to carry.

The Worst of Both Worlds

The 2025 ITI was, by most accounts, an absolute brutal year. Conditions that normally arrive one at a time showed up together: heavy snow in the interior and temperatures that bottomed out around -50 to -60 degrees.

"Usually you get one or the other," John says. "This year you got the mix of everything."

He'd done the 350 once before, two years earlier, and that experience gave him a baseline of calm that proved critical. But nothing fully prepares you for what happened at Bear Creek Cabin.

After pushing through nearly three days without meaningful sleep, John and his riding partner decided to stop at a remote safety cabin (Bear Creek) between Rohn and Nikolai. The plan was a few hours of rest. The reality was a cabin sitting at -20 to -30 degrees inside.

"I crawled into my sleeping bag and after 20 or 30 minutes I was shivering," he says. "There was this brief moment of panic - how much longer can my body just keep going before it shuts down?"

The answer became very clear to John and that was to get back on the bike. With Nikolai still roughly 50 miles out, John pulled himself out of the bag, got moving, and kept going. "You high-five yourself internally and just tell yourself you can get to Nikolai. That's all you're focused on."

Keeping the Gas Tank Full

On multi-day winter ultras, nutrition isn't a luxury but becomes a survival requirement. Most athletes target somewhere around 300 calories per hour just to sustain forward movement. In extreme cold, eating anything solid becomes its own challenge. Food freezes. Appetite disappears. Stopping long enough to cook is time and warmth you can't afford to lose.

John's approach has always been practical over precise: pack more than you think you need, make sure it's consumable even when frozen, and stay ahead of the bonk rather than chasing it.

It was at the Fat Pursuit in Idaho, a qualifier for the ITI, that he first came across RecPak in a race goodie bag. He didn't use it that day, but when he got home and looked closer, something clicked.

"700 calories and I can pour water in it and be done in less than a minute," he says. "It felt almost like cheating."

For the ITI, he mailed (Rec)packs to his drop bag locations and carried more from the start. At each checkpoint before a major push, he mixed one up and drank it before heading back out.

"I looked around and thought, I've got a 700-calorie jump start over most people. And it wasn't just calories but also the vitamins and minerals, I was like, this is far above your standard powdered calories."

The result? He never bonked. Not once across four days and two hours of racing in some of the harshest conditions the ITI has produced in recent memory.

"It was almost like keeping my gas tank full versus running on the latter part. I never felt like I needed that extra boost because I never fell behind."

He finished with all his fingers, all his toes, and a quiet understanding of what his body can actually do when you give it what it needs.