The Best Nike Shoes (and Gear) for Running an Ultramarathon

Nike Pegasus trail-running shoes, for example, offer a supportive and springy feel, excellent underfoot traction and a durable upper (the top half of the shoe). "All of these features are designed to withstand off-road running", Karnazes said.

"Shoes with these qualities are less likely to tear or break down when they run through brush, rub against rocks or get caught on thorns", he added.

"If the trail crosses streams, you may opt for a waterproof shoe or at least something that's moisture wicking", Karnazes said.

Running shoes made with Nike waterproof GORE-TEX technology keep feet dry so you can run further more comfortably. The invisible GORE-TEX fits along the upper, protecting the feet from precipitation without sacrificing that comfortable feel.

"On the other hand, road-running shoes require ample room in the forefoot, as feet tend to swell and expand when running ultramarathon distances", Karnazes said. When your shoes start squeezing your toes and heels, your muscles feel overwhelmed and it can make you struggle with balance. "That's why having some roominess in your shoes is convenient", Karnazes said.

Ultra-running shoes also need to be lightweight. Shoes made with Nike Flyknit technology feature high-strength fibres that create lightweight uppers with targeted areas of support, stretch and breathability. The Nike Innovation team has also developed a new Flyknit upper called AtomKnit, which builds on the Flyknit technology and delivers an even lighter feel with minimal water absorption from rain and sweat, enhancing breathability.

During especially long runs, it's imperative to carry more than just water. A running gilet is a functional solution to stash water, electrolyte gels and other essentials.

"A couple of ultra sayings come to mind about backpacks: light is right. The opposing viewpoint: go light, freeze at night. Experiment and find what works best for you", Karnazes said. That said, the conditions of the race—the weather, distance, time and terrain—and the subsequent gear you might need will help you narrow down your options.

(Related: Should You Run in a Weighted Vest? Experts Explain the Benefits—and Drawbacks)

Nike hydration running gilets are form-fitting, lightweight and designed to carry all the essentials. With elements like adjustable chest and side straps, trekking-pole holders, built-in whistles, and multiple front and rear pockets, these gilets offer something for every runner—and every distance.

Weight and layering are key when running high-mileage distances where the weather and terrain are unpredictable. Lightweight sweat and water-wicking tops and shorts are essential. As for extra layers, Karnazes recommended carrying a lightweight running jacket, or tying one around your waist.

"The weight is minimal and the warmth that can be provided is worth it", he said.

Nike has several lightweight running jackets, and many are made primarily of polyester, meaning they're both water-repellent and lightweight. The reflective design details on these jackets also help to boost visibility, a major perk when running in the dark.

You might also want to consider packing a pair of tights or leggings for additional warmth. "The compression is welcomed after multiple hours of running", Karnazes said. For context, studies have indicated an association between wearing compression garments and enhanced blood flow. However, research around this is a bit conflicting.

Designs made with Nike Dri-FIT Technology are lightweight and engineered to move sweat away from the skin for quicker evaporation, helping you stay dry and comfortable.