Photograph by John B. Carnett

“I don’t think I’ll make it 16 miles,” I tell Loren Myhre, senior researcher at Nike’s Sports Research Lab, as we enter a 20- by 20-foot environmental chamber on the company’s Beaverton, Oregon, campus. I’m holding a wad of wires connected to sensors glued to my chest, abdomen, rib, left deltoid, scapula, and lower back. They’ll measure my skin temperature over the next two days as I wear-test Nike’s latest apparel innovation, Sphere.

Sphere’s concept is simple: Small circular indents in the fabric hold it away from the athlete’s body, creating an airspace (or “personal atmosphere” in Nike-speak) that-depending on the fabric -cools, warms, dries, or protects from the elements. The tech was bred from the company’s 2000 Olympics dimpled tank top, which was worn by elite runners. Can the technology help lesser athletes like me, a wanna-be marathoner who runs a 10K every other weekend?

I choose Sphere Thermal (the others are Dry, Cool, and Pro) for my tests. It’s designed to prevent post-run chills in hot weather and hold warm air close in the cold. Over two days, I make four 50-minute treadmill runs, two each in 35