Nordic poles are distinctly different from alpine poles and aren't interchangeable. They're significantly longer—often reaching your chin or higher—to maximize propulsion with each stride, whereas alpine poles only come up to your elbow area. This extra length is essential for generating power efficiently across flat or rolling terrain.
They're also much lighter, since you're lifting them thousands of times during a tour, and feature specialized grips and straps that wrap around your hand for better transfer of pushing force. Alpine pole straps simply aren't designed for this repetitive pushing motion.
If you're getting into classic cross-country or skate skiing, dedicated Nordic poles are a must. Using alpine poles will leave you working much harder for less forward motion, and they won't support proper technique. Nordic poles follow completely different sizing guidelines based on your height and specific discipline, so be sure to get fitted properly.