"skimo" means racing. Using "skimo" to mean ski mountaineering—or vice versa—flags the speaker as either: a non-English speaker, which is fine; or a beginner, which might not be what they’re going for.
The serious athlete is neglected. A simple guide to "How to Run Your First 5K!" will always outsell an essential-but-dense tome like *The Lore of Running*. But training to survive short-term participation does little to maximize long-term performance.