(article title reflects signs of a not-nearly-misspent-enough youth)

There is no free lunch from glide or gravity. The only thing that can move me forward faster is doing more work per minute with some muscle.

Some bodily motions may feel like I'm getting something for free by "falling" or "pendulum" to the other side, or by "extending the glide".

Physics says that it's true that some of these motions can increase the amount of force in a particular phase of the stroke-cycle. But they can do that only by robbing power from some other phase or by wasting time and slowing down some other phase.

Don't get fooled by the easy promises: feeling the "glide" or the "fall" can be fun but it really helps only comes together with the muscular work of a "push" or a "lift" though that muscular work might come at different time than the "free lunch" feeling. Better to learn which of your muscles can really help you go in clever unexpected ways.

Tricky "Secrets" of Ski Skating, Ken Roberts

OK, so it's actually about XC skiing. But, you know, the physics is pretty similar.