The type of pedals you use can help you pedal more effectively, and there are different types more suited to different biking activities. Commonly used by long-distance or road racers are clipless pedals. These pedals require riders to snap in, or clip in, their shoes before use.
Riders wear lightweight, flexible cycling shoes. On the bottom of these are two mounted cleats, which attach securely into enclosures on the clipless pedal, keeping you locked into the bike. This probably sounds familiar to skiers, as it's similar to the concept of boots and ski bindings; modern-day clipless pedals are a direct outgrowth of the ski binding technology and concept.
One major advantage of the clipless pedal system is that it allows for float -- the shoes are slightly loose, allowing for side-to-side foot movement, toe movement and ankle rotation, which are all important for utilizing the full-stroke technique. These pedals are also lightweight, which helps your bike be more aerodynamic and energy efficient. More importantly, because you don't have to press your foot down with your own weight to keep the foot in place on the pedal all the time, energy efficiency increases. Then, that energy is used in the back end of the upward stroke. Because energy flows from the beginning of the stroke to the end, the result is a pedaling technique that distributes energy evenly and consistently from start to finish.
Your movement may feel restricted at first because you're locked in, and it's more up to you to keep the bike balanced. Clipless pedals aren't the best idea for mountain biking -- bikers have to walk over difficult terrain occasionally, and it's hard to detach yourself from your bike and walk with metal brackets on the bottoms of your shoes. But practice makes perfect, so try clipping in and out of the pedals while you're against a wall to practice balancing. Next, try them out on soft ground or grass for a softer landing in case you fall. If you've never used clipless pedals before, you'll notice right away the more forceful way that the bike pulls your foot upward. It's as if you're part of the bike's mechanics. Once all this is familiar, it's time to test out the full-stroke motion.
If clipless pedals have clips, then what are clipped pedals like?