We know it is safe to keep both feet attached to the pedals and simply focus on one leg at a time, but is it safe, and should we unclip one foot to perform pedal stroke drills in our indoor cycling classes?
To stay on point I’m not going to discuss if and why 1-legged drills are effective, but rather limitations or concerns that should be considered when attempting them in our indoor cycling classes.
First, do outdoor cyclists perform 1-legged drills? Yes we do. They have been part of our training program, usually during the base training months (Dec-Mar) for as long as I can remember. Over the last 20 years I have spent countless hours in my basement riding my road bike on an indoor trainer. A considerable amount of time each week was devoted to 1-legged pedal drills with a goal of creating a smooth pedal stroke. So why wouldn’t we want to use this same training technique during an indoor cycling class?
1-legged drills can present a safety risk during an indoor cycling class for 2 reasons: (1) most indoor bikes use a fixed weighted flywheel and (2) it is difficult to maintain cycling form and proper biomechaincs.
As we know, the weighted flywheel on the indoor bike simulates the effects of inertia and momentum experienced when riding a real bike outdoors. Since the flywheel is “fixed” (the pedals can turn the wheel in both directions), it can apply forward pressure on the legs and joints once it picks up speed. When a rider pedals with both legs, often the weaker muscles of one leg (hamstrings and hip flexors) are counter-balanced by the stronger muscles of the other leg (glutes and quads) creating a smoother rotation. I’ve seen riders struggle in classes to maintain a smooth pedal stroke with both legs — remove 1 leg from the equation and their pedal stroke becomes very choppy. This happens because the weaker muscles cannot generate the same about of force as the stronger ones (flexors vs. extensors). However, due to the momentum created by the weighed flywheel, the pedals keep turning even though there is little to no force contribution for practically half the pedal stroke. In reality, half of the pedal stroke is not under the rider’s control. This can place a tremendous amount of force on not only the joints of the legs (hips, knees and ankles), but stress other stabilizing joints and muscles such as the back, shoulders and neck. 1-Legged drills are best performed on bikes that coast because the rider is forced to activate the muscles throughout the entire pedal stroke. As a result, it is usually VERY obvious which muscles are not contributing properly because the rider will experience “dead-air” and awkwardness often at the bottom and top of the stroke.
The other problem is “where do you put the leg that is not clipped in?” Back in the day....it was common for cyclists to have 2 milk crates. Maybe you’ve seen those plastic bins at the grocery store which hold four 1-gallon jugs of milk. As a kid growing up in Brooklyn NY, I remember the “milkman” placing one of these crates full of milk on the front steps of our house. Anyway, cyclists will place 1 crate on each side of their bike (locked into the indoor trainer) as close to the moving pedal as possible. To focus on one leg, we’d simply unclip and rest our foot on the crate. It was a perfect height to enable us to maintain our form and balance (BTW, 2 chairs will also work nicely). Unless everyone in your indoor class comes prepared with their own milk crates, riders are usually forced to do a number of things with their foot in order to pedal with one leg. They can try to dangle it in the air, prop it up on the center of the bike frame, reach way back and rest it on the back legs of the bike or even lift it up on top of the handlebars. I’ve tried them all but was not able to get my foot on the handlebars (stink'in hamstrings). Regardless of which leg position you can achieve, your pedal mechanics will be affected and you will place your joints and muscles at risk with little to no benefit. A number of years ago, an unstable rider was attempting to perform 1-legged drills with his leg suspended next to the bike. His foot wandered too close to the whirling pedal and he chipped his ankle bone (medial malleolus). The instructor of the class was overwhelmed with seemingly endless paperwork and scrutiny.
So from a health and fitness risk stratification standpoint, 1-legged drills (with one leg unclipped) should not be performed in an indoor class unless both the bikes have the ability to coast and riders are either wearing diamond-plate steel anklets or until clubs start equipping cycling studios with milk crates.
Originally posted 2011-08-05 11:30:24.