Like swimming and running, cycling efficiently is all about force application and reducing wasted energy.
Most people when they ride just push down across the front part of their pedal stroke using their quads. They don’t add their glutes into that force application nor do they pull back with their hamstrings or up across the back part of the pedal stroke with their hips. By using more muscles in the pedal stroke you are able to take the pressure off your quads to provide all the power to drive you forward. You’re legs will therefore last longer and over time you’ll be able to train yourself to ride farther and faster.
Keep in mind though that there’s a process called angiogenesis happening in your body whereby over time you will adapt to your training to develop more capillary pathways and mitochondria in your newly used muscles which will help you to provide oxygen and energy to your muscles.
I often do the majority of my cycling training using Powercranks. They are hard to use, frustrating and very good at getting you to pedal efficiently. When I refer to efficient pedaling I’m talking about your ability to pull up with your back leg at least enough to unweight the rear leg across the back part of the cycle stroke. When I first started using the powercranks I thought I was a good cyclist. However, my first time using the powercranks I couldn’t ride for longer than 30”. My hip flexors were so fatigued from riding that I had to stop. You don’t need to get a pair of powercranks to ride properly, they just stop you from riding improperly. You can start to get the same effect though by doing a lot of single leg riding in order to isolate and focus the effort on certain muscles in your legs.
What I had to do to be able to ride for hours with the powercranks (ie ride more efficiently) is develop the strength and endurance of my hips flexors. Doing so improves your ability to pull your leg up across the back part of the pedal stroke and keep perfect timing with the downstroke leg. Doing so prevents the rear leg from weighing down the forward (downstroke) leg which in effect sucks power out of the downstroke, instead of allowing that power to go into driving the bike forward.
Doing this initially though is very hard. So much so that I had to decrease my cycling cadence into the low 70s in order to be able to ride for any appreciable length of time. Riding for longer periods with good timing is important as it better allows your musculature to develop good muscle patterning and adaptive changes (angio-genesis).
Once your ability to ride smoothly and with good timing (pulling the rear leg up in time with the forward downstroking leg) then you can gradually increase your cadence.
You will find it easier to do this if you sit up as tall as possible on your bike (i.e., not in the aero position) in order to open up your hip angle as much as possible. Having an open hip angle will allow you to better activate the hip flexors.
As you develop the ability to ride with increasingly higher and higher cadences for longer and longer then you can (for triathletes) begin to get more and more into the aero position. Doing so too quickly though will shut your hip flexors down and reduce the efficiency of your cycle stroke.
It is very easy to ride with the focus on your quads. However, you should be learning to activate the glute (butt) muscles in order to bring in top power to your cycling stroke. It’s hard to explain how to activate them. You can try by lying on the floor on your back and squeezing your butt repeatedly. Best way after that though is to get on your bike and ride. Feel like you’re pulling the lower inner portion of your butt inwards towards the seat of your bike. It will feel tough at first but should give you lots of power once you get accustomed to it.
Across the bottom part of the cycle stroke you should feel like you are pulling your foot out of the back of your cycling shoe. Don’t get fancy, just pull back using your hamstrings.
Pulling it all Together
As you ride your bike you should feel that your power output is smooth and consistent. You don’t want to feel your bike pulsing forward, driven only by your downstroke. Keep a smooth power output throughout the whole range of your pedal stroke and you will ride smoother, longer and faster.
Anyway, just some thoughts on riding a bit more efficiently. Let me know if you have any questions.