Off Season is the time to work on improving your form and efficiency. This simple drill from Mark Allen and LAVA magazine is perfect for improving your bike efficiency - making you faster on the bike AND faster on the run.
It's often called single leg pedaling or isolated leg training.
58-Second Series: The Best Bike Drill - LAVA Magazine
As Mark says in the video, be sure to be in the aero position while doing the drill. It is not easy at first, but with some practice you'll get the hang of it. Try to pedal smoothly - without the clanking caused by an uneven stroke. You'll know it when you get it.