Using your indoor trainer will not only benefit your cardiovascular fitness but you can also incorporate specific drills dedicated to improving your technique. Often this is overlooked in favor of sessions that promise the untold virtues of more power and speed but, when it comes to being a better overall cyclist, your technique is just as important to ensure you have a smooth and efficient pedalling stroke.
Try pedaling with alternate legs individually for one minute on each side and you’ll soon see if you favor one leg over the other on your push stroke. You may also be surprised at how difficult this actually is. By comparing your speed on each side, or by using a power meter like the Garmin Vector which monitors left and right power output, you can work specifically on any imbalances that you may have. Regular one legged drills will certainly help to improve your overall pedal stroke and can really give the sense of pedalling in circles when you return to using both legs. Aim to keep your upper body still and really focus on using your single leg to pedal. Doing this on the rollers can really help your core stability too.