I prescribe isolated leg training intervals (ILTs) for nearly of my clients. I often get comments and feedback. I wanted to take a moment to share some FAQ's about this workout.
In my experience, ILTs are by far the most important workout for new and intermediate cyclists. After 20 years of riding and racing, I still incorporate them into my own training routine. ILTs are short intervals pedaling with only one leg. Why are they so important and beneficial?
Not all legs are equal. We all have some amount of strength imbalance. We have a dominant side. We also may not be symmetrical. Bone length, muscle size and strength, and hip alignment contribute to variations in strength. By pedaling with only one leg, you expose the differences between each. You can focus to improve the weaker side. For those with a severe imbalance, I recommend doing more intervals on the weaker side to correct the imbalance faster.
Build strength, recruit muscles. ILTs are similar to a one-legged squat. When doing a squat, you are building strength. With only one leg, other smaller muscles are forced into action in order to maintain balance. In pedaling a bike, the gluteal muscles and quadriceps do the majority of the work pushing the pedals down. When pedaling with only one leg, other muscles are forced into action. The calves and knee flexors pull the crank back at the bottom of the stroke. The hamstrings pull up. The hip flexors push the cranks forward at the top. See the attached muscle use chart.
This is the time to remember. The early-season is the time to incorporate these intervals. Build strength, recruit muscles. Correct imbalances and poor form. Then we can move on to more advanced workouts to maximize the gains made.
Pedal in circles...Not squares. Untrained cyclists tend to have a choppy pedal stroke, pushing too hard for only a portion of the stroke. They often appear to fight the bike, rocking body and bike as the cranks turn. ILTs improve your pedaling technique. You apply force more evenly throughout the pedal stroke with both legs. More muscles are involved. When you get it right you feel a certain unity between bike and body. You may be putting in a big effort but the upper body remains still and relaxed while the bike continues straight with little effort required for balance.
Use the element of surprise. When significant power is not required, we can ride without concern for form and technique. When it is time for a big effort, use good form to disguise your effort. Maintain the same appearance or body language while you fire up all of those extra recruited muscles. As the gap between you and your competition opens, leave them wondering how you sped away without any sign of extra effort.
I hope this provides a better understanding of why these intervals are so important. I will come back and explain how they are to be done effectively in a second message.