Instructors must know the muscles involved in cycling to engage the musculature appropriately and adequately during the group cycling program. Consideration must also be given to the fast- and slow-twitch muscle fibers that comprise the cycling muscles.
Pedaling dynamics.The actual biomechanics of pedaling is so intricate that its precise implementation will distract and confuse even the most avid cyclists. Also, the exact triggering of each leg muscle as it extends, rotates or abducts happens so quickly within the pedal rotation that physical awareness of most muscle implementation is difficult. However, the breakdown ofmuscle triggering and recruitment can be simplified.
Think of the cycle crank asthe face of a clock. Now consider the effective range of the following muscle groups and how they apply to the hours of this clock.
1.Quadriceps — Rectus femoralis (11:00 to 3:00);Vastus medialis (4:00 to 10:00);Vastus intermedius;Vastus lateralis
2.Calves — Soleus (5:00 to 1:00);Gastrocnemius (9:00 to 2:00)
3.Anterior shin — Tibalis anterior (6:00 to 11:00)
4.Hamstrings –Biceps femoris (7:00 to 2:00);Semitendinosus;Semimembranosus
5.Gluteus –(11:00 to 4:00)
What riders should feel.Strength and endurance are only part of the cycling story. The real key to cycling is efficiency. Therefore, it is imperative that all instructors engage the participants to “feel” each degree of the pedal stroke periodically throughout the class. To use a term from sports psychology, have them “be the bike.”
Rather than paying attention to the particular muscle groups thataid in crank rotation, pay attention to what is actually felt while indoor cycling. Since indoor cycles are direct drive (with a few exceptions) and use a flywheel, what is feltduring indoor cyclingis somewhat different than what is felt while “true cycling.”
This can be simplified with the following:
1. Downward arc uses the”quads” (power rotation).
2.The toe dragsalong the bottom with the”calves” (transition between efficient working angles).
3.The upward arc uses the “hams” (off power rotation).
4.The leg glides over the top by releasing all previously used muscle groups and engaging the “gluteus” to start over(commute to power).
The recruitment of muscle groups in pedal rotation can be broken into parts, but the actual assignment of muscle groups in rotation of the crank does not have segments that should be felt individually.The initiation of muscle use merges with active muscles, and then usefades away. Also,beginning cycling students and/or students working at lower resistance and RPM levels won’t feel gluteus recruitment. To feel this recruitment, resistance must be higher than moderate.
