Improving Muscle Function and Cycling Power

From an article in the June 2010 edition of Triathlete magazine.  The article was written by Nathan Koch, PT and Wolfgang Oswald PT.

“Have you ever wondered why getting lower in the aero cycling position makes you lose power, or why you run poorly or experience calf and quad cramping off the bike, even with appropriate brick training?”

 

Reason #1: Knees get closer to the chest.
The quest to get aero results in the knees getting to close to the chest, which over-stretches the gluteus maximus and knee angle, which in turn lengthens the quadriceps.  This might also lead to excessively fatigue to the gluteals for the run and cause slower run times or cramping.

Solutions:
Shorten the crank arms.  This reduces the hip and knee angle at the top of the pedal stroke and reduce the lengthening of the glutes and quadriceps, allowing for more power and less fatigue.

Using ovalized chainrings.  These expensive rings are oval, thus changing the power curve required to push through the pedal stroke.  An example would be if you are using a 53t ring, at the top of the pedal stroke, where the least amount of power is generated, the oval rings give the feel of a 49t ring, thus easier to push.  During the pedal stroke where maximum power is generated, the rings give the feel of a 56t ring, thus more power.

Reason #2:  Muscle reflexive inhibition. 

“Each muscle group has its opposing muscle groups, as the quadriceps are opposed by the hamstrings.  If one of these muscles is tight and is stretched to the point of tightness, it inhibits the opposite muscle from producing maximal contraction”

The lower the cyclists gets in the aero position, the more hamstring length is required to generate maximum power.  Thus if the hamstrings are tight, the quadriceps will experience reflexive inhibition.

Solutions:
Stretching can be used to improve power production by reducing inhibition of the major cycling muscles.  Static and dynamic stretching of the hamstrings, quads, hip flexors and gluteals is recommended.  Do these stretches for 30-60 minutes, but only post workout as static stretching can reduce the muscles contractile force by 30%.

Reason #3: Lever Forces
”In the power phase of the pedal stroke, when gluteal complex and quadriceps are producing significant amounts of force, it’s the calf that is stabilizing the ankle to allow those forces to be driven through the crank and into the drivetrain of the bike.  Excessive loss of ankle stability, or too much ankle movement, will cause a loss of power transfer into the pedals”

Solutions:
Moving the cleat all the way back.  Moving it to somewhere between midfoot and the first toe joint may be enough to increase power output and reduce calf fatigue or cramping.  Saddle height and/or fore/aft position may also help, but the author recommends you work with a professional bike fitter for those adjustments.