Because you're not built like a robot with perfect symmetry, you may develop muscular imbalances in your legs when performing a repetitive activity such as cycling. For example, many cyclists tend to overdevelop their quads and fail to condition their glutes and hamstrings at the same level. Different types of imbalances in cycling leg strength can create inefficient movements, destabilize your joints and raise the risk of injury.
Front Versus Rear
The pedaling movement puts more stress on the fronts of your thighs than the backs, which can lead to powerful quads and lesser developed hamstrings and glutes. If your quads overpower your hamstrings, they’ll drag your hips forward and down. Your hamstrings are unable to counteract that tug, resulting in compromised posture and weakened core muscles. You’ll tire more quickly on the bike as well as face an increased risk of back strain and injury. Correct the imbalance by building your glutes and hamstrings with straight-leg deadlifts and leg curls and reducing the isolation exercises you do for your quads. Also perform squats and leg presses, which equally strengthen all of your leg muscles.
Right Versus Left
Because you have a dominant leg, you’ll tend to apply more pedaling power on one side than the other. By increasing the pedaling strength of your nondominant leg, you can correct this imbalance, achieve a more efficient stroke, and prevent injury. Perform single-leg drills on a stationary cycle in which you pedal with only one foot in 20- to 30-second intervals. If you do these drills on a regular bike, you risk crashing due to the imbalance created by the exercise. Aim to complete several reps of a single-leg drill before and after a cycling session. Gradually increase the duration of the interval to one minute. As you boost your ability to apply power equally with both legs, you can eliminate dead spots at the peak and bottom of your stroke.
Inner Versus Outer
In Brian Halpern's book "The Knee Crisis Handbook," a seasoned amateur cyclist complained of patellofemoral pain, or pain in the front of and around his kneecap. The pain stemmed from an imbalance in the strength of his inner thighs in comparison to his outer thighs. Although his quads were well developed, his outer thighs were overpowering his inner thighs and pulling his kneecaps toward the sides of his legs. The muscular imbalance between his abductors and adductors was planting the seeds for a knee-related injury. You can perform isolation exercises, such as weighted leg lifts, to strengthen either your inner or outer thighs. If you aim to avoid knee injuries, be aware of the relative strength of different regions of the same leg muscle.
The Bane of Tight Calves
The repetitive motion of pedaling puts a lot of pressure on your calf muscles, causing them to tighten. If your calves are too tight, your feet will flatten into a toe-down position, putting excessive stress on your knees, heel cord and plantar fascia, or the connective tissue supporting your arches. Inflexible calves can also make you more vulnerable to bursitis in the knee -- an inflammation of the fluid-filled sacs that cushion the tissues surrounding your knee joints. Regularly stretch your calf muscles to avoid these muscular imbalances. For example, sit on a chair with your feet planted on the floor. While keeping your heels on the ground, lift your toes and hold the stretch for 20 to 30 seconds. Heel drops on a raised platform, such as a stair, will also stretch your calf muscle, Achilles tendon and ankle.