The Effects of Flexibility Training on Performance and Development
Movement is caused by the contraction of muscle fibers attached by the tendons on either side of a given joint (i.e. the elbow joint is flexed by contraction of the biceps muscle attached to bones of the upper and lower arm). In athletics this is called dynamic or “active” ROM (range of motion), where the movement of the joint is caused by a muscular contraction. Active ROM, or athletic specific movement, is most effected by the force of the muscle contraction and the flexibility of the joint being moved.
In discussions of flexibility, people most often refer to their ability to stretch a muscle that is at rest. This is called static or “passive” ROM because the joint is being moved with assistance. The maximum static ROM achievable at any given joint in the human body is effected by the elastic properties of the muscle and tendons that attach across joint. It is these elastic properties that are most effected by flexibility training. Joint structures vary greatly between individuals and this has to be considered when assessing flexibility standards in different kinds of athletes. Research has shown that the greatest limiting factor of passive ROM in individual athletes is the structure of the joint itself and not the tissue connected to it. So, even after regular flexibility training there will be a limit as to how much movement the joint can achieve.
Does flexibility training improve performance?
There is a good deal of research into the effects of flexibility in “working muscles” that suggests that making muscle tissue more pliable can have a positive effect on performance. Under similar conditions, pliable muscle is more mechanically efficient and will fatigue at a slower rate than stiff muscle. Muscle that is tight tends to be more susceptible to cramping and muscle pulls. Tight muscle can also expose an athlete to tendonitis and other overuse injuries. While it has not been clinically proven that more flexible muscle has the capacity to produce more power it has been shown to hold up better under the stresses of exercise and is less susceptible to common soft tissue injuries that disrupt the training process and delay positive training effect.
When speaking of flexibility and cycling performance, the focus is placed on the opposing forces of muscle contraction and relaxation and their effects on the relationship between passive and active ROM during the pedaling movement. As muscles fatigue they become less flexible and present resistance to the movement of the hip, knee and ankle joints as the pedals rotate. This causes one muscle group to work harder to move the joint because the less flexible, opposing muscle group is resisting the movement (i.e. tight hamstrings will provide resistance in flexing the hip to lift the knee to the top of the pedal stroke). Muscle that is more pliable will offer up less resistance as they fatigue on the bike. Static stretching can be used effectively on the bike to help to dissipate the tension and allow the muscles to relax and work more efficiently.
Passive vs. Active ROM and Performance
Holding a passive stretch is a completely different motion than that caused by sports specific muscle contraction and repetitive joint movement. This makes passive ROM a less reliable measure of flexibility when related to athletic performance. Active ROM relates to the force of an opposing muscle that is required to stretch a previously contracted (resting) muscle back to the ready position in a sports-specific movement. For example; in cycling the ease with which the hamstrings and glutes can relax and allow the contraction of the hip and knee flexors to lift pedal has a greater impact on performance than the passive flexibility of these muscles off the bike. While increased passive ROM does improve mechanical efficiency and reduce the risk of injury it seems that increasing active ROM and not passive ROM has a greater impact on cycling performance.
Improving active ROM
The principle of specificity applies to flexibility training just as it does with other components of training like speed, power and endurance. Any exercises intended to increase active flexibility need to be progressive, specific and similar to the movements to be performance on the bike. The first thing to consider is the specific joint movement and muscle recruitment required for the activity. For cycling the prime movers would be the extensors and flexors of the hip, extensors and flexors of the knee and extensors and flexors of the ankle.
While pedaling will improve the functional capacity of these muscle groups, improvements in active ROM will require additional training in a sports specific movement beyond that achievable on the bike. One example of this kind of training is light resistance work that isolates the muscles in a ROM beyond that achieved on the bike. Many standard strength training movements can be taken to this limit, with light resistance, thus increasing both strength and flexibility.
Other exercises can be used to reduce active stiffness in the muscle and increase flexibility. Examples of this would be high knee raises that work the hip flexors and straight leg hip extension that targets the glutes and upper hamstrings. Both of these movements are cycling specific but can be performed beyond the active ROM achieved on the bike. These exercises can be done with body weight resistance only to reduce stiffness and increase active ROM and muscle function on the bike.
Active ROM training during Warm Up
It is important to warm up at the beginning of every training session. Active ROM stretching requires the muscles to contract, which engages the energy systems that fuel the muscle and generates heat. In preparation for a training ride, a warm up session using active ROM flexibility training would look something like this. Walk slowly for 2-3 minutes gradually increasing the height of your knee lift until you are in a full, high step motion for the last 30-45 seconds. Follow this with 2-3 minutes of normal walking gradually increasing the length of your stride until you are walking with your hip fully extended between steps for the last 20-30 seconds. Then complete the routine with a 1-2minutes of shorter stride walking gradually increasing to a full extension of the ankle and a spring off the toes for the last 15-20 seconds.
Follow this 3-step routine with a few minutes of gentle passive ROM stretching of the major upper and lower body muscle groups and repeat the routine again. This routine will energize the aerobic system while it loosens and warms the muscles in a full, active ROM. Once on the bike follow up with 15-20 minutes of moderate intensity riding at a brisk pedal cadence (90+ RPM) to complete the warm up. Including active ROM flexibility into your warm up routine will help you improve functional ROM on the bike and develop improved muscle memory for a strong and efficient pedal stroke.
It is also important to address stiffness and flexibility in the upper body during the warm up. The lumbar spine, upper back, neck shoulders, chest, arms and hands are all actively involved in riding the bike and need to be prepared for training. The active ROM in all these areas can be increased using simple flex/extend and rotate movements. Gentle twisting of the torso and bending front/back and side/side at the waist will loosen the truck. Arm swings and shoulder rotation will loosen the upper back and shoulders. Joining the hands behind the back will stretch the chest, front of the shoulders and biceps. The neck area can be stretched using gentle front/back and side/side movements. With any type of neck exercise great caution should be taken not to over extend the small muscles in the neck and upper spine.
ROM, flexibility and injury prevention
Stiffness and restricted ROM will increase the risk of soft tissue injury and joint strain. Flexibility requirements vary greatly between sports and it is important to identify these before developing a flexibility routine. For cycling the main concern is muscle fatigue and not muscle injury. However there are muscle groups that will cause difficulty and injury for riders if flexibility is ignored.
The knee joint is the most effected and at highest risk of injury by cycling. The muscle groups that put stress on the knee joint are the Quadriceps (knee extensors), Adductor Group & Gracilis (medial thigh muscles), Sartorius (anterior knee flexor) on the anterior plane and the Gastrocnemius (posterior knee flexor) and Hamstring Group (posterior knee flexors) on the posterior plane. The Iliotibial Tract (tensor fasciae latae/IT band ligament) runs from the crest of the hip bone (ilium) to the lower leg bone (tibia) and acts as a lateral knee stabilizer. A lack of flexibility in this tract can cause sever knee strain and result in a painful and debilitating injury. Adequate flexibility in all of these muscle groups is important to injury free cycling.
Any pre-exercise stretching for cycling, passive or active, should be done within your normal, comfortable ROM and with the spine in a natural posture and alignment. Static stretches can be held up to 60 seconds and should never cause strain or pain in the muscle. Very stiff muscle should be stretched gradually and progressively over time to increase flexibility. It is important to avoid any strain to the tendons that hold the joints together or the muscle attachments when stretching. This is especially important when using static stretching where good posture and mechanics will help prevent injury.
In conclusion
Flexibility is important to your health and athletic development. Choosing the proper methods and movements for a flexibility program is very important. It is not wise to pattern you’re stretching and flexibility training after what you see other riders doing. You will need to do some personal assessment of your own flexibility and determine what areas need work and which exercises are most appropriate. Consulting a professional trainer at your local health club is a good place to start. They will take you through a flexibility assessment session and can prescribe an appropriate stretching program based on your goals. If you approach flexibility training with a good plan you will be able to improve your performance and prevent unnecessary injury.