Scientific research and science applied to sport in recent years has made it possible to make many changes and improvements in the methods and ways in which they are practiced. Until about 30 years ago in Europe there were not even mountain bikes, with the passing of the decades and the evolution of technologies, of more in-depth studies also on materials, on correct structures and components but not only, we wondered if it was possible improve all those technical factors, including postural ones, which would make pedaling optimal (remaining in the cycling field) effective and above all “healthy”.
In cycling as in any other sport or athletic effort, a body structure with strong and trained bases is essential for the athlete. This is the key to achieving top-level performance and at the same time avoiding injuries. Often, however, there is a lack of awareness of which are the muscle groups on which to focus the training focus in the different phases of the season. In this article we will analyze the muscles activated, and on which it will be important to focus attention, in cycling. In fact, many cyclists fall into the "trap" of thinking that the effort associated with this activity is totally / solely focused on the muscles of the lower body, underestimating the role of the arms, abdomen and back, in short, the upper body. . All parts of the body have to work together, for example, only to stabilize the bicycle and concentrate maximum power on the pedals.
We deal with an overview of the muscles activated during a cycling training session and then go on to analyze more specifically the biomechanics of pedaling and the related muscular implications. The arms represent two of the five points of contact with the bike and contribute primarily to its maneuver but also to a "stabilizing" action on the rest of the body during pedaling. Just think of the “out of the saddle” phases (uphill or in a sprint for example) here the arms will play a key role (note the tension and flexion of the arms in some photos of athletes in sprint finishes). At the same time the shoulders, deltoid muscles and rotator cuff will be subjected to a continuous effort during the activity, being the first connection between the arms and the trunk and having to support the weight of the upper part of the body with respect to the force of gravity, in any position (standing, sitting or in a sprint). Neck muscles parallel to the shoulders will be continuously activated (splenium and extensors). Let's move on to the back and chest, underlining how the cyclist's back is subjected to a continuous hypertrophic situation due to the stress given by the position and how parallel the chest muscles (intercostals, pectorals ...) are instead involved mainly during extreme efforts such as long climbs or challenging or sprint. Finally, before moving on to the legs, it should be emphasized that the abdomen is also of primary importance in cycling. In addition to determining a good part of the stability to the rest of the body, they are very important to counteract the strong back muscles (normally well developed in cyclists). A back-abdomen imbalance could be at the basis of a destabilization of the skeleton (spinal imbalance) potentially leading to localized pain in the lower back, conditions that often become debilitating for the athlete. We close this general introduction by considering, of course, the legs and hips as the fundamental driving force of the cyclist. It is no coincidence that professional cyclists treat their legs as if they were jewels.
To understand in a more specific and in-depth way the muscle activation related to the cyclist's legs we will analyze in detail the biomechanics of pedaling. Taking, for example, into consideration professional cyclists inclined to take care of every detail, the care of the pedaling analysis is a detail that can make a big difference, which leads the athlete to excel over an opponent who could be physically stronger, but who he can't express his strength on the pedals to the fullest. Pedaling is the result of the sum of the forces applied by each single leg which, placed at 180 degrees from the other, completes a full 360-degree revolution. Cycling adopts a closed kinetic chain, in fact at the completion of each revolution the foot is in the same starting position. Pedaling can be analyzed by dividing it into 4 phases. Push (extension) phase in which almost 65% of the total forces expressed during the entire movement are applied, the second is defined as transition, transition from push to traction in which the leg completes the extension without reaching maximum opening of the knee (12% of total strength). Phase 3, traction, the limb will pull upwards in this phase, finally in phase 4 it will pass from the traction phase to the push phase. To pedal correctly and express the correct power on the pedals, there are position parameters that every cyclist should respect. These parameters concern the length of the cranks, the positioning of the “cleats” with respect to the pedal, the height and the setback of the saddle, and the elongation on the bike. These parameters are strictly individual, made unique by the physical and anthropometric characteristics but also by the muscular characteristics and joint mobility. For example, the length of the cranks must be related to the length of the femur (bone that often works parallel to them), and will allow, on the one hand, to best express the force produced by the body on the bike, and on the other to avoid pathologies or injuries to the load. of the quadriceps femoris or patella. The positioning of the "cleats" will instead be fundamental to avoid pedaling too much on the sole or toe with consequent possible inflammation at the tendon level, the point of the foot where the force produced by pedaling is best managed is located in the center of the first metatarsal head, the pedal pin should get as close to this as possible. A parameter to obtain the most effective thrust during pedaling is the correct height and rear position of the saddle, during this phase (downward thrust) the optimal thrust angle should be between 25 and 30 ° . The height of the horse is usually taken into consideration to determine the saddle height of the individual, while, the rearward position of the saddle is "set" by considering, when the pedal is placed at 90 °, when the pedal pivot will be at the same advance. vertical patella (plumb-line patella-pedal pin). The variables, especially in professional cyclists in this case are many, in most cases based on the discipline-specialization of the same, the pistard usually use a more advanced position (greater thrust on the pedals), greater setback instead for climbers (pedaling smoother with less maximum and minimum force peaks while pedaling).
Let's now analyze specifically the muscles involved in pedaling, constituted as mentioned by the succession of flexion-extensions involving the hip, knee and ankle joints without forgetting the upper body district. We start from the movement of the hip joint, the thigh remains in flexion throughout the pedal stroke without ever reaching full extension, the latter, which as mentioned represents the phase in which more force will be released (pedaling motor) is supported from the gluteus maximus muscle aided by the gluteus medius and gluteus minimus muscles and the extensor muscles themselves are flexors if the thigh is extended. Other hip extensor muscles are the hamstring muscles (hamstring, semimembranous and semitendinosus) put in tension by the knee extension. As for the flexion of the hip, the ileo-psoas intervenes. The joint most subjected to workloads, however, is the knee, the movements in this case are of large amplitude with the quadriceps femoris with all its components involved in the pushing and tailoring phase and internal rectus, bi-articular and mono hamstring muscles. -articulars (popliteal, short hamstring head) involved in flexion. Finally the ankle through the involvement (foot extension) of the triceps of the sura (calf) will allow to flex the leg in synergy with the hamstring. The calf is one of the longest stressed muscles during pedaling and is therefore one of the first to experience fatigue, accumulate lactic acid and possibly go against muscle cramps.
In this regard, it is curious to note, considering both competitive and non-competitive cyclists, how 85% of their injuries are linked to problems of a non-traumatic nature but of stress (repetitive strain injuries RSI's) with an estimated prevalence of knee pain () 42-65% in amateur cyclists. Most of these problems are the result of wrong set-ups or biomechanical alterations caused by fatigue (breakdown and loss of correct posture on the bike or pedaling movement). In fact, several studies have shown that as fatigue increases, the cyclist will increasingly tend to change position and consequently muscle activation to maintain performance. A 2008 study (Dingwell et al.) Reports after evaluating 10 professional cyclists in an ergometer cycle at 100% of their VO2 max reports how the curve, the movements of the trunk and above all the angle of action of the knees over time. underwent clear changes (Dettori and Norvell, 2006). All this to underline how important it is first of all to start with the right set-up to be able to make the most of one's potential but then remain concentrated even in moments of maximum effort since breaking down would mean on the one hand reducing the efficiency of the action and secondly throwing the basis for possible stress injuries.
To conclude, cycling is undoubtedly one of the healthiest cardio activities there is, however it is good both in the case of the athlete involved in this activity as the main sport and in the case in which it constitutes a complementary activity to become aware of which are the muscles involved, make a "biomechanical" analysis of what could be the best posture and attitude, in order to express one's potential with maximum efficiency, in a healthy way and without incurring injuries. It goes without saying that these considerations will become essential for the competitive athlete who trains daily and who will have to get the most out of every detail.
[Doctor in food science and technology; Master's degree in Biological Sciences (Nutrition and Functional Food); CSEN certified Instructor and Personal Trainer]
