Taboo topic in cycling: eating disorders

In many sports, the advantages of a low body weight outweigh the disadvantages. Lightweight ski jumpers fly further. In sports with weight classes (boxing, weightlifting, judo, lightweight rowing, wrestling and others), body weight is a central component and sometimes more important than training. In addition, losing weight (“making weight”) can give you an advantage when competing in the next lower weight class against relatively weaker opponents. In equestrian sport, a show jumper puts less weight on his horse. A lighter jockey lets the horse run faster. A rider in the racing discipline may not weigh more than 55 kilograms. In weightlifting, the lighter athlete wins if the performance is the same. In sports with aesthetic requirements, slimmer bodies sometimes even get better marks from the competition judges. In endurance sports such as triathlon, running and cycling, the chances of winning a competition are also higher with a lower weight.

Fighting against your own body weight

Although there are no weight classes in cycling, the ratio of strength to weight is also particularly important here. Similar to martial arts, for example, larger athletes have a higher strength and performance potential. In martial arts or weightlifting, the advantage of larger lungs, more muscles or longer limbs etc. is partly limited by the introduction of weight classes. Athletes are tempted to slip into the next lower weight class by reducing their body weight, where they are then superior to their often smaller competitors. The official weigh-in before the competition then becomes the actual competition: the fight against one’s own body weight. It is not uncommon for unhealthy methods to be used to minimize body weight immediately before going on the official scales. Common methods include diuretics, even though these are usually on the banned list of the World Anti-Doping Agency (WADA). Side effects due to water and electrolyte excretion such as muscle cramps or cardiac arrhythmia are accepted. Diuretics to increase performance are out of the question for cyclists. There are no weight classes in cycling. Depending on the discipline, weight plays a more or less important role. However, less is usually more. Body weight is least important in track cycling. Additional weight slows you down in the acceleration phase. Once a certain constant speed has been reached on a flat surface, the rider’s power and performance are the only factors that count, disregarding friction and air resistance. Otherwise, even on hilly terrain, cyclists benefit significantly from lower body weight. Low weight is essential for mountain bikers. Reducing body fat is the method of choice here. Weight loss is always accompanied by a greater or lesser loss of so-called “lean mass”. The main part of the weight of the lean mass comes from the muscles – if water is neglected. Even if targeted training during weight reduction results in a loss of the muscles required for cycling, particularly in the legs, muscle mass in other parts of the body is reduced. Initially, this even appears to be an advantage for the cyclist. Muscle mass always means more body weight, which is undesirable. For example, most professional cyclists have noticeably narrow upper arms and upper bodies. Extensive training of the arms and upper body is taboo for racing cyclists. Only sprinters can still benefit to a small extent from muscle strength in these areas. However, the lack of muscles above the waistline also has negative effects. Strong back muscles prevent pain in this area in particular and correlate with well-developed abdominal muscles. A strong torso and generally well-developed muscles cushion the body, particularly in the event of a fall, and prevent more serious injuries, including in the shoulder area.

Skeletal muscle is the largest organ in our body. On average, it makes up 35 percent of our body weight. Our body has over 600 skeletal muscles. The word skeletal muscles includes all muscles that can be actively moved with our consciousness and will. As the name suggests, the majority of skeletal muscles are connected to the skeleton, such as the arm and leg muscles. During movement and contraction, our muscles release hormone-like messenger substances called myokines. Several hundred types have been identified so far, but they have not yet been fully researched. The myokines travel from the muscles to other parts of the body via the bloodstream. Myokines belong to the peptide/proteohormones and are therefore special proteins that perform hormone functions. They act as messenger substances and allow the muscles to communicate with other parts of the body. Not only has it been found that exercise and the myokines released with it can improve acute illnesses, myokines are also very effective in prevention. Obesity and diabetes, for example, can be prevented by increasing insulin sensitivity. When blood sugar rises, a small amount of insulin is sufficient to channel the excess sugar into cells. At the same time, fat metabolism is increased by stimulating the breakdown of fat (lipolysis) in adipose tissue. Ordinary white body fat can be “browned” with the help of myokines. White fat is enriched with mitochondria and thus becomes more similar to the original brown adipose tissue, which burns fat to produce heat. Myokines not only protect against obesity and diabetes but also against cardiovascular disease and metabolic syndrome. Some myokines are able to limit the progression of cancer and cancer-related cachexia. Cancer cells hide from our immune system. They camouflage themselves so that our immune cells do not fight or eliminate the defective cancer cells. Certain myokines, in particular interleukin-6, guide the immune cells to the tumor so that they attack the cancer. In addition, interleukin-6 stimulates the formation of new immune cells and has an anti-inflammatory effect. Inflammation not only plays a beneficial role in cancer, but also in mental illnesses and other chronic diseases. For example, myokines can be beneficial in cases of depression or rheumatism. With advancing age, many people suffer from sarcopenia and osteopenia or osteoporosis. Sarcopenia is characterized by increasing loss of muscle strength and muscle mass in old age. At the same time, many suffer from reduced bone density (osteopenia), which often leads to the disease osteoporosis – also known as bone loss. Restricted mobility leads to an increase in falls. Serious injuries and bone fractures can be the result. It used to be thought that exercise only protected against osteoporosis through mechanical stimulation. In the meantime, a whole cocktail of myokines has been identified, which are released by muscle contraction and not only ensure improved bone density and bone stability, but also stimulate the formation of new bone. At the same time, the formation of new muscle mass is increased. Therefore: more muscle is better. I have dedicated a separate article to the topic of osteopenia as a risk for cyclists (here). Low body weight is mainly found among touring cyclists and especially among mountain specialists in road cycling. The latter have – in addition to the ability to achieve a relatively high continuous power output – an extremely low total weight. Off-road cycling, such as mountain biking or cyclocross, places additional strain on the supporting muscles. Fast, short and hard starts are required and, as in sprinting, place completely different demands on the muscles. Different muscle types take over here. Studies show that mountain bikers are less at risk of developing osteopenia than road cyclists.

The BMI (body mass index) as a measure?

How much body weight is too much or too little? The BMI (body mass index) has now become widely used as a measure of ideal weight. The BMI relates body weight and height together. By definition, the BMI results from the body mass in kilograms [kg] in relation to the square of the body length in square meters [m²]. This results in BMI figures from 16 to 40 in [kg/m²]. At lower or higher values, the lives of people with such figures are in acute danger. A normal weight for adults is between 18.5 and 25. However, the BMI as a number says nothing about a person’s gender, age or stature, which do have an effect on weight. Men usually weigh more than women, even if they are the same height, as their bodies have a different composition. For this reason, the BMI figures are categorized by gender for interpretation purposes, including by the German Nutrition Society (DGE). There are special tables for gender and age to help with the classification of BMI figures. The more muscular a person is, the higher their weight. Muscles have a higher specific weight than body fat, for example. And this is where the trap snaps shut for athletes. Athletes have more muscle than the average person. Even with very low body fat, the extra muscle drives up the BMI. Strength athletes often end up in the upper range or even in the overweight range. In morbidly lean athletes, muscles can contribute to a normal BMI and mask the physiological underweight. In principle, body fat is not harmful as long as it does not take on morbidly obese proportions. Too little body fat leads to health complications and illnesses in the long term. Even if the body fat percentage is still within normal limits, damage can occur during the weight loss phase due to a lack of energy and/or vitamins or minerals.

If eating behavior is disturbed and energy intake is chronically low, this is referred to as anorexia athletica. Anorexia is the medical term for anorexia. The addition athletica assigns this form of anorexia to the special group of athletes. This goes unnoticed at first and for longer, especially in men. Women of childbearing age, on the other hand, often suffer from cycle disorders such as long intervals between periods (oligomenorrhea) or absence of menstruation (amenorrhea) due to a lack of energy. In addition to irregular or absent periods, there is also a disorder of bone metabolism with a risk of reduced bone density (osteopenia) or osteoporosis. The term “female athlete triad” was initially coined to describe the pathological underweight, with a comprehensive clinical picture. In the meantime, the disease has also been extended to male athletes. Experts refer to it as the Relative Energy Deficiency in Sports (RED-S). The term expresses the fact that there does not necessarily have to be an absolute energy deficit for illness to occur. Both the body fat percentage and the energy intake can appear to be sufficiently high. In reality, the body receives too little energy and some metabolic processes are – initially unnoticed – throttled back or switched off in order to save energy. Athletes need less energy due to the reduced metabolism. They then maintain their low body weight and appear to eat enough, as no further weight loss occurs. This ignores the fact that important bodily functions are already reduced or stopped. The other group with RED-S are athletes who temporarily consume extremely little energy and later compensate for this, so that their body weight stagnates or even increases. This is stress for the body and cortisol levels are elevated. Athletes sometimes look healthy. Young athletes in particular are initially successful in reducing their energy intake and losing weight during their sporting careers, before a downward spiral finally sets in. Unexplained digestive complaints often occur at the beginning and tempt athletes to further limit their food intake. Susceptibility to injury and infection gradually increases. Sleep problems and psychological symptoms such as depression can occur. The hormone balance is disturbed. In men, testosterone production can fall. Male athletes even mistakenly gain positive aspects from a subsequent testosterone therapy with a doctor’s prescription of the hormone, as they expect a performance-enhancing effect. Caution is advised here! Supplementing testosterone without there being a deficiency reduces the body’s own production in the medium term. The measured testosterone level does not necessarily reflect the entire testosterone status. Testosterone is subject to a daily rhythm and is directly related to the length and quality of sleep. Free testosterone is not medically measured but estimated.

But what to do if low body weight leads to victory even if it damages the body in the long term? Just as there is an ongoing discussion about the harmful effects of doping substances, awareness of the problem of RED-S is now developing. In some sports, there are now regulations in place to protect against morbid underweight. In long jump skiing, according to the rules of the FIS, an athlete must have a BMI of at least 21 in order to be allowed to use the full ski length of 145 percent of their height. Those who are lighter must compete with shorter skis. A similar procedure would also be conceivable in cycling. If you are too light, for example, additional weight is “screwed” onto your bike. Being underweight is still tolerated – to the detriment of the athletes. With growing awareness in the sports associations and among the athletes themselves, morbid weight will hopefully soon be put a stop to in cycling too.




Torstveit MK, Sundgot-Borgen J. Participation in leanness sports but not training volume is associated with menstrual dysfunction: a national survey of 1276 elite athletes and controls. Br J Sports Med. 2005 Mar;39(3):141-7. doi: 10.1136/bjsm.2003.011338. PMID: 15728691; PMCID: PMC1725151.

Barbalho SM, Prado Neto EV, De Alvares Goulart R, Bechara MD, Baisi Chagas EF, Audi M, Guissoni Campos LM, Landgraf Guiger E, Buchaim RL, Buchaim DV, Cressoni Araujo A. Myokines: a descriptive review. J Sports Med Phys Fitness. 2020 Dec;60(12):1583-1590. doi: 10.23736/S0022-4707.20.10884-3. Epub 2020 Jun 23. PMID: 32586076.

Huang Q, Wu M, Wu X, Zhang Y, Xia Y. Muscle-to-tumor crosstalk: The effect of exercise-induced myokine on cancer progression. Biochim Biophys Acta Rev Cancer. 2022 Sep;1877(5):188761. doi: 10.1016/j.bbcan.2022.188761. Epub 2022 Jul 16. PMID: 35850277.

Severinsen MCK, Pedersen BK. Muscle-Organ Crosstalk: The Emerging Roles of Myokines. Endocr Rev. 2020 Aug 1;41(4):594–609. doi: 10.1210/endrev/bnaa016. Erratum in: Endocr Rev. 2021 Jan 28;42(1):97-99. PMID: 32393961; PMCID: PMC7288608.

Stephen R, Hongisto K, Solomon A, Lönnroos E. Physical Activity and Alzheimer’s Disease: A Systematic Review. J Gerontol A Biol Sci Med Sci. 2017 Jun 1;72(6):733-739. doi: 10.1093/gerona/glw251. PMID: 28049634.

Kaji H. Effects of myokines on bone. Bonekey Rep. 2016 Jul 20;5:826. doi: 10.1038/bonekey.2016.48. PMID: 27579164; PMCID: PMC4954587.

Warner SE, Shaw JM, Dalsky GP. Bone mineral density of competitive male mountain and road cyclists. Bone. 2002 Jan;30(1):281-6. doi: 10.1016/s8756-3282(01)00704-9. PMID: 11792598.

Bone Status in Professional Cyclists – Georg Thieme Verlag KG Stuttgart · New York F. Campion1 , A. M. Nevill2 , M. K. Karlsson1 , J. Lounana3 , M. Shabani3 , P. Fardellone4 , J. Medelli Int J Sports Med 2010; 31(7): 511-515 DOI: 10.1055/s-0029-1243616

Olmedillas H, González-Agüero A, Moreno LA, Casajus JA, Vicente-Rodríguez G. Cycling and bone health: a systematic review. BMC Med. 2012 Dec 20;10:168. doi: 10.1186/1741-7015-10-168. PMID: 23256921; PMCID: PMC3554602.

Nieschlag, E., Vorona, E. Doping with anabolic androgenic steroids (AAS): Adverse effects on non-reproductive organs and functions. Rev Endocr Metab Disord 16, 199–211 (2015).

Statuta, Siobhan M. MD The Female Athlete Triad, Relative Energy Deficiency in Sport, and the Male Athlete Triad: The Exploration of Low-Energy Syndromes in Athletes, Current Sports Medicine Reports: February 2020 – Volume 19 – Issue 2 – p 43-44 doi: 10.1249/JSR.0000000000000679

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