More powerful with less weight

You hear this phrase in many sports: “It’s easier with a few kilos less.” In endurance sports like running or cycling, it’s often the watts per kilogram of body weight that matter. Having less mass to move uphill sounds like an advantage, and images of slender elite athletes reinforce that impression. In gymnastics, ballet, ski jumping, and sports with weight classes, too, a slender body is quickly seen as a prerequisite for success.

For adolescents with early-stage anorexia, this idea gains dangerous support. Starving oneself suddenly seems reasonable, justified by athletic goals, and even recognized by others. The desire to control one’s own body is disguised as ambition. Parents and coaches praise the discipline, while meal portions keep getting smaller. Thus, the line between ambitious training and an illness blurs without anyone noticing.

In the first few weeks, the plan seems to be working. Losing a few kilos improves some metrics in the short term; uphill sections feel easier, and race times get faster. One runner breaks her personal best and is convinced she’s found the right path. On top of that, she receives praise from others and feels a sense of strength.

When food is scarce, the body releases increased levels of stress hormones. Many people affected report inner restlessness and a strong urge to move, which feels like extra energy. This high is deceptive. It’s based on the body’s alarm response, not on real training progress. As soon as energy reserves are depleted, the effect reverses, and performance plummets. This is precisely where the trap lies: The initial boost is interpreted as proof and fuels further starvation, even as the body has long since begun to break down.

If the energy deficit persists for weeks, sports medicine experts refer to it as RED-S (relative energy deficiency in sport). This refers to a condition in which the body consistently receives less energy than it needs for training, growth, and basic functions. Both girls and boys are affected. The body then scales back key functions to conserve energy, and this affects nearly every organ system.

• Muscles: The body breaks down protein from muscle tissue. Strength decreases, and muscle recovery after training stalls. Performance declines, often despite increased training.
• Bones: Low energy availability reduces levels of important hormones. Combined with a lack of estrogen, this increases the risk of stress fractures and, later on, bone loss (osteoporosis).
• Heart and Circulation: Heart rate and blood pressure drop. In severe cases, life-threatening cardiac arrhythmias may occur.
• Menstrual Cycle: In girls, menstruation stops (secondary amenorrhea). It usually returns only after sufficient weight gain.
• Immune system: The immune system weakens, infections become more frequent, and recovery takes longer.
• Concentration and Mental Health: The brain suffers from the deficiency. Thoughts revolve around food and weight, and mood and sleep deteriorate.

This is particularly problematic during puberty because the body is already using a lot of energy for growth. For more information, see “Eating Disorders and Puberty.”

In sports, starving oneself can often be disguised as hard work, because self-denial and toughness are considered virtues there. This makes it all the more important for parents to pay close attention. Here are some signs they can look out for:

• Training despite injury, illness, or exhaustion, plus secret extra training sessions.
• Meticulously counting calories and skipping meals on days off from training.
• Frequent stress fractures or injuries that heal only slowly.
• Missed periods, constantly cold hands, and frequently feeling cold.
• Irritability, withdrawal, and declining performance despite more intense training.
• Unusual eating behaviors, such as eating only “healthy” foods, chewing food for a long time, or making excuses during family meals.

If weight becomes a constant topic of conversation, the Weight Monitoring (Parent’s Guide) page can help you make sense of it. A single sign means little on its own. Multiple signs over several weeks are a reason to take a closer look and initiate a conversation.

An eating disorder that is detected and treated early has a significantly better chance of full recovery, which is why every month counts. If an eating disorder is suspected, the first point of contact should be the pediatrician, supplemented by a sports medicine evaluation. Any abnormal heart, bone, or menstrual cycle readings should be evaluated by a doctor. The coach should also be involved to ensure that training does not further exacerbate conditions that are harmful to the body. Specialized outpatient clinics for eating disorders at university hospitals often have waiting lists, so it’s worth making an early inquiry, even if a diagnosis hasn’t yet been confirmed.

Rückenwind Support for parents through coaching and counseling. Janike is a social worker and parent coach currently training to become a child and adolescent psychotherapist; she is not licensed to practice medicine and does not make diagnoses. The diagnosis and treatment of an eating disorder or a relative energy deficiency can only be carried out by a child and adolescent psychiatrist (KJP) or a medical or psychotherapeutic specialist.