Female athletes: training, nutrition and health
Female athletes need a clear head in training as much as a strong body. When energy, body weight and recovery go off track, eating disorders, amenorrhea and osteoporosis can begin to reinforce one another.
This is not only a concern for elite sport. The same logic applies to recreational exercisers who raise their training load too fast, eat too little or try to get lighter at any cost.
Why do female athletes need to talk about energy?
An athlete’s food is not just something to fill the stomach. As early as 1852, University of Tartu researchers G. Fr. K. H. Bidder (1810-1894) and C. E. H. Schmidt (1822-1894) wrote in their monograph “Digestive juices and metabolism” that the ratio of carbohydrates, fats and proteins is important in the human diet.
By the modern view, a sensible split in the diet of an average person is 55-60% of energy from carbohydrates, 10-15% from protein and up to 30% from fat. For athletes the emphasis often shifts toward carbohydrates: 60-70% carbohydrates, 10-15% protein and 20-25% fat.
Why? Because with a high training volume the body burns more energy. If that energy isn’t replaced, the body starts to economize where the athlete doesn’t notice right away: hormonal function, recovery, bone tissue and mental balance.
For female athletes, three interconnected problems have traditionally been discussed: eating disorders, amenorrhea and osteoporosis. In more recent scientific literature this link has been called the female athlete triad.
How do female athletes end up in the risk zone?
The body’s energy balance is in equilibrium when the energy from food covers its total energy expenditure. In practice, that simple sentence is far more complicated. Training camps, the competition season, school or work, the number on the scale and a coach’s comments can all affect how much an athlete actually eats.
Earlier studies have often shown an energy deficit in female athletes. It has since been argued that part of this may have stemmed from shortcomings in the measurement methods. Still, it is clear that in endurance sports, gymnastics, bodybuilding and ballet, the share of body fat can drop very low and being underweight can become a visible problem.
Being underweight doesn’t always mean an eating disorder. Often, adjusting the training load and nutrition helps. But the first step is honest recognition: the athlete and the coach must understand that the situation needs attention.
Eating disorders don’t always begin with big drama
The wish to be lighter, leaner or in shape faster can quietly turn into an obsession. This is especially dangerous when a trusted coach constantly talks about the athlete’s body weight and appearance. Frankly, a comment doesn’t even have to be malicious to leave a mark.
Eating disorders include, among others, the conditions anorexia nervosa and bulimia nervosa. These are not problems only for athletes. Anorexia has been described in roughly 3-5% of people, more often in women than in men. The prevalence of bulimia among school- and university-age girls can reach 5-20%.
Among athletes, the prevalence of eating disorders is on average 2-3 times higher than in the general population. Against this background, the term anorexia athletica has been used to describe anorexia in athletes and its particular features.
The picture is not the same everywhere, though. In studies done in Norway, the prevalence of eating disorders was almost identical among female athletes (603 individuals) and non-athlete women of the same age (522 participants): 12% and 11% respectively.
The signs of anorexia are considered to be persistent underweight, often 15-25% below normal, an intense fear of gaining body weight, a distorted image of one’s own body and, in women, amenorrhea as well. Typical of bulimia is recurrent binge eating: a very large amount of food is eaten in a short time, episodes can occur 2-20 times a week, and the amount consumed at one time can reach 3000 kcal or more.
Bulimia may be accompanied by deliberate vomiting, the use of laxatives and diuretics, or training to the point of self-oblivion after eating. A clinical diagnosis is of course a doctor’s job. In the gym, though, a red light should go on as soon as food, the scale and guilt start to run the athlete’s life.
Amenorrhea is not a normal sign of training
Amenorrhea means the absence of menstruation at an age when it should normally occur, where the cause is not pregnancy. Generally, amenorrhea is diagnosed when menstruation is absent for 3-6 consecutive months.
Primary amenorrhea means that menstruation has never occurred. Secondary amenorrhea means that previously regular cycles stop. Among female endurance athletes, menstrual disorders have been observed in, for example, almost 50% of distance runners.
So what actually happens? The body may sense that there is too little energy and too much training load. In response, it scales down functions that aren’t essential for short-term survival. The cycle is one of them.
The risk of amenorrhea doesn’t depend on any single thing. Often several factors add up at once.
- Excessive training load or a sudden increase in training load.
- Body fat mass that is too low or drops sharply.
- Loss of fat tissue in “critical” areas of the body, such as the thighs and buttocks.
- Excessively restricted eating, including a rigid vegetarian diet or a significant energy deficit.
- Eating disorders or disordered eating.
- Sport-specific characteristics, for example running and gymnastics compared with swimming or cycling.
- Emotional stress.
- Late onset of regular menstrual cycles, or heavy training loads before it.
- Amenorrhea unrelated to training, or a predisposition to it.
Among college-age track and field athletes, a link has been described between weekly training mileage and amenorrhea: weekly training volumes of 5 and 112 km were associated with menstrual disorders in 6% and 43% of cases, respectively. This shows well that training volume matters, but it doesn’t act alone.
Sports with a higher incidence of amenorrhea often fall into three groups.
- Sports where an athlete’s appearance influences the result, such as gymnastics, rhythmic gymnastics, figure skating and competitive dance.
- Sports where a low body weight is seen as a prerequisite for success, such as endurance sports and mountain climbing.
- Sports with weight categories, such as judo and karate.
Endurance sports aren’t all the same either. Amenorrhea has been observed more often in runners than in swimmers or cyclists.
What should female athletes know about bones?
Osteoporosis means thinning of bone tissue, bones becoming porous and bone mass decreasing. Bones become more fragile and break more easily. It has long been regarded as a problem of older people, but the risk can also rise in young female athletes.
Estrogens play a major role in the development of a woman’s skeleton. In healthy young women, bone mass and density increase until about age 28. The fastest and most important development takes place in early adolescence.
From age 35-40, women’s bone tissue begins to thin gradually, initially at roughly -1% a year. The drop in estrogen that comes with menopause can raise the rate of bone thinning to 3-6% a year for the 4-5 years after menopause.
In amenorrhea, estrogen production falls much as it does in menopause. As a result, bone development may stall or bone loss may speed up. The situation is especially serious if amenorrhea develops in adolescence or in the 20s, because what is lost is very hard to regain later.
Regular training can support bone density, but it doesn’t cancel out the effects of energy deficiency and hormonal disruption. Bone thinning has been observed in female endurance athletes with amenorrhea despite a high training load. In the worst case, frequent stress fractures and breaks start to hold back an athletic career.
Calcium is an important topic here. The daily calcium requirement of an adult is estimated at 800-1200 mg in different countries. During pregnancy and breastfeeding, a woman’s calcium requirement is considered to be 37-50% higher, i.e. 1100-1500 mg a day.
Female athletes often get less calcium from food than is considered necessary. For men this is a less common problem, except in sports where cutting body weight before competition is widespread, such as wrestling and judo. The reason is simple: how much calcium and iron you get is closely tied to the total energy content of your food.
This doesn’t mean that getting more calcium requires overeating. On an ordinary mixed diet, 60-75% of calcium comes from milk and dairy products. Fish and canned fish also provide calcium, especially when eaten together with the bones. Among plant foods, almonds stand out.
Calcium absorption is supported by lactose and vitamin D, as well as vitamins A and C, iron, magnesium and phosphorus. On the other hand, excessive protein intake can increase calcium excretion in urine. For example, doubling protein intake from one gram to two grams per 1 kg of body weight a day can increase urinary calcium losses by roughly 50%. Sodium and caffeine can also promote calcium excretion.
FAQ: female athletes and health risks
Is losing your period normal for an athlete?
No. In the training environment it is sometimes regarded as an ordinary side effect, but in fact it is a sign that something may be wrong with how the body is functioning. If your period is absent for 3-6 consecutive months, you need to talk to a doctor or a qualified health professional.
Does a low body weight always improve performance?
No. In some sports a lower body weight may give a short-term advantage, but energy availability that is too low undermines recovery, raises the risk of injury and can lead to eating disorders, amenorrhea and osteoporosis.
What can a coach do first?
A coach can stop overemphasizing the number on the scale and appearance, and look at the athlete as a whole: energy, sleep, recovery, cycle, mood and injuries. A simple truth: form built at the expense of health doesn’t last long.
Authors: Luule Medijainen, Vahur Ööpik
Source: University of Tartu health information material
Author: Greta
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