by Zeina Khawam, R.D. Fitness Training
Female athletes have specific caloric and nutritional needs for performance in sport.
Up until puberty, nutritional needs for boys and girls are very similar. But with the increased levels of testosterone in men after puberty, they genetically tend to have larger muscle mass and a lower body fat percentage. Because of this and other physiological differences, caloric and nutrients needs are different in post-puberty females compared to their male counterparts. Below are the most common differences seen.
Caloric (or energy) needs are based on factors like age, sex, weight, height, muscle mass, and everyday activity. Therefore, if males genetically have larger muscle mass, their resting metabolism will be higher, resulting in higher energy needs. Still, although females have lower energy needs than males, female athletes need more calories than non-athlete females due to the increased physical activity.
Iron is a mineral that is responsible for transporting oxygen to our muscles. Iron deficiency can lead to anemia, which has symptoms of mental and physical fatigue, which would have an effect on overall performance. Women have higher iron requirements than men because they lose a lot of iron each month through menstruation. Also, if a female athlete restricts caloric intake to achieve a certain physique, they are at an increased risk of deficiency. Therefore, it's recommended that women consume more iron than males.
Some good sources of iron include beef, eggs, dark leafy greens, beans, lentils, tuna, tofu, and fortified cereals. Remember to add a source of vitamin C like citrus, strawberries or red peppers when you consume an iron-rich food that is plant-based!
Calcium & Vitamin D
Calcium and vitamin D are important for healthy bones, teeth, muscles, nerves, and proper hormone function. Although dairy products are the greatest source of calcium and vitamin D, we can also find them in fortified soy beverages, canned salmon or sardines with the bones, and fortified orange juices. Vitamin D on the other hand can be obtained from sunlight coming into contact with our skin during the summer months in Canada.
If a female athlete eats fewer calories to lose weight to favor performance, they may not reach their calcium intake requirements. Also, a low caloric intake may disturb their hormonal balance which would have a further negative effect on bone health. In this case, an increased calcium intake of 1500 mg/day (normally 1000 mg/day in men and women 19-50 years old) may help to improve calcium balance.
The Female Athlete Triad
With the combination of increased nutrient and caloric needs, and the pressure to achieve a certain physique, females are at a higher risk of certain conditions like disordered eating, menstrual disturbances, and osteoporosis. When these conditions occur at the same time, we get a syndrome called the female athlete triad.
Unfortunately, many female athletes, especially those in sports emphasizing leanness like gymnastics, ballet, and aerobics tend to practice unhealthy weight-loss methods like restricting food intake, excessive exercise, and the use of laxatives to achieve their desired physique. Although hockey is not one of those sports, disordered eating habits can happen to anyone. If you are working with or are close to female athletes, some warning signs are visible, such as rapid weight loss, poorer performance, fatigue, stress fractures. They will often be preoccupied with weight and food and may eat alone, avoid team meals, avoid certain food groups, and go to the washroom after every meal or snack.
In women, an unbalanced diet (due to the avoidance of certain food groups), inadequate intake considering high exercise levels and excessive training may increase the risk of menstrual abnormalities. Menstrual irregularities are defined as no menstruation by age 16, missing three consecutive periods or having periods that occur at intervals of greater than 35 days. These women should be evaluated by a doctor.
Osteoporosis refers to low bone mass and is often associated with low calcium and vitamin D intake and sedentary behavior. In female athletes however, the main risk factors are low estrogen levels and other hormonal changes due to menstrual irregularities, especially younger women still reaching their peak bone mass. This low bone mass increases the risk of stress fractures, as well as fractures later in life. This is why females with menstrual abnormalities require more calcium and vitamin D.
If the triad is suspected, the involved athlete should be encouraged to seek medical attention. If the individual refuses, the concerned coach, parent or friend should consult with a physician directly as treatment often requires a team of specialists including a doctor, dietitian, psychologist, and the support of those around the individual.
Note: The information included is based on the best available evidence at the time and may not be applicable for all athletes. Please consult your local dietitian to get personalized advice.
Eguiguren, M. L., & Ackerman, K. E. (2016). The Female Athlete Triad. Contemporary Pediatric and Adolescent Sports Medicine The Young Female Athlete, 57-71. doi:10.1007/978-3-319-21632-4_5
Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. (2016).
Rosenbloom, C. (2012). Sports nutrition a practice manual for professionals. (5th ed.). Chicago, Ill.: Academy of Nutrition and Dietetics.
Zeina is a registered dietitian-nutritionist and is part of l’Ordre professionnel des diététistes du Québec and Dietitians of Canada. She currently works at Le Fitness Loft Kinesiology Clinic in Dorval where she consults an active clientele that desires to change their lifestyle habits, whether it is to lose weight, increase muscle mass, improve performance or simply live healthier. Zeina has a passion for teaching and conveying her knowledge about overall healthy eating habits and makes sure every client receives personalized recommendations based on their lifestyle and preferences. For more tips and tricks visit www.TheFoodieRD.com