This June, Vanesa Rus and Sara Martínez, sports dietitians-nutritionists, have published an article in the latest issue of Sport Life magazine about the differences in the diet of sportsmen and women. Although the basis of the diet in both cases is similar, the slight differences that exist increase when practising sports and requiring both higher energy and other more specific nutrients.
Nutrition and sports performance
Nutrition is a determining factor for success in athletic performance. Thus, there are two key points for every athlete’s diet: meeting their energy needs and planning the different intakes throughout the day, also taking into account the training schedules.
The energy needs depend not only on the sex of the athlete since there are more factors come into play: weight, height, age, metabolic rate or basal metabolic rate, and the type, frequency, intensity and duration of training or sports practice.
It should be taken into account that in elite athletes who do long training sessions, such as performing several workouts in the same day, caloric expenditure can reach between 150 to 200 kcal/kg (reaching over 45 kcal/kg of body weight per day recommended), around 7,500 to 10,000 kcal per day in some competitions. As you might expect, the fast pace of everyday life compromises the consumption of food at regular intervals. This means that many times the intake carried out by athletes is lower than they should, and most times, it does not translate into a decrease in body weight. This is because the body, by receiving a lower intake than necessary, reduces its caloric expenditure at rest, in order to maintain its weight.
In addition, according to several studies carried out on athletes, some observe that after physical effort or training, hunger often decreases. For this reason, it is important to remember, sometimes for optimal nutrition, eat without feeling that hunger. Specifically, a study carried out on female athletes (Souza and Cols, 2004), showed a long history of deficient intake of carbohydrates and energy. This situation endangers the immune system and reproductive capacity, among other implications, as explained later in the athlete’s triad.
Main nutrients as an energy source
The type and intensity of physical exercise performed will determine the different macronutrients (carbohydrates, fats and proteins), depending on the metabolic pathways used during exercise.
However, based on the percentage of energy provided by each of the different macronutrients , carbohydrates will be the majority, followed by fats and finally, proteins.
- Carbohydrates: they must be the major source of energy for the athlete, representing around 50-60% of the total energy intake. The major sources are cereals (rice, quinoa, oats…) and their derivatives, potatoes, bread and fruits. Depending on the sport practised, the requirements will be higher or lower. For example: in moderate exercise plans in which the duration is approximately 1 hour a day, the diet should contribute between 5 and 7 g / kg body weight/day, while in aerobic endurance sports, in which the training suppose between 1h and 3h at a moderate-high intensity, the contribution should be increased to 7-12g / kg body weight/day. While in the case of practising extreme exercises of moderate-high intensity and long duration (> 4-5h) such as the titan desert, the contribution ranges from 10 to 12 g / kg weight/day.
- Fats: they should contribute around 25-30% of the total caloric intake. It is advisable to prioritise monounsaturated and polyunsaturated fats, due to their anti-inflammatory and cardiovascular prevention power. These are mainly found in oily fish, olive oil, avocado, pumpkin, sunflower or flax seeds, and dried fruits such as walnuts. In both men and women, it must guarantee a minimum amount of fat for proper metabolic and hormonal functioning.
- Proteins: it is essential that they are of high biological value to guarantee good muscle recovery. Proteins should provide around 10-25% of the total daily energy intake. The major sources are eggs, meat, fish, milk and their derivatives. They are also rich sources of protein, plant-based foods such as legumes, nuts, and soy derivatives such as tempeh, tofu or textured soybeans.
The factors that influence the protein needs of athletes are age, sex, lean mass, fitness level, routine and training phase. Thus, the protein needs of men are usually higher than those of women because of having a higher percentage of muscle mass. Regarding the exercise, for endurance athletes between 1.2 to 1.4 g / kg body weight / day is recommended, while for power training it raises the needs to 1.2-1.7 g / kg body weight / day. Being able to increase up to 2g / kg body weight / day.
What about the rule?
Another of the physiological situations that women have, unlike men, is the menstrual cycle. Menstruation is not a contraindication when practicing sports, but you must remember throughout the menstrual cycle women suffer hormonal changes, which affect sports performance. Therefore, it depends on the hormonal phase you are in, the way you train and eat, as well as the results, will be different.
The Follicular Phase comprises from day 1 to 14 after menstruation. In this phase, there is a greater sensitivity to insulin (with which carbohydrates proceed better) and a greater use of glycogen for energy. In addition, the metabolism goes down. By using more glycogen (to get the energy we need in sports), and less fat, the intake of sufficient carbohydrates will be essential.
The phase called Luteal (ovulation) runs from day 14 to 28 after menstruation. In this phase, however, there is a slight increase in metabolism, insulin sensitivity is lost, and the use of fats to provide energy to the body increases.
On the days of menstruation, our heart rate, body temperature and blood pressure increase. Losing blood and consequent loss of haemoglobin causes a decrease in the body’s ability to transport oxygen to the muscles. Therefore, the body’s work possibilities decrease, so on those days it is advisable not to do exercises that lead to high oxygen consumption. Additionally, you may feel increased fatigue and irritability. Therefore, this will be the week to carry out a gentler activity, always depending on the particular case of each one and its limitations. It is convenient not to stop exercising, since it produces the release of certain endorphins that will help us reduce the pain caused by menstruation,
In the days before menstruation, at the end of the luteal phase, cravings increase. This occurs because oestrogen and progesterone levels plummet. If it happens to you, do not think that you are an isolated case, it happens to the majority. For these moments, try not to succumb to temptation. You can eat fruit (those that are sweeter will be a good option) or biscuits with some protein food (turkey, cooked ham, nuts, fresh cheese…), that will give you a feeling of satiety. Do not skip any meals, try to eat every 3 hours, so you will not give time for hunger to appear. At times when you need to calm your anxiety with a sweeter food, you can opt for chocolate with a high percentage of cocoa, as it will provide you with a greater amount of antioxidants compared to other varieties.
Special nutritional needs in female athletes
Women have different requirements than men also in terms of vitamin and mineral. Today we will talk about three of them: Iron, Calcium and Folic Acid.
Iron is one of the most abundant elements in the body and is essential for performing many biological functions.
Iron plays a critical role in oxygen transport, as it is necessary for the formation of haemoglobin, the oxygen transport protein critical for aerobic capacity. It is also necessary for the optimal function of many oxidative enzymes that affect intracellular metabolism.
There is evidence to suggest that exercise affects iron levels and vice versa, a low iron level could negatively affect physical performance.
Women ages 19 to 50 have a recommended daily allowance of iron of 18 mg/day. In sportswomen, these recommendations can increase to 30 mg/day, because of the losses of this mineral through sweating, the micro-injuries generated by physical exercise, and the elimination of blood in the intestine (especially in women who practise sports background).
What are the dietary sources of iron? Of animal origin: red meat (veal, horse or beef), egg yolk, shellfish, poultry and offal products (kidney, liver …). Of plant origin: whole grains, legumes, dark green leafy vegetables (turnip greens, cabbages, beet greens, spinach…), nuts, dried fruit, seeds (especially pumpkin) and products fortified like some breakfast cereals or some vegetable drinks. Animal iron is absorbed much more than vegetable iron.
A trick! Whenever you eat foods rich in vegetable iron, accompany them with foods rich in Vitamin C (fruit: kiwi, pineapple, orange, tangerine, strawberries… and raw vegetables).
Another trick! Try not to drink cocoa, wine, tea or coffee after a meal rich in iron, the tannins in these foods make it difficult to absorb iron.
The vegetarian diet poorly planned, sports background, and menstruation are risk factors for women to develop iron deficiency (iron deficiency anaemia), so if you are in one or more of these groups realised the iron you consume.
Calcium is the most abundant mineral in the body. Approximately 1% of the body’s calcium will be used in muscle contraction, while 99% is found in our bones and teeth. That is, calcium is one of the main minerals responsible for maintaining bone density. In adulthood, the strength of the bones begins to be lost, a process that is accelerated in women by reducing the levels of oestrogens (a hormone that takes part in bone metabolism). Athletes with heavy training loads and menstrual irregularities (these translate into low oestrogen levels) should pay special attention to calcium intake, as bone wear could cause “stress fractures”.
Calcium requirements in adults are 800-1000 mg/day, which can be increased to 1,500 mg/day in sportswomen since physical activity increases bone mass and mineral content.
For all this, your diet should include foods rich in Calcium, such as dairy products (milk, cheese, yoghurt), Calcium-enriched vegetable drinks, seafood, oily fish, nuts, seeds, legumes, enriched whole grains, some vegetables (broccoli, cabbage, kale, collard greens, leeks).
Note! Don’t forget about vitamin D, as this fat-soluble vitamin helps to fix calcium in the bones. Their food sources are fish, eggs, whole dairy products, enriched vegetable drinks, butter. But above all, it ensures correct exposure to the sun without sun protection, for at least 20 minutes 3 times a week.
Folic Acid (vitamin B9) is a fundamental nutrient for the body, especially since it is used in the body to: collaborate in muscle regeneration (creation of red blood cells) produce and maintain the structure of DNA, and also to prevent the appearance of diseases such as anaemia.
In athletes, folic acid plays a very important role in repairing and growing muscle cells, resulting in an important component to achieving optimal sports performance. In addition, it can act as a powerful antioxidant agent, and combat the damage caused by free radicals that are generated in the body of an athlete.
The recommended daily amount of folic acid is 200 mcg, being for athletes a dose that can range between 800 and 1200 mcg per day. Folic acid cannot be synthesised in the body, so you must get it through dietary sources. What are these sources? Green leafy vegetables, legumes, nuts, sunflower seeds, avocado, fortified cereals, egg yolk, white and bluefish, seafood and offal products.
Note! Because it is a water-soluble vitamin and can be destroyed during cooking, folic acid has low levels in many people, thus affecting the body and athletic performance. Therefore, try to consume raw vegetables daily, use quick-cooking such as steam (little loss of nutrients) or use the cooking water to make a recipe such as a puree.
IMPORTANT! Although the requirements of some minerals and vitamins are increased in sportswomen, having also increased energy needs, this facilitates meeting the requirements. That is, by eating more, it will also contain more macro and micronutrients, as long as it is a well-planned intake.
How to avoid the triad of the athlete?
It exposes some girls who do sports or physical exercise intensely to suffering a disorder known as “athlete’s triad” (also known as “athlete’s triad”). This situation affects women and is a combination of the following three disorders: alterations in eating behaviour, amenorrhoea, and osteoporosis. An athlete can have one, two or all three components of the triad. Without treatment and depending on what age it occurs, the consequences can be very serious and irreversible, such as loss of bone strength, damage to organs because of lack of nutrients, excessive weight loss, absence or irregularity in menstruation, fatigue, stress fractures …
To avoid having this problem, it is very important to eat a sufficient amount of calories to meet the energy demands your sports practice implies. Following a balanced diet, having healthy eating habits, and exercising moderately is key. Remember that proper nutrition optimises physical performance and contributes to improving sports results. Never eating a diet that is too restrictive can benefit you. Low energy availability negatively influences the athlete’s bone health, either directly or because of a hormonal imbalance in a situation of amenorrhoea.
In the case of suffering from an eating disorder, we should treat this pathology with a multidisciplinary team made up of doctors, psychologists/psychiatrists, dieticians-nutritionists, coaches, physical trainers and the athlete’s family. It bases an appropriate strategy on the education of athletes and all the surrounding people within the sports field.