Version classiqueVersion mobile

Nutrition and Performance in Sport

 | 
Christophe Hausswirth

Chapter 4. Nutrition and specific sport populations

Topic 15. Specificity of the woman

Christophe Hausswirth, Amélie Fosse, Axel Heulin, Yann Le Meur, Véronique Rousseau, Eve Tiollier et École Lenôtre

Texte intégral

Questions and answers

Key points
In high-level female athletes, the daily calorie intake is often insufficient, especially in those participating in sports where a thin body format is the norm.
For a female athlete consuming around 2000 Cal per day, it is impossible to significantly increase glycogen stores simply by increasing the proportion of carbohydrate in the diet. For this population, a lipid intake corresponding to about 30% of the total energy intake is recommended.
To ensure structural recovery, it is recommended that female athletes have a higher daily protein intake than that required for the general population (1.2 to 1.4 g.kg−1 of body weight as opposed to 0.8 g.kg−1 of body weight).
It is particularly relevant to draw female athletes’ attention to the necessity to regularly consume iron-rich foods.

For female athletes wishing to maintain a thin shape, what dietary strategy should be proposed?

1The energy balance (difference between daily calorie intake and daily energy expenditure) is something female athletes must take into account. Indeed, these athletes are often concerned about their physical appearance and may be subjected to social pressure to maintain a low fat mass percentage. Nevertheless, female athletes should maintain a positive energy balance to ensure energy storage and muscle regeneration. This approach will make it possible to support the training workload and progress in the long term. Despite these recommendations, epidemiological studies show that daily calorie intake is very often inadequate in high-level female athletes, especially in those practising sports where a thin shape is the norm. Thus, some of these athletes have a negative energy balance almost persistently throughout the day. Maintaining a balance between energy intake and expenditure through appropriate nutritional recovery strategies is not only important in endurance disciplines, but in all sporting activities involving daily training, or several daily training sessions. Thus, an inadequate energy intake is worrying as it has negative consequences on various bodily functions, leading to decreased bone mineral density (in the long term, this is associated with an increase in the risks of stress fractures and osteoporosis), decreased cognitive performances (which is especially problematic in sports where precision is a key element), decreased immune status, amenorrhea and, if it persists long term, increased cardiovascular risks.

2A negative energy balance results in chronic fatigue, decreased alertness, sleep disorders and an increased use of non-dietary proteins, which can jeopardize muscle recovery. Any of these symptoms should alert the athlete’s entourage to a potential problem with undernutrition, which could accelerate the appearance of overload. As two-thirds of female athletes say they want to lose weight, and to do this they limit their daily calorie intake, it appears important to inform them of the importance of managing their diet correctly. Indeed, restricting calorie intake does not always lead to weight loss (because it can also decrease resting metabolism), but it does generally perturb the menstrual cycle. In general, most female athletes should consume 2300 to 2500 Cal.d−1 to maintain their body mass. If they practise endurance sports such as marathon or triathlon, energy needs can increase to 4000 Cal.d−1. In a high-level female athlete, a diet for weight-loss purposes should be undertaken over a prolonged period and in line with a certain number of key recommendations (see Practical recommendations, p. 408).

Do female athletes have any specific nutritional requirements during post-exercise recovery?

3During exercise, women use their carbohydrate stores less than men, they also synthesize less glycogen than men in response to a given carbohydrate intake. A female athlete consuming ± 2000 calories per day cannot significantly increase her glycogen storage only by increasing the proportion of carbohydrate in her diet. These athletes must increase their energy intake by 30% for four days to ensure an intake exceeding 8 g.kg−1 body weight. In practise, this is not generally applied or easy to accept in athletes whose weight is frequently monitored. In addition, focusing exclusively on carbohydrates is likely to lead to deficiencies in essential fatty acids and proteins, and to jeopardize the nitrogen balance necessary to maintain appropriate androgen levels. In this context, several authors recommend a lipid intake corresponding to 30% of the total energy intake. Thus, female athletes should consume vegetable oils, nuts and “oily” fish (cold water fish), like salmon or tuna, regularly. They should also be informed of the various roles played by lipids in the body (immune system, cell membrane components, transport of some vitamins).

4For proteins, it is recommended that daily intake be greater than that recommended for the general population (1.2 to 1.4 g.kg−1 of body weight versus 0.8 g.kg−1 of body weight). This higher intake will help to ensure structural recovery. Despite these recommendations, several studies investigating female athletes indicate that their protein intake is very often in the lower end of the range, or even below, particularly in athletes who have menstrual problems. For women specializing in strength sports, a protein intake of up to 1.4 to 1.8 g.kg−1 is recommended, this type of activity generates significant muscle damage; proteins are therefore necessary both for protein synthesis and to maintain, or gain, muscle mass. Because protein is often contained in foods which also contain iron, the risk of anaemia, to which women are particularly exposed, may be more limited in this population. Female athletes should be informed of the advantages of consuming animal proteins, which are excellent sources of vitamins B12 and D, thiamine, riboflavin, calcium, phosphorus, iron and zinc.

How can the iron losses linked to menstruation be compensated through diet?

5During the menstrual cycle, iron losses vary between about 5 and 45 mg per day. In female athletes, these amounts can be increased due to sweating or haemoglobin losses in urine. This excretion is linked to red blood cells being destroyed as body temperature increases during exercise. Repeated shocks, due to the feet pounding on the ground, are also likely to increase iron losses caused by the destruction of red blood cells in the soles of the feet and in the gastrointestinal tract. These data must be seriously considered as severe iron deficiency, known as “iron deficiency anaemia” (detected by a blood test), can lead to chronic fatigue, asthenia and a reduced capacity to perform exercise, even at a low intensity. This type of deficiency is readily diagnosed by regular blood analyses. All of these data explain why female athletes must be careful to consume an appropriate amount of iron-rich food every day, particularly foods rich in “haematinic” iron, which is assimilated four to five times better than “non-haematinic” iron. These considerations should be taken into account because most scientific studies indicate that female athletes have an inadequate iron intake.

Why should particular attention be paid to calcium intake in female athletes?

6Most physical activities exert strong pressure on the skeletal system which increases the turnover of bone cells. As the mechanisms of osteogenesis and, therefore, of bone recovery depend closely on calcium intake, it is essential that athletes have an adequate intake of this element. The recommended daily dose is 1300 mg for young women aged between 9 and 18 and 1000 mg for adult women (aged 19 to 50). However, several studies show that even though calcium intake is within the range of 500 to 1623 mg in most female athletes, many of them have an intake below 1000 mg.d−1. In activities where a thin shape is the norm, athletes often severely restrict their daily calcium intake. This level of intake represents a risk to their bone health and increases the risks of stress fractures. Thus, it seems necessary to ensure adequate calcium intake to favour bone regeneration in the medium-term to ensure the development and maintenance of bone health in the long term.

7Nevertheless, calcium intake is not the only parameter affecting optimal calcium absorption and bone health; vitamin D also plays a role. Vitamin D status is often low in athletes living in northern countries, or those who train mostly indoors. This low status may be problematic as vitamin D is required to maintain good bone health. Athletes must therefore

8balance this deficiency through dietary adaptations or the use of light therapy. Other factors contributing to bone health are an appropriate protein intake and sufficient energy intake. The combination of all these elements in the diet, in the short term, will prevent the risk of stress fractures and, in the long term, will help avoid problems due to osteoporosis.

Why should particular attention be focused on vitamin B intake in female athletes?

9Athletes who have an inadequate daily energy intake also frequently have a vitamin B deficiency. This deficiency can be problematic because micronutrients play an essential role in energy production, haemoglobin synthesis, immune system maintenance and repair of muscle damage caused by training.

■ Practical recommendations

1. How to deal with weight

10– Identify realistically the weight at which you would feel good about yourself and could also perform well. To do this, the following questions may help: what is the maximal weight I consider acceptable? What weight can I maintain without being constantly on a diet? At what weight can I perform well? How much of my time do I spend thinking about my weight and shape?

11– Focus less on the scales and more on healthy eating habits, especially the choice of appropriate food and keeping to a regular meal schedule.

12– During a weight-loss diet, measure your progress while ensuring that your level of performance is good, that you do not encounter more frequent injuries, that your menstrual cycle is normal and that you feel well.

13– Start a diet through your own choice and not because someone else says you should.

2. How to eat

14– Do not establish untenable food rules. Make your objectives flexible and accessible. Keep in mind that all food types can be part of a balanced diet, but that some of them should be consumed in smaller amounts (chocolate, desserts or fatty foods, for example). Avoid making lists of “good” and “bad” foods.

15– If you need to reduce your calorie intake to lose weight, start by adhering to the following principles: avoid foods rich in fat, reduce your intake of foods with a high energy value and implement strategies to avoid eating when you are not hungry.

16– Before starting a diet, identify your weak points and think about how you can deal with them efficiently.

17– Do not skip any meals and make sure you do not remain hungry for too long.

18– Have breakfast to avoid eating too much at lunch (for instance).

19– Keep in mind that limiting fat intake is only associated with weight loss if a positive energy balance is maintained.

20– Increase your consumption of cereals, seeds, vegetables and soya, with at least five portions per day.

21– Drink throughout the day, both during training and at other times. Do not use dehydration to artificially lose weight.

22– Make sure you eat enough fibre (more than 25 g per day).

Practical applications

Image 10000000000004000000010846B7699D.jpg

1. Minimizing the risk of iron deficiency

23Female athletes have greater requirements for some micronutrients (the number of + indicates a higher or lower amount of micronutrients).

Iron

Image 10000000000000230000001F5B2871AD.jpgIron deficiency results in significant fatigue.

Image 10000000000003FE0000022E54E41E68.jpg

Calcium

Image 10000000000000230000001F5B2871AD.jpgCalcium deficiency increases the risk of stress fracture

Image 1000000000000411000002C692A1B367.jpg

Vitamin D

Image 10000000000000230000001F5B2871AD.jpgVitamin D deficiency results in muscle pains and increases the risk of stress fractures

Image 10000000000003FA000001ABD6573E6D.jpg

Magnesium

Image 10000000000000230000001F5B2871AD.jpgMagnesium deficiency results in muscle pains and mood and sleep disorders

Image 10000000000003FC000002FCF867C91F.jpg

2. General recommendations

Maintain a good energy balance...

Image 1000000000000111000000C1821F843C.jpg

…and vary your food

Image 10000000000000230000001F5B2871AD.jpgTo meet your vitamin and mineral needs, you must consume more than 2000 calories per day

24 Adapt your starch and vegetable intake to meet the needs of your physical activity each day

Image 10000000000003FC000001120C0799C1.jpg

25 Before the training session

Image 10000000000003F800000181232B47DC.jpg

3. If you need to lose weight

26(See Fact sheet No. 20 Reducing fat mass, p. 469)

27 Prepare to lose weight

28 To better prepare for losing weight, ask a nutritional expert

29 Identify your ideal weight based on fat mass percentage, and not on the weight on the scales

30 Depending on your activities and training sessions, adopt an appropriate food and hydration strategy (See Factsheet No. 10 Hydration, p. 342)

31 Identify your weak points and think about strategies which could help you to deal with them effectively

32 Start your weight loss well

33 Do not focus too much on the scales; focus more on healthy eating habits

Image 10000000000000230000001F5B2871AD.jpgWeigh yourself at most once a week, in the same conditions. For example: in the morning before eating or drinking, in the middle of the week

34 Avoid skipping meals and heed hunger pangs

35 Drink throughout the day

Image 10000000000000230000001F5B2871AD.jpgDehydration only leads to artificial weight loss. It considerably increases the risk of injury

36 While reducing your weight, make sure you...

37 Maintain your performance level

38 Are not more prone to musculoskeletal pains

39 Continue to menstruate regularly

40 Sleep well

Image 10000000000000230000001F5B2871AD.jpgIf any alarm signals appear, consult a doctor rapidly

Recipe

Chicken liver salad, baba ghanoush

Image 100000000000011B0000017B24A08CB4.jpg

Image 10000000000001FA0000020005ED917C.jpg

Photo credit: Thibaut Ruggeri.

41Serves 2

42Preparation time: 20 minutes

43Cooking time: 30 minutes

Difficulty: Image 10000000000000290000001FAF3FB94E.jpg

44Ingredients

45 200 g cooked chicken liver

46 Salt, pepper

47 5 g mixed salad

48 20 g raspberry vinegar (or pomegranate molasses)

49 100 g Lebanese baba ghanoush

50 2 g chopped parsley

51 2 g chopped chives

52 20 g red pomegranate seeds

53 30 g toasted brown bread

54 10 g olive oil

55 20 g low-fat lemon dressing

56Season the chicken livers and fry rapidly in olive oil.

57Deglaze the pan with the raspberry vinegar.

58Dress the salad with the low-fat lemon dressing, and place it in the centre of the plate.

59Top with the warm chicken livers.

60Shape three portions of baba ghanoush with spoons, and place around the sides of the plate.

61Sprinkle with pomegranate seeds and chopped herbe. Serve with toast.

62Low-fat lemon dressing

63 15 ml lemon juice

64 25 ml water

65 15 g rapeseed oil

66 15 g yellow mustard

67 Salt, pepper

68Mix all the ingredients to form an emulsion.

69Lebanese baba ghanoush

70 500 g aubergines

71 1 peeled garlic clove

72 10 g salt

73 Juice of half a lemon

74 150 g organic tahini

75Prick the aubergines with the tipe of a knife and grill over a gas ring or in the oven (grill position).

76Peel and drain in a colander.

77Chop finely, and add the crushed garlic.

78Add the salt, lemon juice and tahini.

79Chef’s note

80Thanks to the chicken livers, this dish is rich in iron: it covers 75% of the Dietary Reference Intake for women. It is also very rich in vitamin B.

81As this dish does not contain much carbohydrate, it should be powed with bread. A vegetable-based starter or dessert (raw vegetables, fruit) with the vitamin C they provide, will promote absorption of the iron.

82It would also be wise to add a dairy product to the meal as a source of calcium.

83Nutritional analysis per person

Energy (Cal)

Carbs (g)

377

21

Lipids (g)

Protein (g)

16

30

Auteurs

© INSEP-Éditions, 2015

Conditions d’utilisation : http://www.openedition.org/6540

Rechercher dans OpenEdition Search

Vous allez être redirigé vers OpenEdition Search