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The training process is the key to success. Most athletes put focus on their training process and they essentially plan every minute of their season. However, athletes often forget that optimal nutrition is also an important aspect which determines their health and performance.  

What you eat actually influences your training process together with regeneration and is an important factor of your perfomance.

The advice for optimal nutrition may be especially relevant for women. Women’s body composition and hormonal milieu together affect both energy and fluid needs. These parameters also vary within the month according to the phase of menstrual cycle. The menstrual cycle is characterized by fluctuations in hormones (estrogen and progesterone) which influence metabolism as well as fluid retention and can play a major role in performance timing (see the article about the menstrual cycle). 

It is normal that you do not feel the same everyday and you crave different things.

A lot of professional woman athletes confirm their period has an impact on their mood, focus, strength, and body composition, and thus on their performance. Many woman have had thoughts such as: “I am so hungry.” “I am craving chocolate.” “I am tired.” “I am moody.”. There are some women who feel this way once a month. One question is, what is the reason behind these feelings? The answer is linked to hormones. They do influence our mood, physical dispositions, hunger and can a play major role in our performance.

“You can help yourself with the right diet though!”


ADEQUATE CALORIC INTAKE - “How much should I eat?”

EI (Energy intake) = EEE (‘’Energy expenditure in exercise’’) – FFM (fat free mass). 

Energy intake is your total caloric intake. Energy expenditure in exercise is the amount of energy required to exercise. Fat free mass includes all lean mass, including muscles, bones, and water mass.

Physical activity as defined by duration and intensity correlates to the energy expenditure during exercise. Any exercise session: strength, endurance, or technique increases our energy demand. If the energy expenditure is higher than the energy intake, we experience weight loss and vice versa; although keeping track of this is difficult as our energy intake will also affect our energy demand at rest. We can lose or gain muscle as well as we can lose or gain fat. 

Being as light as possible became an unhealthy trend among women. It might be defined by the fashion industry, just look all these super models.

But why do we follow this trend in sport? 

Weight loss might increase performance for a short period of time, especially in endurance sports, but it is the primary cause many problems in the long run. 

In terms of performance the energy deficiency affects:

  • bone health
  • metabolism 
  • gastrointestinal health and immunity
  • cardiovascular system
  • endocrine system and menstrual cycle
  • psychological state

In consequence these factors increase the risk of injury, and influence the training response:

  • concentration 
  • muscular strength
  • endurance
  • glycogen metabolism
  • coordination
  • mindset


Energy intake level ( how many calories women should eat to avoid any body composition changes) is defined in calories (kCal). Of course, all women athletes are different. 

And you are different too.

There are many aspects that influence our caloric needs, such as our body composition, metabolism, training process, and free time activities. 

However, general recommendations are provided: 


“Do you want to stay healthy?”

Then caloric intake should not be less than 30kCal/kg of FFM/day. 


“Do you want to maintain body weight and skills?”

45 kCal/kg of FFM/day is recommended for maintaining body weight and skill development. 


“Do you want to gain muscle weight and improve skills?”

More than 45 kCal/kg of FFM/day is defined as sufficient for muscle growth. 


Low energy availability leads to a loss of weight together with hormonal changes that negatively affect the menstrual cycle and a woman’s metabolism. 


DIET- “What should I actually eat?”

How should your optimal diet look?


Balanced diet

The important factor in nutrition is regularity. It does not really matter if you are eating 3 or 5 times a day, as long as you maintain your caloric intake. 

A balanced diet consists of macronutrients such as carbohydrates, proteins, fats and micronutrients so that you can stay healthy and functional. 


MACRONUTRIENTS- “make your food rich and balanced”

Once caloric intake is defined, the amount of macronutrients including proteins, carbohydrates and fats can be set according to individual needs. 

"But what are my actual needs?”

Every woman is different- different tastes, different preferences, different training plan, different phase in menstrual cycle, different daily routine. Therefore, you should consider all these parameters when designing the nutrition plan.



We all like them, right?

“They are sweet. But are we talking about the same carbohydrates? It might be a little bit tricky.”

Carbohydrates are found in a wide array of both “responsible” and “irresponsible” food. The type of carbohydrate in our diet is way more important than the specific amount of calories which come from them. We can put carbohydrates in 3 categories: sugars- simple carbs, starches and fiber- complex carbs.

“Not only sugars!”

Carbohydrates are the main source of energy for our body and should represent 60% of your energy intake (1). Complex carbohydrates are broken down into glucose which can be used as an energy source or can be stored as glycogen and used later. For this reason, carbohydrates represent a necessary part of your diet, especially in sport. 

Sugars,=simple carbohydrates are found in sweets, bars, sweetened drinks, but also fruits. They are mostly digested fast and represent “immediate” source of energy. Therefore, they can not alone replace a meal.

Complex carbohydrates can be found in cereal, pasta, bread, potatoes etc. They take more time to be broken down and are used as energy source in longer terms.

However the time of digestion is relevant to the glycemic index (GI) which shows how quickly the food affects blood sugar and is digested. Lower the GI is, less it will raise your blood glucose. For better imagination, an apple has for example GI= 36, whether whole wheat bread has 74.

Fibers is found in cereals, fruits, vegetables, beans, etc. It is a non-digested carbohydrate. That means that your body can not break it down and it provides a feeling of fullness. It is important for your stomach and gut health.



Talking about proteins, we might think about muscle gain. 

And that I correct but it is not the only thing…

Proteins help to gain and maintain muscle but it is not their only function. Proteins are also important for tissue regeneration. They help to generate muscle tissues and cells, increasing the training response, and enhancing performance. The timing, type and amount of protein have an impact on post-exercise regeneration. The amount of protein recommended is 1.2 - 2 g/kg/day.

Female athletes are at a higher risk not meeting these requirements, especially these who want to lose weight or who are vegans. (2)

You can find proteins in meat, yoghurt, soya, legumes, beans etc.

 And what about timing? Are there any particular moments that matter?

You might have seen these body builders in a gym shaking their protein drinks right after their session. Why that?

Protein timing seems more and more less important once you reach the recommended amount every day.

Although, further research is needed in this area, there are some studies which suggest that having your protein before or 0-2 hour after your workout might increase the protein synthesis in your muscle and enhance muscle growth and recovery. While exercising in the afternoon, taking your protein before a sleep could help as well. 

Regarding endurance training, there are early studies suggesting that protein together with carbohydrate before and during endurance workout might prevent from muscle soreness and increase performance. 

There is not statistic evidence about “magic time windows” but you can definitely give a go to any of these tips. 

And how should I distribute all this protein within a day?

Again the most important thing is actually reaching the recommended dose. 

But if you really want to do your best and go into details, to maximize the muscle protein synthesis you can spread your protein amount into pulses (20-25 g) every 3 hours.

Proteins also enhance your immunity since they work as base for antibodies.



Fats are as important as proteins and carbohydrates. They should represent 20 - 35 % of our diet. Only 6% of the latter should be represented by saturated and trans- fats. These fats are mainly found in animal based products and dairy products. In high doses they are harder to utilize, have been shown to negatively impact the richness and diversity of the gut microbiome, and have implications in cardiovascular disease.

“That does not mean that you should not eat meat or yoghurt! They do have some health benefits too.”

Unsaturated fats are mainly found in plant-based diets and they have positive effects on health and performance. They are a source of long lasting energy.

A low-fat diet is not recommended for female athletes as it can affect nutrient and energy intake, performance and general health. High fat food with health benefits are avocados, whole eggs, nuts, chia seeds, and fish.


Omega 3 and Omega 6

These essential fatty acids are an important component of cell membranes and are involved in regulating blood pressure and inflammatory responses. Omega-3 help to reduce inflammation whereas omega-6 tend to promote inflammation. 

These fatty acids cannot be synthesised by the body.

So you need to get them ‘ready-made’ from the diet.

Omega-6 occurs for example in sunflower oil, seeds, coconut oil, and soy beans. Natural sources of omega-3 are fish and nuts. It can be quite hard to get the recommended doses from your daily diet though, therefore supplementation of these fatty acids is recommended.

The recommended ratio of omega-6 to omega-3 is 4:1.

Which means that for one gram of omega-3 you need to eat 4 grams of omega-6.

However, nowadays, studies has shown that due to higher consumption of industrual food rich in omega-6 content can be up to 60:1. 

Some studies (13) has shown that omega- 3 supplementation may have a positive effect on endurance performance, muscle soreness, recovery process and immunity. 


MICRONUTRIENTS- “microthings make the difference”

 Malnutrition correlates to micronutrient deficiency which is caused by low availability of particular micronutrients in the diet, malabsorption, or inhibition. In these cases, micronutrients would need to be supplemented.

Active women have higher needs of micronutrients. Female athletes mostly experience iron, calcium and vitamin D deficiencies. Other micronutrients can be supplemented according to individual needs. 

Micronutrient deficiency can be the starter of long term problems



24 - 47 % women experience iron deficiency (3). The reasons are various. In most cases, it is due to inadequate caloric intake. Active women are at higher risk than non-active women. 

Why is that? 

Firstly, the cells of active women produce more energy. They also have more red blood cells to carry oxygen and these cells are broken down more quickly. Secondly, iron is lost through sweat. 

Loss of iron can affect bone health, metabolism, and shift ATP production to rely more heavily on the less effective anaerobic pathways.

The recommended dose of iron is 22 mg/day (4) for active women. While experiencing iron deficiency the dose of approximately 100 mg/day together with vitamin C (which increases absorption) for 8 days is recommended (5). 

Iron can be found in meat, legumes, nuts, dry fruit.



Calcium plays an important role in bone health. A dose of 1500 mg/day (6) is recommended for female athletes with high risk of calcium deficiency. However, the gut can absorb only 500 g at one time, so the daily dose should be spread out throughout the day.  

Calcium is present in yoghurt, cheese, nuts, and milk.



Vitamin D is important for maintaining bone and skeletal muscle health, as well as to prevent injuries. Vitamin D deficiency is higher during winter because sunlight increases vitamin D synthesis. Vitamin D3 enhances your immunity system and help you to stay healthy. 

If you supplement vitamin it is good to eat it together with fat since it is a fat soluble vitamin, 

The recommended dose of vitamin D supplementation is 1000–2000 IU (7). Vitamin D needs are very hard to get from the diet, so sun exposure is necessary to help its sythesis.



An athletes main responsibility throughout the season is to stay healthy and avoid training time loss due to disease. Vitamin C has an important role in the immune system and it also helps with iron absorption and collagen development.  

Vitamin C deficiency can be linked to low levels of red blood cells and can help with cell.

The recommended dose is 75 mg per day for women (8). 

Vitamin C occurs in lemons, oranges, papayas, pineapples, and other fruits.


HYDRATION- “How much should I drink?”

It is a very important part of training to stay hydrated. Athletic women should drink 2 - 3 liters per day. 

You can stay alive without food up to one week, whereas 3 days without liquid intake are life dangerous!

It is proven that only 2% water loss out of our body weight has a negative impact on our performance. Insufficient fluid intake decreases the blood’s ability to transport oxygen and metabolites. This leads the metabolism into acidosis, where performance decreases and regeneration slows down. (9)

About 60% of your body is made of water.

It is very important to spread out our fluid intake throughout the day. It helps to regulate body temperature, maintain homeostasis, and maintain kidney function. Immediate consumption of too much liquid can be dangerous. 

The main part of our daily fluid intake should be represented by water. However, we lose minerals such as sodium and potassium (which are important for internal homeostasis in our body) through sweating during physical activity. Therefore, sport drink consumption with these minerals should be considered to fulfill electrolytes throughout the workout.

Regarding the amount of fluid, minerals, and sugars we distinguish 

  1. Hypotonic drinks- have lower concentration of minerals, sugars and fluids than blood.

When? Pre- hydration, during longer workouts, in hot weather

  1. Hypertonic drinks- have higher concentration of minerals, sugars and fluids than blood.

When? After workouts

  1. Isotonic drinks- have similar concentration of minerals, sugars and fluids than blood.

When? Shorter and high-intensity workouts



Eating disorders, mostly caused by low energy availability, represent a common problem among women athletes. Estimates of the prevalence of eating disorders are variable at 6-45% (10). However, a recent study showed the risk at 47% of investigated women (11).

From the caloric point of view, energy intake should not be less than 30kCal/kg FFM/day in order to avoid any body composition changes. Level of 45 kCal/kg FFM/day is recommended for maintenance of body weight and skill development. More then 45 kCal/kg FFM/day is defined as sufficient for muscle growth. 

Low energy availability leads to loss of weight together with hormonal changes which negatively affect menstrual cycle and woman’s metabolism.


IMMUNITY: Stay ready

You all have probably experienced this situation: you train hard and then suddenly the day of your competition you get sick. Staying healthy is one of the most important responsibilities and you have as an athlete though. And right nutrition can help you.


  1. Caloric intake: Sufficient caloric intake enhance your immunity system. Your body need enough energy to keep itself healthy. It is known that athletes who are in caloric deficiency for longer time are susceptible to diseases . 

2. Proteins are main base for antibodies and help your body to maintain main body functions. 

3. Vitamins and minerals: Vitamin C, Vitamin D3, probiotics

4. Veggies and fruits which are full of micronutrients and minerals and moreover contain fiber which works as a probiotic! 

    • You remember this indigestible carbohydrate?

5. Sleep: the best regeneration. 

    • You might think that it has nothing to do with nutrition. But of course it does. 
    • Quality of your sleep is very important for you body and immunity system.
    • And caffeine is that intruder we are talking about. You should not get a coffee or another drink which contains caffeine at least 6 hours before you go to the bed.

6. Stress: the time our body is facing stress is when it is very fragile.





Despite the wide choice of food nowadays, sport supplements are a popular and regular part of the training process.

We discussed the right type of balanced diet earlier, including specific amounts of both macronutrient and micronutrient demands. However, is it possible to get all these particular nutrients from a daily diet? 

We can find most of these nutrients in daily food but sometimes it can be really hard to reach the prescribed amount, especially in some seasons of the year. Nutritional supplementation can not replace a balanced diet but it is considered an important addition to a balanced diet.

Thus, mineral and vitamin supplementation is strongly recommended, especially for professional athletes whose energy demands are even higher (see micronutrients). It is very important to point out that demands are strictly individual. However, the more we train, the more at risk we are of deficiencies.

In terms of the training process, we want to enhance performance, regeneration, immunity, and energy for workouts. Nutritional supplements seem to be a good option to help accomplish this.



Proteins are a popular supplement.

Muscles, organs and hormones consist of proteins. Muscle cells, tendons and ligaments are maintained, regenerated and enhanced using protein. Proteins are one of the main components of lean body mass. Studies has shown that protein supplementation enhances muscle mass development and hormonal regulation. It also enhances post-workout regeneration. 


“That explains all these body builders shaking their shakers with protein right after their workout- correct?”



One of the most studied supplements ever. 

Creatine is naturally occurring amino acid which through biological pathways enhances maximal muscle contraction and postpone its fatigue. It also increases muscle mass, strength, power, and sprint performance, participate on regeneration process. Supplementing creatine is recommended together with carbohydrates (like a fruit juice) since these help absorption. 

However, some studies suggest that creatine supplementation can be inhibited by caffeine. 

“So, better not taking coffee together with your creatine dose. Fruit juice is a better option!”



“Coffee is running the world.” 

It has became a social thing and part of daily lifestyle. For many people caffeine means coffee. 

And that is correct. 

“In society 14 tis coffee which might be linked to caffeine the most.” 

However, caffeine can be naturally found in tea, cacao, guarana leaves, some fruits, or beans. Caffeine works as a stimulant for our nervous system and enhances alertness and energy level.

400 mg of caffeine per day is considered as safe. 

“Imagine that one espresso contains around 65 mg of caffeine, 1 ounce of dark chocolate around 20 mg and one cup of black tea is around 45 mg. 

Caffeine improves performance in doses from 3 to 16 g/kg/day. Caffeine is absorbed around 45 minutes after consumption and the peak appears from 15 min - 2 hours. The usual dose is consumed 60 min before performance. Caffeine supplementation enhances muscular endurance, movement velocity, and muscular strength, as well as a wide range of aerobic and anaerobic sport-specific actions. Additionally, caffeine has been proven to improve cognitive function, including attention and vigilance



“Have you heard about the magical beetroot juice?”

All credit can actually go to the nitrates that beetroot contains. Nitrates have been proven to reduce oxygen consumption of total muscle work and improve muscle contraction. They play a major role in improving time to exhaustion, total power output and distance. They are used to enhance both endurance and sprint performance. The amount of recommended dose vary throughout the studies as 300 - 1000 mg, 2- 3 hours prior. (12) 

Written by Andrea Duchoňová


Reference list:

  1. Ryan-Harshman, M., & Aldoori, W. (2006). New dietary reference intakes for macronutrients and fibre. Canadian family physician Medecin de famille canadien, 52(2), 177–179.
  2. Carbone, J. W., & Pasiakos, S. M. (2019). Dietary Protein and Muscle Mass: Translating Science to Application and Health Benefit. Nutrients, 11(5), 1136. https://doi.org/10.3390/nu11051136
  3. Sim M, Garvican-Lewis LA, Cox GR, Govus A, McKay AKA, Stellingwerff T, et al. Iron considerhations for the athlete: a narrative review. Eur J Appl Physiol. 2019;119(7):1463–1478. doi: 10.1007/s00421-019-04157-y.
  4. Mountjoy M, Sundgot-Borgen J, Burke L, Carter S, Constantini N, Lebrun C, et al. The IOC consensus statement: beyond the Female athlete triad-relative energy deficiency in sport (RED-S) Br J Sports Med. 2014;48(7):491–497. doi: 10.1136/bjsports-2014-093502.
  5. Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: nutrition and athletic performance. J Acad Nutr Diet. 2016;116(3):501–528. doi: 10.1016/j.jand.2015.12.006. 
  6. Del Valle HB, Yaktine AL, Taylor CL, Ross AC.  Dietary reference intakes for calcium and vitamin D. National Academies Press; 2011
  7. Del Valle HB, Yaktine AL, Taylor CL, Ross AC.  Dietary reference intakes for calcium and vitamin D. National Academies Press; 2011
  8. Doseděl, M., Jirkovský, E., Macáková, K., Krčmová, L. K., Javorská, L., Pourová, J., Mercolini, L., Remião, F., Nováková, L., Mladěnka, P., & On Behalf Of The Oemonom (2021). Vitamin C-Sources, Physiological Role, Kinetics, Deficiency, Use, Toxicity, and Determination. Nutrients, 13(2), 615. https://doi.org/10.3390/nu13020615
  9. Belval, L. N., Hosokawa, Y., Casa, D. J., Adams, W. M., Armstrong, L. E., Baker, L. B., Burke, L., Cheuvront, S., Chiampas, G., González-Alonso, J., Huggins, R. A., Kavouras, S. A., Lee, E. C., McDermott, B. P., Miller, K., Schlader, Z., Sims, S., Stearns, R. L., Troyanos, C., & Wingo, J. (2019). Practical Hydration Solutions for Sports. Nutrients, 11(7), 1550. https://doi.org/10.3390/nu11071550
  10. Rowland T. Iron deficiency in athletes: an update. Am J Lifestyle Med. 2012;6(4):319–327. doi: 10.1177/1559827611431541.
  11. Committee on Mineral Requirements for Cognitive and Physical Performance of Military Personnel, Committee on Military Nutrition Research, Food and Nutrition Board, Institute of Medicine (IOM). Mineral requirements for military personnel: levels needed for cognitive and physical performance during garrison training. Washington (DC): National Academies Press; 2006.
  12. Daiber, A., & Münzel, T. (2015). Organic Nitrate Therapy, Nitrate Tolerance, and Nitrate-Induced Endothelial Dysfunction: Emphasis on Redox Biology and Oxidative Stress. Antioxidants & redox signaling, 23(11), 899–942. https://doi.org/10.1089/ars.2015.6376

Thielecke, F., & Blannin, A. (2020). Omega-3 Fatty Acids for Sport Performance-Are They Equally Beneficial for Athletes and Amateurs? A Narrative Review. Nutrients, 12(12), 3712. https://doi.org/10.3390/nu12123712

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