11/02/2025
Female Health

It is essential that athletes fuel optimally to support the physical demands of their training and competition, whilst aiding their adaptation to training. Further consideration should be given to supporting health throughout the year and the growth and development needs of young athletes. 

For a female athlete, there are further nutritional considerations that should be incorporated to optimise both health and performance. This article will explore such considerations in greater depth focusing primarily upon: 

• Energy Availability
• Carbohydrate Intake
• Menstrual Cycle
• Iron
• Calcium

Note that the information in this article is based on the individual being healthy with no known medical conditions. For individuals with medical conditions, or those who are pregnant, please seek nutritional support from your doctor or dietitian.

Energy Availability

The foundation of nutrition for a female athlete should ensure that their total daily energy intake(the total amount of energy, calories, a person consumes through food and drinks in a single day) optimises their health and performance needs. Therefore, athletes should make the most of fueling opportunities presented to them throughout the day. 

Every time you eat is an opportunity to contribute towards your desired goals, be it performance, health or recovery. 

For example, if you eat six to eight times a day, you have 42 to 56 opportunities per week and up to 3000 feedings a year to meet your required energy availability (EA). 

EA is essential for optimal health and function. It is the amount of energy available to the body to perform all other functions after the energy used in exercise is subtracted. 

It has recentlybeen discussed as a more appropriate approach than energy balance (when an athlete’s total daily energy intake equals their daily total energy expenditure) to ensure that athletes are optimally fuelingboth their health and performance needs. 

Some male and female athletes consume insufficient energy to meet the needs for optimal body function once accounting for exercise. Such prolonged periods of low energy availability can lead to a syndrome known as Relative Energy Deficiency in Sport(RED-S).  

The below infographic highlights the physiological and psychological consequences of RED-S and the impact it can have on performance:

Parents, coaches, and support staff should not diagnose the cause of low energy availability. However, it is important for everyone to be able to identify signs and symptoms of RED-S and to signpost the athlete to appropriate support. For example, this could be a clinical dietitian, GP, clinical psychologist, or psychiatrist. 

Swim England has created an information document for athletes, parents, coaches, and support staff regarding low energy availability, which discusses this topic in much greater depth and highlights the appropriate support pathway for athletes. Further information and guidance regarding disordered eating and eating disorders is also provided within the document.

To meet the dailyenergy requirements to support optimal health and performance, athletes are encouraged to implement the below behaviors: 

• Do not skip meals
• Snack throughout the day
• Include a variety of foods and colours within dietary intake
• Pre-training meal/snack (such as a sandwich/wrap, a bagel, homemade flapjack or a smoothie).
• Bring snacks in to school, college, work, or in a training bag
• During training hydrate where necessary (dependent upon session intensity/duration)
• Post-training recovery nutrition(such as a chocolate milk, homemade flapjack, rice cakes with chopped bananas or a tortilla wrap) 
• Fluid bottles at training
• Post-training rehydration
• Enjoy your nutrition

Menstrual cycle

Daily energy intake plays a vital role in supporting the menstrual cycle. Female athletes who have irregular periods, or no periods at all, should consider whether this is due to their daily nutritional intake and low energy availability.  

For example, a symptom of RED-S amongst females is when periods have stopped. Athletes are encouraged to seek further support from their doctor if they feel they are having irregular periods or periods have stopped.  

There is a lack of evidence for the consumption of specific foods across different phases of the menstrual cycle. Athletes are therefore encouraged to adopt an individualised approach when it comes to their nutritional strategy, which considers their appetite and food cravings at certain stages within their cycle. Keeping a symptom diary can help to identify certain times within the cycle that athletes experience certain symptoms and any nutritional interventions can be reviewed. 

For further in-depth information regarding the menstrual cycle please view the following resources please click the link.

Macronutrient Intake

Carbohydrates

Carbohydrate intake is of great importance due to the daily energy demands placed upon athletes. As a result, carbohydrates form a significant part of an athlete’s daily energy intake requirements to optimise their energy availability. Carbohydrates are also an important fuel source for the brain and nervous system.

Carbohydratesare the primary energy source for aquatic athletes, especially those who perform at higher intensities, longer durationsand higher training volumes.

There may be variance in the carbohydrate requirements across the different aquatic sports (e.g. swimming compared to diving), whilst carbohydrate intake may vary amongst the individual from day to day based upon their daily needs (e.g. single training sessions days compared to double day training sessions). Athletes are encouraged to individualise their carbohydrate intake and fuel according to their training demands.

Fueling insufficiently with carbohydrates can result in lower energy stores in the body. This can influence health and performance, as highlighted earlier when discussing RED-S.For example, fueling carbohydrates can reduce the ability to work at higher intensities or when training over longer durations.

Furthermore, during high volume training blocks,failing to replenish carbohydrates sufficiently during recovery could see an athlete perform poorly at future training sessions, therefore impacting upon training adaptations. Chronically low carbohydrate intake could also increase susceptibility to injury or illness. 

Athletes who are still undergoing growth and development must ensure they are consuming enough energy each day to support their needs. Including carbohydrate options with meals and snacks throughout the day will help the developing aquatic athlete optimise their development, as well as their preparation, performance, and recovery. 

Carbohydrate meal examples 

• Porridge (or overnight oats) with fresh fruit, honey, nuts, and seeds.
• Scrambled eggs on toast with beans and glass of fresh juice.
• Yogurt with granola and fresh fruit.
• Sandwiches, wraps, bagels or pitta w/salad and protein option (e.g., chicken, tuna, halloumi).
• Stir fry with noodles and protein option (e.g., chicken, prawn, beef, tofu).
• Spaghetti Bolognese (or other pasta dishes).
• Chili con carne w/rice.
• Fajitas with protein option (e.g., chicken, beef, tofu).
• Homemade burgers w/homemade potato wedges.
• Jacket potato with beans and cheese.

Carbohydrate snack examples  

• Fresh fruit (e.g., apple, banana).
• Homemade flapjack or banana bread.
• Soreen loaf.
• Muesli or granola bar.
• Bagel or pitta.
• Flavoured milk.
• Flavoured yogurt w/granola or fresh fruit.
• Rice cakes or oatcakes w/peanut butter and chopped banana.
• Homemade smoothie (milk, flavoured yogurt, oats, frozen fruit, honey).

The inclusion of protein and healthy fat sources is also an important part of an athlete’s daily energy intake, with protein aiding muscle growth and repair, whilst fat intake will contribute to lower intensity activity and health.  

Further information regarding protein and fat intake will be found in future articles but here are some examples:

Protein 

Chicken, fish, eggs, red meat, milk yogurt, pulses, lentils, chickpeas, quorn, tofu, and cheese. 

Fats 

Avocado, olive oil, salmon, tuna, nuts, milk, eggs, cheese, olives, and nuts.

Iron

Iron is an essential micronutrient within dietary intake. Iron plays a significant role in transporting oxygen into the blood, increasing energy production and helping an individual’s immune health. 

Oxygen transport and energy production have great influence upon an individual’s aerobic performance. Aerobic performance is important to most aquatic athletes, highlighting the importance of iron inclusion in daily dietary intake.  

Female athletes are also of higher risk of iron deficiency due to menstruation and it is important that they are aware of their iron requirements and have suitable options included within their dietary intake. Research has shown that iron deficiency impacted 15-35% of female athletes and 5-11% of male athletes (Sim et al., 2019). 

Below are the possible signs of low iron status: 

Daily iron intake guidelines will vary based upon an individuals’ sex and age. Below are the UK guidelines: 

Group	Age	Iron (mg) per day
Adolescents (Girls)	11 to 18 years old	14.8mg
Adolescents (Boys)	11 to 18 years old	11.3mg
Adults (Female)	19 to 50 years old	14.8mg
Adults (Male)	19 to 50 years old	8.7mg
Adults (Male and Female)	50+ years old	8.7mg

Data source: NHS

There are various sources of iron, which can be categorised as animal based and plant based. Plant based sources can still contribute to daily iron intake, but animal-based sources are more absorbable. Female athletes who are following a plant-based diet should therefore be mindful of their iron options and how they can meet their requirements.  

Below are some examples of both animal based and plant-based sources and their approximate iron content: 

Iron and Vitamin C

Vitamin C plays a significant role in aiding iron absorption. Adding vitamin C rich foods and fluids within, or accompanying, iron containing meals is a nutritional approach that athletes could try to increase iron absorption.  

Such an approach could be useful for plant-based female athletes, who are at a higher risk of iron deficiency, as plant-based iron is less readily absorbed by the body compared to animal-based iron.  

Vitamin C can also provide further benefits including: an antioxidant to help with wound healing and maintaining healthy skin, blood vessels, bone, and cartilage.

Example Vitamin C Sources:

• Citrus fruits (e.g. oranges, fresh orange juice)
• Strawberries
• Blackcurrants
• Tomatoes
• Bell peppers
• Green leafy vegetables (e.g., cabbage, kale, spinach, and broccoli)
• Potatoes 

If supplementing with both a multivitamin and iron product supplement, ensure that you check the iron serving within the multivitamin and factor this in when determining the dose of the individual iron product. 

Iron Assessment

Where possible, athletes should utilise a food-first approach to improve iron status. However, this is dependent upon an individuals’ iron levels and supplementation may be necessary as part of the treatment plan.

Athletes should not supplement with iron without consulting with their doctor or dietitian first. Furthermore, it is important that the athlete undergoes an assessment to inform them of any supplement dose/strategy, as well as evaluating the impact that has on their iron levels. 

Calcium 

Calcium is important for the growth, maintenance and bone repair, as well as playing a role in nerve conduction, regulation of muscle contraction and blood clotting. Ensuring adequate calcium intake supports bone strength and density. If athletes are underfueling, and have low energy availability, this may risk low bone mineral density and stress fractures.  

Furthermore, female athletes should be aware that menstrual dysfunction and low calcium intake pose further risk to bone health. 

Daily calcium intake guidelines will vary based upon someone’s sex and age. Below are the UK guidelines: 

Group	Age	Calcium (mg) per day
Girls	11-18 years old	800mg
Boys	11-18 years old	1000mg
Adults	19 years old +	700mg

Data source: NHS  

Optimising daily energy intake in combination with a variety of calcium-rich foods can help the female athlete maintain strong bones and reduce the risk of stress fractures. Understanding the calcium content of various foods can help female athletes meet their nutritional requirements. Below are examples of calcium sources: 

Data source: NHS 

As highlighted above, dairy products are a rich source of calcium. However, there may be individuals who cannot, or choose not to, consume dairy. It is therefore important alternative calcium sources are chosen.

For those opting for plant-based milk alternatives, consider opting for options that are fortified with calcium. Calcium fortification of other products can also contribute to daily calcium intake. 

Calcium and Vitamin D

Vitamin D plays a crucial role in bone health due to its role in aiding calcium absorption. This will therefore support bone health. If you have low levels of vitamin D, then this may have a negative impact upon calcium absorption, which may compromise bone health. 

Before considering dietary intake, a major source of vitamin D can be through sensible exposure to sunlight, as vitamin D can be developed in the skin. When considering dietary intake, vitamin D sources may include oily fish (e.g. salmon, mackerel or sardines), red meat, egg yolks, and fortified foods.  

It can be difficult to optimise vitamin D status by diet alone. In the UK, during Autumn and Winter, exposure to sunlight is limited and therefore an athlete’s vitamin D levels may be lower.

Athletes can speak to a qualified nutritionist, dietician or doctorabout their vitamin D levels and they may opt to add a vitamin Dsupplement to their diet.  

Supplements

When it comes to an athletes’ nutrition strategy,an emphasis should be placed upon a food-first approach.

This simply means that an athlete should look to optimise their dietary intake first before considering the use of evidence-based supplements.

But what is a supplement?

A food, food component, nutrient or non-food compound that is purposefully ingested in addition to the habitually consumed diet with the aim of achieving a specific health and/or performance benefit.

Maughan et al (2018).

This is not to say that it should always be a food-only approach. There may be examples where supplementation may need to be considered: 

• Some nutrients are difficult to obtain in sufficient quantities in the diet or may require excessive energy intake and/or consumption of other nutrients. 
• Some nutrients are abundant only in foods athletes do not eat or like. 
• The nutrient content of some foods with established ergogenic benefit is highly variable. 
• Concentrated doses of some nutrients are required to correct deficiencies and/or promote immune tolerance. 
• Some foods may be difficult to consume immediately before, during or immediately after exercise. 
• Batch-tested supplements could help where there are concerns about food hygiene or contamination. 

This is why it is important to have suitably qualified nutrition professionals, such as a performance nutritionist/dietitian consulting with athletes who are considering supplementation. 

Swim England has worked closely with Aquatics GB to ensure a consistent message regarding the use of nutritional supplements and medications. 

Swim England does not promote the use of nutritional supplements by athletes under the age of 18 unless advised by a doctor, SENr accredited nutritionist or dietitian. 

Swim England has published a statement regarding supplements which can be viewed here. 

There are no 100 per cent guarantees that a supplement is free from prohibited substances and the individual must be fully aware of the risks and consequences when considering taking a supplement – and remember ‘strict liability’ in relation to anti-doping.  

 You can find a link to the Swim England anti-doping page here.

Athletes can minimise the risk by considering products that have been batch tested and accredited by Informed Sport. Informed Sport is a global testing and certification programme for sports and nutritional supplements. Supplement products are tested for contamination against a broad range of banned substances in sport. 

You can find out how to check a supplement on Informed Sport via this link.

Athletes should keep a record of their supplement history to detail all supplements taken and the date they were checked on Informed Sport. 

When it comes to supplementation it is important to: 

• Assess the need – First consideration should be to consult with a suitably qualified nutrition professional, such as a performance nutritionist or dietitian, to ensure that there is rationale to supplement and that only evidence-based supplements are considered. 
• Assess the risk – Only consider products that are accredited with Informed Sport. Check that the supplement product batch number ID is listed on the Informed Sport website. 
• Assess the consequences – Remember that if the supplement is found to violate anti-doping rules, then athletes may be banned from training and competing. 

Summary

Nutrition plays a significant role for the female athlete to achieve optimal performance and maintain long-term health.  

By focusing on key areas such as energy availability, iron intake, calcium consumption and vitamin D, female athletes can support their unique needs and demands. If further support is needed, female athletes are encouraged to seek guidance from their doctor or a suitably qualified nutritionist or dietitian.