NOTE: The following information is for educational purposes only and does not reflect the opinion of Glanbia Performance Nutrition, nor is it intended for product marketing purposes.
By Ruth Drennan- Munster Rugby Nutrition Intern
Nutrition requirements for female athletes are special and require consideration. Requirements differ from male athletes due to hormonal changes around menstruation. A typical menstrual cycle lasts 21-36 days so has the potential to impact nutrition and training on a regular basis. It can often be a difficult conversation to have with female athletes but as their PT it may be beneficial as it can impact their training and nutrition and puts you in a better position to help them or adjust training/nutrition accordingly.
What do you need to consider in the 1-2 weeks coming up to a client’s period?
- Weight fluctuation is completely normal with some females experiencing changes of up to 2.5 kg due to hormonal changes and fluid retention.
- Core temperature is elevated in the days leading up to menstruation so they may need extra fluid to ensure they are hydrated enough compared to the rest of the month.
What is PMS?
Premenstrual Syndrome (PMS) is a series of symptoms commonly experienced by females 1-2 weeks before menstruation (luteal phase). Symptoms vary, but include mood swings, irritability, headaches, bloating, breast tenderness, and increased appetite, carbohydrate and alcohol cravings.
What do clients need to consider during their period?
In truth, nutritional science is not at a point where we can confidently advise clients on specific nutritional strategies relating to the exact stage of their menstrual cycle. However, there are some considerations that may help alleviate some of the effects of the menstrual cycle;
- Sufficient calcium and vitamin D is associated with a lower incidence of PMS. Dairy products such as milk and yogurt are good sources of both calcium and vitamin D and have been found to reduce the incidence of PMS1.
- Magnesium may have a role with lower intakes commonly found among those experiencing PMS2. Magnesium rich foods include; green vegetables and wholegrain breakfast cereals.
- Higher intake of B vitamins; thiamine and riboflavin may reduce the incidence of PMS by 35%3. These B vitamins are found in fortified breakfast cereals, bread, eggs, milk, yoghurt, nuts, pulses
Iron – Why does it matter?
Iron is a key nutrient to be mindful of in females due to the blood loss during a period which may contribute to lower than usual iron levels. Iron has a role in energy production and oxygen transport in the body. It delivers oxygen to the cells to allow energy production. Iron also has a role in neural, immune and cognitive function.
What effect can low Iron levels have on performance?
- If iron levels are very low, the athlete may have “Iron Deficiency Anaemia”. This can result in impaired performance, fatigue, reduced endurance, and aerobic capacity.
What food has iron?
There are two types of iron in food; Haem iron and Non-Haem iron. Haem iron is more easily absorbed in the body compared to non-haem iron. As illustrated below, haem is primarily found in meat and fish, whilst non-haem is largely derived from plant sources, meaning we absorb more iron from meat and fish than we do from plant sources. This is particularly important if any of your female clients are vegetarians as they have an increased risk of an iron deficiency.
Haem Iron (Animal foods)
- Meat: Beef, Pork, Poultry, Lamb, Duck, Venison, Liver, Kidney
- Seafood: Mackerel, Trout, Bass, Tuna, Sardines , Oysters, Shrimp, Clams, Scallops, Crab
Non-Haem Iron (Plant foods)
- Tofu: Extra firm has more iron than soft, medium, or firm tofu
- Legumes: lentils, chickpeas, black-eyed peas, split peas, black beans, baked beans, pinto beans, kidney beans, soybeans, hummus
- Nuts / Seeds & Nut butters: Almonds, Cashews, Hazelnuts, Pistachios, Soy nuts, pumpkin, sunflower, sesame
- Grain products: Fortified cereals, pasta, oats
- Soy products: Fortified soy beverage, soy yoghurt, tempeh
- Vegetables: cooked spinach, asparagus, beets
What can you do to enhance iron absorption?
Iron Absorption Boosters
- Pair iron sources with a source of vitamin C.
e.g eat pasta with tomato sauce
e.g add peppers to chickpea / lentil dishes
e.g have 1 glass of orange juice with breakfast cereal / porridge / egg dish
- Animal protein (meat, fish, poultry) helps increase absorption of non-haem iron.
e.g add lentils to bolognaise
e.g Have wholegrain pasta with chicken
Iron Absorption Blockers
Tea and coffee contain “tannins” which reduce the absorption of iron. Try and avoid having tea or coffee within 1 hour around meal time.
What are the signs and symptoms of Iron Deficiency Anaemia?
- Heart Palpitations
- Brittle nails
- Thinning Hair
- Itchy skin
- Mouth sores / ulcers
How much Iron do females need?
Females need 14-15 mg per day4 but Iron requirements can be higher during menstruation if the client experiences heavy blood loss (up to 18mg)5.
If a female thinks she has low iron levels, should they take a supplement?
No. There is no justification for taking iron supplement in the absence of a diagnosed iron deficiency. Excessive iron supplementation can result in GI disorders – constipation, cramps8.
Causes of Iron deficiency in athletes
- Physiological: Athletic training & strenuous exercise = increased iron turnover in tissue and increase in iron loss from exercise associated mechanisms = increased iron requirements
- Growth spurts (adolescents and children)
- Menstruation is not normally a major causal factor of iron deficiency in athletes except those with heavy or frequent blood loss
- Low energy diets which don’t provide enough iron rich foods
Although we may not be able to give nutritional recommendations based on a client’s stage of their menstrual cycle, you can still take certain steps to help manage symptoms and avoid further deficiencies. Ensuring clients have sufficient micronutrient intakes with a particular focus on calcium, vitamin D, magnesium and B vitamins may reduce the PMS symptoms. This can be done by highlighting the importance of micronutrients and promoting a varied diet high in fruit and vegetables. In Ireland and the UK, it can be particularly hard to obtain sufficient vitamin D during the winter months so this may need supplementation!
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- Bertone-Johnson ER., et al 2005. Calcium and vitamin D intake and risk of incident premenstrual syndrome. Arch Intern Med.
- Quaranta S., et al 2007. Pilot study of the efficacy and safety of a modified-release magnesium 250 mg tablet (Sincromag) for the treatment of premenstrual syndrome. Cin Drug Investig.
- Chocano-Bedoya PO., et al 2011. Dietary B vitamin intake and incident premenstrual syndrome. Am J Clin Nutr.
- FSAI. Recommended Dietary Allowances for Ireland. Ireland: Food Safety Authority Ireland; 1999.
- Castell LM, et al., 2019. Exercise-induced illness and inflammation: Can immunonutrition and iron help? Inter journal of sport nutrition and exercise metabolism.
- Goodman C, et al., 2011. A to Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance--Part 21. Br J Sports Med.