Bicycle Network: Women's Cycling
Nutrition for active women
Eating for optimal health, energy levels and performance.
Women have specific nutritional needs over their lifespan. But if you are an active woman there are additional dietary considerations to ensure your optimal health, energy levels and performance. Sports dietician Lisa Sutherland dishes up some good advice.
Active women face an increased risk of low iron levels, as regular exercise may increase iron requirements.
Iron is part of the haemoglobin in red blood cells. Haemoglobin picks up oxygen from the lungs and carries it to the muscles and brain. Without enough iron we are unable to transport oxygen and convert food to energy. This can lead to symptoms such as fatigue and lowered immune function.
Factors that contribute to low iron stores include:
- inadequate dietary iron intake
- blood loss through injury or heavy periods
- heavy exercise
Iron from animal sources (haem iron) is more easily absorbed than iron from plant sources (non-haem iron). Women often consume inadequate iron, particularly if they are vegetarian or have a reduced kilojoule intake. Eating food that is rich in vitamin C with non-haem sources can improve iron absorption.
The recommended daily intake for iron for pre-menopausal adult females is 12-16mg, but more active women may need more than 20mg per day. Pregnancy and breastfeeding also increase the amount of iron the body requires.
Sources of iron include:
- liver and kidney
- red meat
- legumes such as dried beans, lentils and chickpeas
- nuts and seeds
- fortified breakfast cereal
Sources of vitamin C include:
- kiwi fruit
- red capsicum
Symptoms of iron deficiency include fatigue, impaired immune function and always feeling cold. A visit to your doctor may be required if you are experiencing excessive fatigue, and a blood test will determine if your iron stores are adequate. If your iron levels are low it is likely you will be advised to increase your dietary intake of iron, and possibly also take an iron supplement. It is important, however, not to self-diagnose and decide yourself that you need an iron supplement - in large doses iron may impair the absorption of other minerals and may also cause gastrointestinal discomfort.
Calcium is essential for bone development and muscle function. Women need extra calcium, as they have a greater risk of developing osteoporosis (weakening of the bones), which generally occurs after menopause.
Women reach peak bone mass in their twenties, so calcium intake in the teenage years is critical. However, as you get older, you can also protect your bones through a calcium-rich diet and regular weight-bearing exercise. Staying fit can improve bone strength, and active women are less at risk of developing osteoporosis than women who lead a sedentary lifestyle.
The recommended daily intake of calcium is 800-1000 mg per day. If you are pregnant or breastfeeding, you will need to increase your daily dose.
Dairy foods are the best source of calcium. Low-fat dairy foods have a low glycaemic index, providing a sustained release of energy for busy workdays, or as a pre-ride meal or snack.
Sources of calcium include:
- low-fat milk, yoghurt and cheese
- fortified soy products
- canned salmon (including bones!)
- green leafy vegetables
- nuts and seeds
Some people have an allergy or intolerance to dairy, or simply choose to avoid dairy foods for other reasons. Dairy foods are the richest food source of calcium and it may be difficult to meet calcium requirements without dairy in the diet. Calcium supplements can be useful in situations where dietary intake is inadequate, and are often prescribed for women with osteoporosis or decreased bone density as a greater intake above RDI may be beneficial.
Folate is a B vitamin that is needed for the development of new body cells. Folate intake is particularly important for women planning a pregnancy, with intake recommended at 400 micrograms per day - double that required for the general population.
Sources of folate include:
- dark-green leafy vegetables
- some fruits
- nuts (e.g. almonds)
- legumes (e.g. Lentils, kidney beans)
- fortified cereals, breads and pastas
We all have busy lives, juggling family, social activities, work and exercise. Whether you ride a bike for leisure or get into serious racing, you need to eat for energy, which takes forward planning and organisation.
Small meals and snacks spaced throughout the day are the way to go, with extra carbohydrates before, during and after longer rides. If you don't eat enough, you will become tired and run-down.
Sources of carbohydrates include:
- pasta and noodles
Achieving and maintaining a healthy weight is a matter of creating a balance between kilojoules eaten and kilojoules burnt. The key is to keep it simple:
small portion sizes
eat three small meals and two or three small snacks
choose foods in their natural state, the less processing the better
drink plenty of water
Fad diets do not work for long-term weight loss and good health. Don't fall into the diet trap - you need to be able to burn fat during exercise, and that is why restrictive diets do not work.
Lisa Sutherland is a sports dietitian and fitness consultant who works for the Hawthorn Football Club and the Victorian Institute of Sport. Visit her website at www.lisasutherland.com.
Tell me more about women's fitness issues, including premenstrual syndrome, menopause, osteoporosis and contraception.