Healthy eating habits/Dairy and Post Exercise Nutrition

Good post exercise nutrition is vital for optimal recovery. Dairy foods offer a variety nutrients that aid recovery and thus, assist in enhancing performance.

Dairy
Dairy includes milk and products containing or made from milk. The dairy food group can also include soy and lactose-free alternatives that have similar nutrient profiles to dairy products. Examples include:
 * Milk
 * Yoghurt
 * Cheese
 * Custard
 * Dairy desserts

According to the Australian Dietary Guidelines, one serve of dairy is equivalent to a 250mL glass of milk, 200g tub of yoghurt, or two slices of cheese, and low or reduced fat varieties are best.

Whilst dairy products can provide us with many different vitamins and minerals such as calcium, vitamin A, riboflavin, vitamin B12 and vitamin D, in sports nutrition we focus on the carbohydrates, protein and electrolytes in dairy, and how they can help with sporting performance and recovery.

What are Carbohydrates?
The main role of carbohydrates is to provide us energy. Carbohydrates can be divided into two groups; complex and simple. Complex carbohydrates, or dietary starch, come from foods such as whole grains (pasta, oats and whole-grain bread) and legumes, and simple carbohydrates or sugars, are found in fruit, honey, lollies and soft drink. Dairy products contain simple carbohydrates for a quick source of energy.

What is protein?
Protein is required for muscle repair and building. Some major sources of protein include, meat, poultry, fish, eggs, milk, beans, nuts and legumes.

What are electrolytes?
The electrolytes, sodium (salt) and potassium, are needed to prevent and recover from dehydration.

Post Exercise Nutrition
Good nutrition after exercise is essential for optimal recovery, so that we can exercise on a regular basis and performance can improve.

There are three main nutrition goals of recovery:
 * Rehydrate
 * Refuel
 * Repair

Rehydrate
Rehydration should start immediately after exercise to replace fluids and electrolytes lost in sweat. The human body is composed of up to 60-70% water. Fluid is lost from the body via urine, faeces, sweat, evaporation, and breathing. The main cause of dehydration, however, is loss of fluid through sweat. The amount of sweat varies greatly between individuals, but also within individuals as it depends on activity level and surrounding climate.

Why don’t we want to get dehydrated?
Fluid losses of around 2% of your body weight are enough to cause a decrease in muscle function and performance (strength, endurance and stamina) and dizziness, and as dehydration worsens, it can cause loss of coordination, nausea, vomiting, diarrhoea, overheating and collapse.

So, it is essential to restore the fluid lost during exercise through sweat to prevent dehydration.

The electrolytes, sodium and potassium, aid fluid restoration and act to replace any salts lost through sweat. Sodium also helps with fluid absorption and potassium can help prevent muscle weakness and mental confusion that occur when levels are low due to sweating. Milk and liquid or semi-solid dairy products (yoghurt, smoothies, custard) provide both fluid and electrolytes, to help with rehydration after exercise.

Refuel
After exercise, it is important to refuel with carbohydrates so that muscle and liver glycogen (carbohydrate) stores can be replenished. Carbohydrates are our main fuel source, and when exercising and as our heart rate increases, our body uses carbohydrates more quickly than usual. Just like petrol in a car, we need to refuel when the carbohydrate stores in the body get low. If we don’t refuel after exercise, it can affect our ability to train and compete on subsequent days and cause muscle fatigue.

Dairy products are a great source of the simple carbohydrate, lactose. They are also a great alternative to other carbohydrate fluids such as sports drinks, which can cause tooth decay due to their high acidity.

Repair
Both prolonged and high intensity exercise cause a breakdown of protein in muscle. It is important to have protein in the first hour after exercise to replace the protein lost during exercise, and repair muscle tissue and encourage growth to recover and improve future performances.

Dairy Snack and Meal Ideas for Recovery
An ideal snack or meal for recovery should include fluid, electrolytes, protein and carbohydrates, as they all play major roles in recovery. Furthermore, carbohydrates increase the uptake of protein, so these should be consumed together. The snack or meal should be consumed within an hour after exercise for optimal recovery.

As dairy products contain fluid, electrolytes, protein and carbohydrates, they can be ideal for recovery. Dairy alternatives such as soy milk and lactose-free products are also beneficial, if you don’t tolerate lactose or dislike milk.

Table 1.0 - Post-exercise snack ideas that include dairy.

Table 2.0 - More substantial post-exercise snacks

Further Reading and Advice
Sports Dietitians Australia Fact Sheets

Dietitians Association of Australia Fact Sheets

See an Accredited Practicing Dietitian or Accredited Sports Dietitian

For more tips on Healthy Eating, see the contents page; Healthy eating habits

For other chapters of the book on nutrition and exercise see:
 * Healthy eating habits/Nutrition for Cycling: Eating well to optimise training
 * Healthy eating habits/Nutrition & Quick Snack Ideas for Sport Performance
 * Healthy eating habits/Sports drinks: are they really doing us good?
 * Healthy eating habits/Hydration for Adolescent Athletes
 * Healthy eating habits/Preparation for Game Day Eating
 * Healthy eating habits/Post-Workout Nutrition
 * Healthy eating habits/Dairy for Health & Performance in Sub-elite Female Cyclists
 * Healthy eating habits/Effective Eating for Dancers: Eating for Energy, Concentration and Focus