Macronutrients are the nutrients that people need at a ‘macro’ level to perform and function optimally. ‘Macro’ refers to a large scale, whereas ‘micro’ refers to a smaller scale. Therefore, these are the nutrients that people need to consume in large amounts to supply them with the energy to perform and function in the best way possible for the activity level that they are involved in.

There are three main macronutrients - Carbohydrates, Fats and Proteins.

Carbohydrates

Carbohydrates are the body's primary source of energy. They are broken down into glucose (sugar) in the body which fuels various functions. They provide readily available energy for muscles and organs, helping regulate blood sugar levels. These nutrients can contribute to a feeling of fullness and support brain function.

There are two main types of carbohydrates: simple and complex.

 Simple Carbohydrates: Provide quick energy but are often low in nutrients. Found in sugary drinks, lollies, processed foods and some fruits.

Complex Carbohydrates: Provide sustained energy and are higher in fibre and other nutrients. Found in whole grains, vegetables, legumes and some fruits.

Complex carbohydrates are especially important as they provide sustained energy release. Individuals can aim to include a variety of whole grains, fruits and vegetables in the diet to support their workouts. Carbohydrates are the primary source of fuel for predominantly aerobic activity, especially at higher intensities. Complex carbohydrates should be consumed in advance of the activity to ensure adequate glycogen stores. Simple carbohydrates can be used to ‘top up’ energy. Predominantly anaerobic workouts also rely on carbohydrates stored as glycogen in the muscles for fuel. Source: https://www.nlm.nih.gov/

 Fats are essential nutrients that provide energy, insulation, and support for cell growth and hormone production. Fats provide long-lasting energy, help absorb certain vitamins. They also contribute to a feeling of fullness, cushion organs and insulate the body.

There are three main types of fats: saturated, unsaturated and trans fats.

Saturated Fats: Should be limited in the diet as they can raise LDL (‘bad’) cholesterol. Found in red meat, processed meats, full-fat dairy products and some plant sources like coconut oil.

Unsaturated Fats: Include monounsaturated and polyunsaturated fats, which can help lower LDL cholesterol and raise HDL (‘good’) cholesterol. Found in fatty fish, avocados, nuts, seeds and olive oil.

Trans Fats: Should be avoided as they contribute to heart disease risk. Found in some commercially baked goods, fried foods and processed snacks.

Fats are an important source of energy for active individuals, especially during longer endurance activities. Choose healthy sources of unsaturated fats to support workouts and overall health. Predominantly aerobic activities utilise fats as a secondary source of fuel, once carbohydrate stores are depleted. Predominantly anaerobic activities can not use fats, as oxygen is required to produce energy.

Sources:

https://www.mayoclinic.org/

Academy of Nutrition and Dietetics- https://www.eatright.org/

 Protein is essential for building, repairing and maintaining tissues all throughout the body. They build and repair muscles, bones, skin and hair. Protein make enzymes that help with various bodily functions, help transport nutrients throughout the body and support the immune system.

There are two main types of proteins: complete and incomplete.

Complete Proteins: Contain all nine essential amino acids that the body cannot produce on its own. Found in animal sources like meat, poultry, fish, eggs and dairy products.

Incomplete Proteins: Lack one or more essential amino acids. Can be combined with other plant-based protein sources to create a complete protein profile. Found in plant sources like beans, lentils, nuts, seeds and whole grains.

Protein is crucial for building and repairing muscle tissue, which is essential for recovery and adaptation after exercise. Active individuals have a higher protein requirement compared to sedentary people. Protein provides the building blocks for muscle repair following exercise, which helps you recover faster and build strength. Adequate protein intake can help improve exercise performance and endurance. Protein may help reduce muscle soreness after exercise. Protein may also be used to a small degree for energy in predominantly aerobic activity, if carbohydrate and fat stores are depleted.

Protein is a chain of amino acids and provides the building blocks for all the cells in the body. It is particularly important for muscular growth and repair, and can be used as a fuel source.

It is recommended that people eat 0.8g of protein per kg of body weight. This is enough to maintain current body mass and is sufficient in providing for any possible energy needs. When resistance training is undertaken for muscular hypertrophy protein consumption should increase to 1.2 - 2.0g per kg of body weight per day in order to grow muscle size. It should be noted though that this upper limit for an athlete weighing 100kg is still only 180g because meat, dairy and eggs are high in amino acids.

Supplementation is not required for most Western athletes. If the athlete is a vegetarian or vegan, amino acids are usually consumed through beans, nuts and legumes and would need to be monitored in order to ensure adequate amounts are being eaten. If not, then supplementation may be beneficial.

Supplementation may also be beneficial because it can improve the timing of protein consumption. Protein consumed within 1hr of resistance training may help recovery and increase hypertrophy.  Excessive consumption can have a detrimental effect on health, particularly kidney function.

Athletes in aerobic activity require protein to help reduce muscle breakdown from prolonged activity. For anaerobic activities because there is more muscle damage, protein is required to support muscle repair, growth and hypertrophy. Timing, size, sources and age can vary from one athlete to the next.

Sources:

https://www.nlm.nih.gov/

https://www.acsm.org/

‘Micronutrients are vitamins and minerals needed by the body in very small amounts’ (WHO, 2024). They are just as important to ensure the proper functioning of the body. There are about 30 micronutrients that the body cannot adequately produce, these are known as ‘essential micronutrients’. Active people may require more of particular nutrients than inactive people.

https://www.who.int/health-topics/micronutrients#tab=tab_1

https://www.health.harvard.edu/staying-healthy/micronutrients-have-major-impact-on-health

Vitamins and minerals are organic compounds found in high concentrations in fruit and vegetables. Though they are all needed for proper bodily function, there are a few that are important for performance.

The body requires several important vitamins for optimal functioning, including B vitamins, vitamin D, vitamin C, vitamin E and beta-carotene.

B vitamins play a crucial role in energy production and the building and repair of muscle tissue. They are also essential for the production of red blood cells, supporting overall health and athletic performance.

Vitamin D is necessary for proper calcium absorption, which promotes strong bone health. Additionally, it helps regulate the homeostasis of the nervous system and skeletal muscles, ensuring their proper function and balance.

Antioxidants such as Vitamin C, vitamin E and beta-carotene protect cell membranes from oxidative damage. During exercise, oxygen consumption increases, leading to a higher risk of oxidative damage. As a result, the body requires a greater intake of these antioxidants to combat the harmful effects of increased oxidative stress.

Several minerals are vital for optimal athletic performance, including iron, zinc, magnesium, potassium, sodium, chloride and calcium.

Iron is critical as it provides haemoglobin and myoglobin with their structure, enabling the transportation of oxygen throughout the body and within muscles. Insufficient iron levels can reduce the availability of oxygen, limiting the body’s ability to sustain high-intensity activities that rely on the aerobic energy system. This deficiency also impacts the the recovery of anaerobic energy systems, delaying post-performance recovery.

Calcium is essential for bone repair, growth and development. It is also vital for muscle contraction and nerve conduction, allowing efficient transmission of messages in the body. Calcium and iron are particularly crucial for female athletes, as they are at higher risk of deficiencies in these minerals.

Zinc supports the growth and repair of muscle tissue, making it a key mineral for athletes engaged in strength and endurance activities.

Magnesium plays an important role in muscular contraction and glycolysis, the process of breaking down glucose for energy. A deficiency in magnesium can increase oxygen requirements during submaximal efforts, reducing efficiency.

Sodium, chloride and potassium are electrolytes that are crucial for neural transmission. Sodium, in particular, is vital as it is lost through sweat during exercise. Replenishing sodium and potassium is often achieved through sports drinks, which help maintain electrolyte balance during prolonged physical activity.

Supplementation of these micronutrients is only necessary when adequate amounts can not be obtained through a regular, balanced diet. A nutrient-rich diet typically provides the necessary levels of the essential minerals for most athletes.