What is Nutrition?
Nutrition or the food we eat provides nutrients that have a range of physiological and biomechanical functions such as respiration, repairing damaged cells or enabling movement. Without food then we cannot function and eating a good diet reduces disease risk and maintains overall health and well-being. For runners or any athlete the basic importance of nutrition is that it provides energy in order to complete an activity and the food we eat impacts our strength, performance, training and even recovery. An optimal diet is one that supplies all 6 key nutrients (carbohydrates, protein, fat, vitamins, minerals and water) in adequate amounts in order to provide energy, promote the growth, repair and development of cells, and to regulate metabolism. But what are each of these basic nutrients and what are they used for?
To put it simply, carbohydrates are the sugars, starches and fibre found in foods such as fruits and vegetables, grains (e.g. rice, bread or pasta) and milk products. Each carbohydrate molecule is made up of carbon, hydrogen and oxygen, for example the chemical formula for glucose is C6H12O6.
We can get simple carbohydrates that provide quick absorbing energy as these sugars are made from only one or two sugars and we can get more complex carbohydrates that release energy more slowly because it takes times to break the chemical bonds between the long chain of sugars. Examples of simple carbohydrates include sports drinks, energy gels or sweets whilst complex sources include whole-grains such as brown rice or starchy vegetables such as sweet potatoes.
The main function of carbohydrates is to provide energy and they are the primary fuel source when exercising at high intensity as they are the most efficient energy source. Now carbohydrates (for general health) are often associated with poor health connotations but we need them for performance.
You’ve probably heard lots about protein; from protein shakes and bars, the protein content of chicken vs. tuna and the ever growing list of products that have added protein such as protein Weetabix – Yes really! Despite the food industry seemingly glorifying the importance of protein, it is actually a vital component of a healthy diet because they help repair damaged cells and build new ones and allows normal body functioning and metabolic reactions to take place.
Proteins themselves are large molecules made from amino acids. Different proteins have different amino acid chains and there are 9 essential amino acids that we must get from food and 11 that the body can synthesize itself.
Athletes and runners may require protein in greater amounts than the general population. This is because during intense work protein can act as a fuel source (just like carbohydrates and fat) and after intense exercise the rate of protein synthesis can increase by 10-80%.
Fats come in a variety of different forms including trans, saturated, unsaturated, monounsaturated and polyunsaturated fats. Like carbohydrates each fat molecule is made up of carbon, hydrogen and oxygen (in different quantities to carbohydrates) and there are three different types of dietary fat (triglycerides, cholesterol, and phospholipids).
Similarly to protein, there are some essential fatty acids that our bodies cannot make on their own. These two essential fats are alpha-linoleic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid).
Fats are often demonised but are vital for a range of essential body functions such as providing an energy reserve, protecting vital organs and helping absorb essential fat-soluble vitamins such as A, D, E and K. Ensuring adequate consumption of these vital fats is important to manage inflammation, enhance muscle recovery as well as protecting cardiovascular function.
Vitamins and Minerals
In comparison to the three macronutrients (carbohydrate, protein and fats) we only need to consume a very small amount of vitamins and minerals, also known as micronutrients. Although neither vitamins nor minerals provide any useful energy they play vital roles in a number of metabolic reactions.
Whilst vitamins and minerals are often considered the same, biologically they are a little different. Vitamins are organic compounds made by plants or animals whilst minerals are inorganic elements that occur naturally in nature and come via rocks, soil or water.
The body requires vitamins and minerals for a number of key functions such as maintaining bone health, regulating aerobic metabolism, protecting against oxidative stress or transmitting nerve impulses. Athletes and runners may require a greater level of vitamins and nutrients (research has shown that these to include iron, calcium, zinc, magnesium, B-vitamins and anti-oxidants) because of potentially higher rates of energy metabolism and overall energy expenditure.
However, taking too much of a micronutrient may increase the risk of creating a toxic environment within the body which could cause a number of harmful side effects.
Whilst we could potentially survive for up to a month without food, in a desert environment it may only be possible to survive for up to 2 days. So water (chemical formula of H2O) is essential for human life, but why do we need it? Well it helps to regulate body temperature, carries nutrients to organs and cells and helps remove waste products from the body to name a few.
It is widely accepted that adults should consume between 2-2.5 litres of water daily through both food and drinks however athletes may need more due to a variety of factors. When we run, most of the energy is converted into heat and dissipates from the body in the form of sweat. Therefore running in hot conditions increases the amount of fluid lost from the body.
If we do not stay hydrated then the body cannot perform at the highest level and you may feel tired, dizzy, experience muscle cramps and potentially other serious health implications. However being over hydrated can lead to even more potentially serious health implications therefore it is advised to drink to thirst.
“Athletes do not diet and exercise. We fuel and Train”