A Closer Look at The Components Of a Balanced Diet Vitamins, Minerals, Water and Dietary Fibre

Vitamins

Vitamins are chemical compounds which help to convert food fuels into energy, support the immune system and help the brain to function properly. Although vitamins themselves contain no usable energy, they form components of enzymes which help to release energy from our main energy providers – carbohydrates and fats.

The body is not able to produce most of the vitamins required to maintain health so they must be consumed in our diet. A variety of foods are good sources of vitamins, including fresh fruit and vegetables, cereals, eggs, fish and meat. Each vitamin has a particular function and individual requirements depend very much upon a person’s age, sex, state of health and exercise levels.

Nutrition experts suggest that vitamin supplementation should not be necessary in a healthy balanced diet. Despite this, some athletes insist on taking mega doses of up to 100 times the recommended daily allowance (RDA) in the hope of bringing about improved performance. This practice can cause health problems and cause performance to suffer.

Recommended Daily Allowances (RDAs): set by the EU, RDAs are estimates of the necessary nutrient requirements to meet the needs of the majority of the population.
  1. You are coaching a young athlete. They have told you that they would like to take a number of vitamin supplements. What steps would you go through with them and what advice would you give in order for them to make an informed decision?

Minerals

Minerals are inorganic compounds found in the body that are vital for effective cell functioning. We gain minerals almost exclusively from the food and water we consume. Although minerals are only needed in relatively small amounts (hence why they are a micronutrient) they have a wide range of roles which can significantly affect performance. A variety of foods are good sources of minerals, including fresh fruit and vegetables, cereals, eggs, meat and fish. Below is a list of the functions of minerals in exercise:

  • Calcium contributes to the formation of bones and teeth as well as playing a vital role in muscle contraction and nerve transmission
  • Phosphorus is an essential component of adenosine triphosphate and creatine phosphate both high energy components in the body
  • Iron is a major component of haemoglobin and myoglobin, our oxygen transporters in the body
  • Sodium, potassium and chlorine form electrolytes which help to maintain the correct rate of exchange of nutrients and waste products into and out of the muscle cells
Adenosine triphosphate (ATP): a high energy compound found in all muscle cells which is broken down to release energy for all purposes.
Creatine phosphate: a compound found in the muscle cells which is broken down by enzymes to quickly replenish ATP stores.
Electrolytes: substances that help to maintain the optimum rate of exchange of nutrients and waste products into and out of the muscle cells.
  1. What type and for what reason would a mineral deficiency hinder an endurance athlete?

Water

Up to 60% of a person’s body weight is comprised of water. Drinking water is therefore an essential daily activity since nearly all processes in the body take place in a watery medium. The following are functions of water in exercise:

  • Water forms the foundation of the body’s transport network so is responsible for transporting oxygen, nutrients and hormones to the body’s cells and the removing of harmful waste products such as carbon dioxide.
  • Water helps to regulate and maintain core body temperature through sweating. Losing the equivalent of 2% of your body weight as sweat can impair performance by up to 10-20%. If you do not replace the lost water the following can occur:
  • Core temperature increases which inhibits performance
  • Blood becomes thicker which slows the supply to the muscles
  • To compensate the heart rate increases stressing the body
  • Lost electrolytes can cause fatigue and cramp
  1. What factors are going to affect how much water is lost through sweat when exercising?
  2. What advice would you give to the England Football team regarding hydration during the World Cup in Qatar in 2022 where daytime temperatures exceed50°C (122°F)?

Dietary Fibre

An essential ingredient in every athlete’s diet,fibre helps the digestive system to function properly by absorbing water and helping the passage of food through the gut. In doing so it prevents constipation and promotes a healthy bowel.

Good sources of fibre are found in whole wheat bread, brown rice and vegetables. Some soluble fibres found in pulses, fruit and vegetables can also reduce cholesterol levels and control blood glucose levels by slowing down the absorption of glucose.

According to the Department of Health, an athlete’s diet should consist of between 18g and 24g of fibre per day. The following are functions of fibre in exercise:

  • Insoluble fibre absorbs water in the intestine which helps to excrete waste from the body.
  • Soluble fibres contribute to lowering cholesterol in the blood by minimising the absorption of fat and cholesterol from foodstuffs.
  • Soluble fibre can also maintain blood glucose levels by reducing the rate of glucose absorption.
  1. How might soluble fibre help an athlete to maintain energy levels during endurance events? Link your answer to GI foods.