Nutrition foundations
An overview of macros, calories, and energy expenditure related to rugby
- By Laura Kealy - Performance Nutritionist, Bridge Nutrition
The idea of nutrition, and what it entails, can be many different things to many different people. For some it is dieting, for some it is eating to perform, and for some it is too complicated to try and understand.
The simple definition of nutrition is:
“The process of taking in food and using it for growth, metabolism, and repair.”
We need food and water for our bodies to grow, provide energy, repair, and keep us strong. This applies not only to training and matches, but also to daily life. Specific foods, and the quantity at which we consume them, will have a direct influence on the rate at which we fuel and recover from training and matches. Some foods will be very effective in helping us do this and some foods not so much!
We need energy to go about our busy daily lives, and this energy comes from food in the form of calories. The number of calories in a food is simply the amount of potential energy it has. This energy is used for bodily functions, from our hearts beating to our brains thinking. It is also used in movement, from the morning time clean up after breakfast, to completing a tough session in the gym.
Ideally, we aim to be in a calorie balance, this means that we match our calorie intake with our calorie output, and in doing so we do not over or undereat. To do this we must listen to our bodies. If you feel exhausted after a few days of heavy training despite getting enough sleep then you may need to address your overall energy intake. Conversely, if you find that some of your clothes are feeling a bit tight after a few weeks of reduced training but unchanged eating habits then you may be eating in excess of your requirements. Calories are often over-complicated, or even dismissed by some, but to put it simply – calories give us energy.
Food contains nutrients which are substances that provide energy for activity, repair, and growth, keeping us healthy, and to keep our bodily functions strong. Although there are many nutrients, we divide them into two main groups:
1. Macronutrients: are the nutritive components of food that we need in larger quantities. They are fat, protein and carbohydrate. These three macronutrients are required for energy and to maintain the body’s structure and systems. All three macros contain calories (kcal):
1g of carbohydrate = 4kcal
1g of protein = 4kcal
1g of fat= 9kcal
2. Micronutrients: these are vitamins and minerals and are vital for our health but only needed in very small amounts. They do not contribute calories (energy) to the body.
Macronutrients
Carbohydrates
Carbohydrates (carbs) are the body’s preferred primary fuel. They provide energy for your muscles and the central nervous system (CNS) during movement and exercise. If you play high intensity repeated sprint sports (like rugby) you need to focus on carbs for fuelling your training session and matches. There are two main types of carbs, slow releasing (starchy/complex) carbs and fast releasing (sugary/simple). We want to focus on slow releasing carbs for the majority of our intake, to ensure we keep our blood sugars stable and have a constant release in energy throughout the day. However, at certain times, when we are aiming to perform at our best, consuming fast acting, sugary carbs will be to our advantage (this will be covered in a future article). Starchy carbs are also high in fibre, which is a vital nutrient for our health. In the UK the recommendation is 30g of fibre per day. The British Dietetic Association reported that the average fibre intake for adults is 18g per day, so only 60% of what it should be.
Slow Releasing Carbs: wholewheat pasta, wholegrain/basmati rice, cous-cous, wholewheat noodles, oats, lentils, quinoa, wholegrain bread, pitta breads, wholewheat bagels, wraps, sweet potatoes, beans, chickpeas.
Protein
The importance of protein seems to be well accepted among rugby players, with the use of protein supplements and foods skyrocketing in recent years. Protein is an essential nutrient, and although it may be only thought of in relation to muscle building, it is responsible for multiple physiological functions. Protein is the foundation for tissues, organs, cells, skin, and muscles. This macronutrient also makes up enzymes, hormones, and antibodies. At least 10,000 different proteins make you what you are and keep you that way.
Proteins are made up of building blocks called amino acids. There are twenty amino acids and our bodies make them in two different ways: either from scratch, or by manipulating other amino acids. Nine of the twenty amino acids (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine) are known as essential amino acids (EAA). We cannot make these EAA’s and so we must obtain them from food. Everyone needs protein in their diet, but if you are an athlete you will require a higher protein intake due to higher stresses placed on the body from training. For the general population the recommendation is about 0.8-1g per kilogram (kg) of body weight (BW). For rugby players it is 1.6-2g/kg of BW.
Recommended sources of protein: eggs, milk, yogurt, fish and seafood, chicken and turkey, soya, beans and pulses, lean beef, quinoa, nuts and seeds, oats, corn.
Fats
When it comes to fat in our diet, we must appreciate that not all fats are created equal. Some are incredibly nutritious and vital for our health. Others should be consumed minimally as they can cause adverse effects if overeaten for a prolonged period. Fat, much like carbohydrates and protein, are an essential nutrient. Your body needs fat for energy, to absorb vitamins, for insulation, and to protect your heart, brain, and other vital organs. They also act as messengers, helping proteins to carry out their role around the body, and are responsible for chemical reactions that control immune function, reproduction, growth, and other areas of metabolism.
There are two main types of fat: saturated and unsaturated. Most fat sources contain both types in different amounts.
Saturated fats, in comparison to unsaturated fats, negatively impact health by raising LDL (bad) cholesterol levels. High LDL levels puts you at risk of heart attack, stroke, and other major health problems. Saturated fats are best consumed in moderation. Foods containing large amounts of saturated fat include red meat, butter, cheese, cakes, biscuits, processed meats (sausages, bacon), pastries, chocolate, and ice cream. Some plant-based fats like coconut oil and palm oil are also rich in saturated fat.
Unsaturated fats (known as healthy, or essential fats) are subdivided into monounsaturated and polyunsaturated fats. They help lower risk for cardiovascular disease and overall mortality. Foods high in unsaturated fats include vegetable oils (such as olive, canola, sunflower, soy, and corn), avocado, most nuts, most seeds, and fish.
Micronutrients
Vitamins
Vitamins are organic compounds that our bodies need in small quantities to maintain normal cell function, growth, development, and optimal health. Most vitamins need to come from food because the body either does not produce them or produces very little of them. Each vitamin has an important role to play in the body. If you are not getting enough of a certain vitamin, a deficiency may occur, which can in turn cause health complications.
Vitamins are divided into two categories:
1) Fat-soluble vitamins are stored in the body's fat cells. The four fat-soluble vitamins are vitamins A, D, E, and K. These vitamins are absorbed more easily by the body in the presence of dietary fat. Another reason why fat is essential in our diet.
2) Water-soluble vitamins cannot be stored in the body. Any excess water-soluble vitamins are excreted in our urine. There are nine water-soluble vitamins, consisting of the B-vitamin group, and vitamin C. Although the body keeps a small reserve of these vitamins, they must be consumed on a regular basis to prevent deficiency in the body. Vitamin B12 is the only water-soluble vitamin that can be stored in the liver for a prolonged period of time.
Minerals
Minerals are inorganic substances and, like vitamins, are required by the body in small amounts for a variety of vital functions. Some minerals are required in larger amounts than others, e.g. calcium, magnesium, phosphorus, potassium, sodium, and chloride. Others are required in lesser quantities and are also known as trace minerals, e.g. iron, iodine, selenium, fluoride, and zinc. Despite being required in smaller amounts, trace minerals are just as essential as the other minerals.
To sum up...
To meet your requirements for the previously mentioned macro and micronutrients you should focus on eating a wide variety of vegetables, fruit, wholegrains, beans and pulses, lean meats and seafood, dairy, and, healthy fats. Although we can take supplements for some nutrients it is best to take a ‘food first’ approach to achieve your needs.