• I am training – what and how much should I be eating?

    CI’m often asked this question by sprint and standard distance athletes that are following a structured training plan for the first time and also by iron distance athletes wanting to make sure that they are fuelling their training correctly. So, for both of these groups, the following article provides some basic information and sensible guidelines for you to follow.

    The Basics

    A healthy diet will enhance your training both in terms of providing good energy sources and assisting in recovery after training. In this article we are talking specifically about training for an endurance sport like swimming, running and cycling. For most of us training for health and for fun, our healthy training diet will be much the same as the healthy diet of our non-training neighbour. If you are a sprint or standard distance athlete following a varied diet you may not have to make any changes at all! For an iron distance athlete where training durations are generally longer closer attention needs to be paid to how much you are eating (i.e, ensuring you are getting enough calories in) and the composition of what you are eating.

    The body derives the energy it requires for exercise from carbohydrates, proteins and fats in our diet. Let’s look at each of these in turn.

    Carbohydrates

    During training the preferred fuel source of the body will be glucose that is stored as glycogen in your muscles. Glycogen comes from carbohydrates hence as a training athlete carbohydrates should be your most important food source. It is important to know that the store of carbohydrate in our body is relatively small so that we have to keep refuelling – topping up our glycogen tank – otherwise after a few days training you will begin to feel tired.

    Most of your carbohydrates should come from cereal and starchy sources like potatoes, pasta, rice, breads, breakfast cereals and starchy vegetables like sweet potatoes as well as peas and beans. A smaller portion of carbohydrates could come from fruits.

    Carbohydrates and the Glycaemic Index

    When it comes to training and to performance you also need to think about how quickly your carbohydrate fuel is going to be converted into glucose so that it can be used as your energy source. Sometimes we want the food to give us energy right now (or as quick as possible) and at other times we want the food to give us a gentle stream of energy over a longer period of time. This is what the Glycaemic Index (GI) of a food will tell us. Carbohydrate-rich foods with a moderate to high GI like bagels, breads, rice, bananas and raisins are an excellent choice of food when you need to refuel quickly after exercise.

    Proteins

    Protein in our diet is primarily used for the growth and repair of our muscles. Any protein that we do not need for these functions will either be used for energy or be stored as fat or carbohydrate. Proteins are made up of amino acids. Our bodies are unable to produce 9 amino acids – the essential amino acids – so these must be included in our diet. Foods that contain all the required essential amino acids are called “the complete protein” foods and include yoghurt, eggs, fish, meat and chicken.

    Fat

    The primary function of fat in the diet is to provide the body with a back up energy source – something to fall back on when glycogen is low.

    And while it is generally accepted that as a population we should be cutting back on our fat intake , we do need some fat in our diets to provide us with essential fatty acids (Omega 3 and Omega 6) and the fat soluble vitamins – A, D, E and K. Good sources of these fatty acids include oily fish such as salmon and mackerel, walnuts, seeds and sweet potato.

    Vitamins and Minerals

    Training in itself does not increase the need for additional vitamins and minerals. If you eat a healthy, varied and balanced diet that provides you with the energy requirements for your training then you should be getting all the vitamins and minerals that you need.

    Putting it all together – guidelines for eating for endurance training

    Make carbohydrates the focus of your training diet
    Fuel your training and recovery (covered in a later section) – ensure that you are eating enough to provide the energy for your training but do not eat more than you need!
    Eat a wide variety of foods and include 5 portions of fruit and vegetables a day
    Eat two portions of fish a week one of which should be an oily fish
    Eat less fat and replace saturated fat with unsaturated fat
    Avoid processed foods where possible – if you have to read the label don’t buy it.
    Drink coffee and alcohol in moderation or not at all!

    So how much should I be eating?

    Training for and endurance events in sessions of 1-2 hours per day, for most athletes, will require 5-7g carbohydrate per kilogram body. (Within this range there will be individual variability depending on the intensity of training and also variability in the way in which the body metabolizes sugars and carbohydrates.)

    What about during exercise?

    The muscles store sufficient glycogen to fuel most athletes for around 90 mins of moderate exercise so the good news is that during a session of less than 90 mins you will not usually need to eat anything to keep you going (although you will need to hydrate). If training for longer than this or training at higher intensity you will need to take on additional fuel and this could be in the form of endurance sport specific bars, gels and drinks.

    Carbohydrate needs during exercise are estimated to be 1 -1.1g per min, or 60-66g per hour for most athletes (depending on how hard you are working). As an example, if you were a cyclist riding moderately for 2.5 hours then, to maintain your energy, you could have a gel containing 30 g of carbohydrate after 1.5 hours and then another after 2 hours. Everyone is different though so practice during any longer sessions to see what and how much is going to work best for you.

    And after training?

    You can enhance recovery and adaptation processes (this is where you get stronger) by replenishing your carbohydrate and protein stores as soon as possible after training. It has been shown that uptake of glycogen back into the muscles is optimized during the first hour after training so it is important to take on recovery fuel within this window. There are plenty of sports specific recovery drinks on the market but a glass of milk (skimmed is fine!) after training is just as effective as commercially bought products. Other good options would be chicken or tuna sandwich on wholemeal bread or similar.

    Food for thought

    The science of sports nutrition has developed rapidly over the last decade and there is now much more information and detail available. For most of us, following these basic guidelines will serve us very well as we develop our fitness and reach for our endurance goals.