It's no secret that endurance athletes love their carbs, and no denying that carbohydrate is the best energy source for endurance athletes. It's something of a love affair, and it's been going on for a very long time. After all, carbohydrate is the athlete's main fuel source. If you eat the right amount, it increases the amount of glycogen stored in your liver and muscles meaning you will be able to train longer and harder, it keeps blood glucose levels high during exercise which helps delay fatigue, and taken after exercise it helps you to recover faster by replacing glycogen lost from the muscles and liver. Plus it's in most of our food and it tastes pretty good too. What athlete wouldn't love it?
But there is an underdog in this love story. The ever-humble protein. Long-touted to be in the domain of strength and power training athletes (such as body-builders), protein has often been dismissed by the endurance athlete as something that isn't beneficial for them, because the goal of the endurance athlete does not include building large amounts of muscle. However, protein performs a different function for endurance athletes than it does for strength athletes. When protein is overlooked by endurance athletes, it can lead to a negative effect on performance. As an endurance athlete, to perform at your best you need to eat your carbs, and your protein too.
Why do I need protein too?
Your body needs protein to grow and develop and maintain strong muscles and tissues, repair damage done to muscles and tissues during exercise, transport oxygen around the body and keep your immune system at optimum function. In a strength athlete, protein is used by the body for increased tissue-repair. In an endurance athlete, the body needs protein to maintain aerobic metabolism, and repair muscle damage caused by exercise such as cycling, running or swimming. Endurance athletes, who do longer periods of intense exercise, will use protein as a source of approximately 5 – 10 % of the energy they expend while exercising, especially if muscle glycogen stores are depleted, which occurs after approximately 90 minutes of moderate exercise. When protein is being used for energy, it is unable to carry out the other functions it performs in the body. Since protein is not stored in the body, humans need to eat enough protein every day. If an endurance athlete does not eat enough protein to support the exercise they do, then lean muscle tissue will be sacrificed by the body during training sessions to give the body the fuel it needs to keep going, a process called Gluconeogenesis.
How much protein should I eat?
The normal protein intake for a sedentary adult is 0.8 – 1 gram per kilogram of body weight per day. For an endurance athlete, this rises to 1.2 – 1.4 g/kg /day and for a strength athlete it is 1.6 – 1.7 g/kg/day.
Example: A cyclist who weighs 80 kilograms would work out their protein needs as follows:
80 (kg) x 1.2 (g/kg) = 96g of protein. For 1.4 g/kg this increases to 112 grams of protein.
So an 80kg cyclist in training would eat 96 – 112 grams of protein per day.
Do I need protein supplements?
You may be thinking 'Great, now I know I'm supposed to eat protein, so I'll go stock up on the supplements." There are lots of protein supplements on the market, and the nutritional content of them varies greatly. I'm not saying that supplements aren't useful, but you need to recognise what you are consuming and the reason for that before you head to the shops. In most cases, the protein that you need comes straight from your food, and if you supplement without knowing what you need, then you can end up eating far too much per day. Athletes, and this includes strength athletes as well as endurance athletes, should be careful to balance carbohydrate and protein in their diet. If a protein supplement is used, it is often to replace protein at the end of a workout.
Supplements can be quick and easy, but make sure you know what you are doing before using them. It is actually possible to eat too much protein. Various studies suggest that the maximum usable amount of protein per kg/day is 2 grams. Any more than this and not only will you see no improvement, but you risk not eating enough carbohydrate to meet your energy needs. You also place extra strain on your kidneys as your body produces more urine to get rid of the waste products from the extra protein, and your body will store more fat. Extra kilojoules, no matter what source of food they come from will be stored as fat if the body doesn't need them, and also many high protein foods are also high in fat, which your body doesn't need.
When working out your protein intake, make sure you check how much protein is actually in the food you are eating. Many people assume that 50grams of lean, cooked meat would contain 50 grams of protein, because meat is associated as being a 'protein' food. In actual fact, a 50g portion would contain around 15 grams of protein. Other examples of food containing 15 grams of protein include 50g canned tuna, 2 large eggs, ½ cup hummus or 400mls milk. Every food sold in New Zealand must be labelled with its nutritional content. Your job, as an athlete, is to know what foods you need to eat, how much of each food you should have, and make sure you eat it. Work out what you are going to eat in advance, and split your food into manageable portions. Don't forget that you should consume protein after each training session to help repair damage to the muscles. Around 10 – 20 grams is recommended.
By Kristy Clarkson
The information in this article is necessarily general and not meant to replace advice from your medical professional.