Introduction
Nutrition can be a complex topic and I do not want to make it sound more complex than it needs to be, especially when it can be kept simple! For that reason I approach all articles in the same manner and this will be no different.
First I will address the issue at hand, second I will provide some context and background information and lastly I will provide the solutions to address the issue at hand.
The Issue
With many GAA clubs returning to championship football and hurling over the coming weeks, todays topic will be of particular interest.
The issue that I will address today is the use of pre-match nutrition protocols and in particular, carbohydrate loading for a game. The most common issues that presents with this are:
The person solely focuses on increasing carbohydrate intake on the day of the game
They disregard nutrition in the day/s prior to the game.
They do not know how much they need to consume.
They do not know what foods to avoid.
They do not know what foods to prioritise.
They do not respect the timing of intakes.
If you are waiting until game day to increase carbohydrate intake you are arriving very late to the party. Alongside this, large intakes of certain foods can be a cause of gastrointestinal discomfort on the day of a game which can really hamper performance.
It has been known for decades that carbohydrate is essential for performance, observations in the early 1900s showed that low levels of carbohydrate intake and the onset of low blood glucose levels play a major role in the development of fatigue. In the second half of the 1900s the use of muscle biopsies by Bergstrom et al., (1966,67) was able to further confirm that exercise depletes muscle glycogen stores and that higher carbohydrate diets were linked with higher muscle glycogen stored.
These observations lead to practices of pre-exercise consumption of carbohydrate to offset these performance decrements and fatigue. This is a practice that still holds true today, albeit the recommendations have changed since the creation of the initial protocols.
Here is a big caveat with all of this as you already probably know that carbs are important. But it is pretty useless for you to know the importance of carbohydrate for performance when you do not know how to put the information into practice. Therefore it is imperative that we know the 3 T’s of the nutrition protocol you will use. The 3 T’s refer to the total, time and type of food we consume.
Today’s article will address two questions:
What is the role of carbohydrate
How should you structure your intakes to maximise your match day performance
Background Context
Carbohydrate is a highly important fuel source during exercise, especially during high-intensity, repeat bout exercise when oxidative metabolism cannot meet the demands of the exercise.
Having adequate carbohydrate availability is vital to fuelling performance and delaying the onset of fatigue and maintaining high performance levels. Carbohydrate availability refers to total amount of carbohydrate available as substrate at a given point in time and it is dependent on the total amount of carbohydrate taken in through the diet and the total amount expended.
If you are taking part in regular high intensity exercise, carbohydrate stores need to be replenished in order to recovery between exercise bouts. However, given most people train exhaustively quite regularly, they never achieve full restoration of carbohydrate stores between exercise bouts. That being said it is okay as they do not need to be fully restored all of the time as the demands do not always require such high levels.
Carbohydrate is readily stored in our muscles as glycogen and the typical person has the ability to store 400g of carbohydrate (larger muscles would mean a larger capacity to store glycogen). The amount stored at any point in time will very according to activity levels and diet composition.
Glycogen is also stored in our liver and this store is much smaller than our muscles, with approximately 80 to 100 grams. After an overnight fast (sleeping), liver glycogen depletes to around 20 grams as the brain used it up while we rest. This highlights the importance of carbohydrate intakes in the morning to replenish these stores.
The glycogen in the liver plays a major role in regulating blood glucose levels during exercise and at rest. Liver glycogen is broken down to glucose and it is then transported in blood to the target tissues. Like muscle glycogen, liver glycogen stores will change throughout the day in accordance to activity and food consumption. When blood glucose levels drop during exercise there is an increase in the breakdown of liver glycogen in order to maintain blood glucose homeostasis. Blood glucose is tightly regulated however it can drop to unwanted low levels when stores are low which will impair performance.
The rate of glycogen use during exercise is largely determined by the exercise intensity. At low exercise intensities, both carbohydrate and fat can be oxidised in order to fuel the demands but as exercise intensity increases, oxidation of fat and carbohydrate cannot meet the energetic demands. Anaerobic energy processes then dominate and muscle glycogen becomes the main source of energy.
At very high intensities the breakdown down muscle glycogen occurs rapidly. In sports where high intensity running is performed in an intermittent fashion, like football and hurling, a high carbohydrate availability prior to exercise is essential.
If muscle glycogen stores are low prior to exercise there is an increased dependence on the liver to breakdown liver glycogen and circulate it to the target tissues. Therefore if you do not store enough carbohydrate before beginning exercise, you will fatigue quicker.
Conversely, when liver glycogen is low, there is an increase need for liver glycogen to maintain blood glucose levels to compensate for the increased glucose uptake by the muscles. Again, highlighting the importance for consuming adequate carbohydrate prior to exercise.
Low glycogen concentrations will have a detrimental effect on your ability to meet the physical and physiological demands of match play due to glycogen being the main energy substrate utilised by skeletal muscle during periods of high-intensity activity (Burke et al., 2011).
Decreases in running metrics, such as total distance, high-speed running distance and sprint distance will occur when playing under conditions of low glycogen availability compared to high glycogen availability (Balsom et al., 1999; Holway 2011; Malone et al., 2017). Cognitive function, reaction times and awareness can also decrease when stores deplete. Research has already shown that Gaelic football players do not consume adequate carbohydrate in the days prior to competition in order to meet the demands of the game. It was shown that they consume less than 4 grams per kg of body mass which is likely to be sub-optimal (Cassidy et al., 2018; Cathain et al., 2020).
With that being said, it is rather obvious that increase carbohydrate availability would be a top priority leading into a game! But how should you go about this?
The Solutions
Traditionally, a carbohydrate loading protocol would be a very drawn out process beginning with an exhaustive bout of exercise, followed by a high fat, high protein diet for 3 days which is then followed by a 3 day high carbohydrate diet. This protocol leads to some issues, such as gastrointestinal distress, mood disturbances and tenseness/anxiousness (as a result of no exercise all week). Another big issue was the practicality of the protocol and its applicability to a given sport.
Within certain realms, people would traditionally eat large amounts of carbohydrate food sources on the day of a game and again this does not come free of problems. Many people also suffer from gastrointestinal discomfort as a result of the sheer volume of food and the type of food they try to consume.
The traditional models are not suitable for field sport athletes and the protocols are not necessary. Thankfully there are simpler guidelines that can be followed to maximise glycogen stores, continue training on the week of the match and not have you consuming insane volumes of food beyond that required.
#1 Pre and Post Training Carbohydrate Intake
Without calling it a loading protocol, I would advise the following for guidelines for pre and post training sessions (and not just in the week leading to a game but most weeks), especially in-season when high performance is the goal. In the off-season or pre-season I would periodically include some sessions with low-carbohydrate availability but only for sessions of low intensity as this can confer a positive adaptation.
Total
Pre-training consume a serving of 1 to 1.2 grams of carbohydrate per kg of body mass.
Post-training consume a serving of 1 to 1.2 grams of carbohydrate per kg of body mass.
Timing
Pre-training: 3 to 4 hours pre to allow for digestion and absorption to occur and to lessen the chance of tummy distress.
Post-training: as soon as practical and when relaxed, preferably in the first hour to maximise the use of rapid-phase glycogen repletion. There is a heightened response to carbohydrate intake and glycogen synthesis following exercise which restores muscle and liver glycogen quicker.
Type
Pre-training: Carbohydrates that are moderate to high on the glycaemic index such as white bread, oats, potatoes, bananas, white pasta, white rice, fruit juice, canned fruit, honey. Avoid high fat foods as they slow the rate of gastric emptying.
Post-training liquids are generally better tolerated soon after so smoothies and liquids are a good option. A maltodextrin powder is ideal for this. Then in the hour after a solid food source can be used. Use the same examples as the pre but add in the option of cereals.
Why?
Simply following these guidelines will help to ensure that glycogen levels are not drastically depleted throughout the week and that recovery from training is prioritised. If intakes are not prioritised with each session that goes by the total amount of glycogen available will lower until a large amount of carbohydrate is consumed. This will lessen the burden of the nutritional demands on game-day-1 as you will have already been prioritising glycogen repletion through the week.
#2 Game-Day-1
Game-day-1 refers to the day prior to a game. On this day you want to maximise carbohydrate intake in order to ensure that your muscle glycogen stores are replenished and relatively full. If you placed adequate priority on pre and post training nutrition then you will be able to consume less total carbohydrate than someone who hasn’t.
Total: The total amount of carbohydrate that you want to consume on this day is between 6 and 10 grams of carbohydrate per kg of body mass. For example an 80g person with a 6g/kg target would require 6X80 = 480 grams of carbohydrate.
The lower level is applicable to those who prioritised nutrition through the week and the higher level for those who didn’t. The levels also represent the size of the individual with those having large muscle mass requiring more. It is difficult to provide exact guidelines as a result of these nuances.
Timing: The timing of intakes should be spread out in 4 to 5 servings through the day for convenience and practicality.
Type: A low residue diet is preferred. Lower residue will mean lowering fruit and vegetable intake and favouring of lower-fibre carbohydrates that are moderate to high on the glycaemic index such as white bread, oats, potatoes, bananas, white pasta, white rice, fruit juice, canned fruit, honey.
Other Nutrients: Protein intake can be kept normal at between 1.2 and 2 grams of protein per kg of body mass while fat intake can be lowered to around 0.8 grams of fat per kg of body mass.
#3 Game-Day Nutrition
By following the prior two examples, the burden to consume large amounts of food on game day is lowered as muscle glycogen stores will be high as result or eating habits from the preceding days.
The main goal of the game day breakfast or meals is to top up liver glycogen as it will be depleted after an overnight fast and depending on the length of time until the game some additional glycogen may end up being stored in the muscles which is another win.
Your game day breakfast should be lighter as you do not want have that heavy feeling in the tummy, especially if the game is early afternoon. You really only want to satisfy hunger levels and limit the chance of incurring any tummy distress during the game. If the game is later in the day then a large breakfast followed by a smaller lunch and dinner would be preferable.
The game day breakfast should aim to include between 100 and 300 grams of carbohydrate depending on the duration between the meal and the game and the individual. If it is earlier this can be lower and if it is later it can be higher.
For digestive preference, by limiting food volume, liquid sources of carbohydrate coupled with solid forms can be more favourable. Examples would include an overnight oats/bircher muesli, toast and jam washed down with a large glass of orange juice.
Foods or nutrients to avoid in large quantities on game day are fibre in large amounts and fatty foods. If using milks use low fat/skimmed versions, the same goes with yoghurts. If eating carbohydrate foods use the white versions like white bread.
It must also be said that personal preference on game day is very important. Being comfortable with your own choices will ease any anxiousness and radical change is not warranted. My advice would be to prioritise the week prior and day prior to game day so that you can enjoy your food on the game-day without having to be questioning food choice more.
Attached to this is two sample meal plans, one suitable for game-day-1 and one for game day.
References
Malone, S.; Solan, B.; Collins, K. The running performance profile of elite Gaelic football match-play. J. Strength Cond. Res. 2017, 31, 30–36.
Balsom, P.D.; Wood, K.; Olsson, P.; Ekblom, B. Carbohydrate intake and multiple sprint sports: With special reference to football (soccer). Int. J. Sports Med. 1999, 20, 48–52
Holway, F.E.; Spriet, L.L. Sport-specific nutrition: Practical strategies for team sports. J. Sports Sci. 2011, 29, S115–S125. [CrossRef]
Cassidy, C.; Collins, K.; Shortall, M. The precompetition macronutrient intake of elite Gaelic football players. Int. J. Sport Nutr. Exerc. Metab. 2018, 28, 574–579
Catháin, C.Ó.; Fleming, J.; Renard, M.; Kelly, D.T. Dietary intake of Gaelic football players during game preparation and recovery. Sports 2020,
Louise M. Burke, John A. Hawley, Stephen H. S. Wong & Asker E. Jeukendrup (2011): Carbohydrates for training and competition, Journal of Sports Sciences, 29:sup1, S17-S27
Thank you to Ronan for this insightful piece which really highlights the clear advantages that can be attained through appropriate pre game nutritional strategies.
Ronan O'Brien is a Sport Scientist, come Performance Nutritionist based in Dubai. He has his own coaching business called Feeding Movement which has been growing from strength to strength since beginning in 2018. You can find him Instagram as @feedingmovement. He works with a wide range of populations from general population to elite athletes. He offers both in-person and online coaching services.