Carbohydrates and Energy Levels
Healthy Carbohydrate Choices
What happens if your athlete does not Consume enough Carbohydrate?
If the carbohydrates you eat do not provide you with enough energy, your body quite literally breaks down protein-rich tissues to provide you with energy for exercise. Therefore, like a low protein diet the initial effect of low carbohydrate diet can lead to decrease in performance output, muscle wastage accompanied by increasing weakness and chronic fatigue, brittle hair and nails, pale skin and headaches (common within eating disorders in sport).
Risk of infections may increase due to lack of antibodies produced, and athletes may become increasingly irritable and develop skin rashes.
Psychological effect: Some athletes become emotional or mentally irritable, this could include crankiness, moodiness, problems with conflict resolution, depression, anxiety and lack of energy or desire to do anything.
Daily Carbohydrate Requirements
The most important goal of an athletes diet is to ensure that their everyday diet provides the muscles with substrates to fuel the training programme that will achieve optimal adaptation and performance adaptation (Burke et al, 2004). As stated, carbohydrates provide the major sources of exercise fuel, with carbohydrate sources coming from plasma glucose derived from the liver or dietary carbohydrate uptake, and muscle glycogen stores. Limited glycogen stores have been shown to be an inhibiting factor in high intensity intermittent exercise such as boxing.
Low Intensity /Moderate Int
5 - 7g / kg / bw
Pre Event Meal
1.4g / kg / bw /
1-4 hours pre competition
Moderate to Heavy Training
7 - 10g / kg / bw
Rapid Post Bout Recovery:
Another Bout The Next Day
1.0 - 1.2g / kg / bw /
Daily Recovery: Extreme Exercise Programme
10 - 12g / kg / bw
Immediate Recovery Post Exercise (4 hours)
1.2g / kg / bw / hour
(Burke et al, 2004., Campbell and Spano, 2011)
The Glycaemic Index: What type of carbohydrate should Boxers Consume and is There an Optimal Time to Eat Them?
Fitness Components of Boxing
Boxers must be able to react quickly to an opponent, therefore both the aerobic and anaerobic energy systems are required during a bout.
According to Bompa and Carrera (2005) the dominant energy systems are the aerobic (50%), lactic acid (40%), and alactic (10%), with glycogen and creatine phosphate been the energy sourced.
Bumpa and Carrera (2005) lists the main limiting factors within boxing as:
Muscular Endurance of Medium Duration
Muscular Endurance of Long Duration
To calculate what type of carbohydrates you need to be consuming, you first have to be aware of the demands of the sport. This will enable to you plan your diet around energy and recovery levels to optimise performance.
Traditionally, carbohydrates are broken down to two groups, simple and complex. These terms simply refer to the number of sugar units in the molecule. What is important for sports performance is how quickly the carbohydrate is ingested from the small intestine to the bloodstream. The faster this transfer, the faster the food can be used as energy by the muscle cells, thus making a difference to training and recovery (Bean, 2007).
However, it is tempting to think that simple carbohydrates lead to a sharp rise in blood sugar over a short period of time. However, this is not always the case
for example, apples contain simple carbohydrates but produce a small rise in blood sugar over a long period of time. Whereas, many starchy foods such as potatoes and bread, are digested and absorbed very quickly and give a rapid rise in blood sugar.
The Glycaemic Index (GI) ranks foods from 0 to 100 based on their immediate effect on blood sugar levels, thus measures the speed your body can digest food and convert it to glucose. The faster the rise in blood sugar the higher the rating.
Pre-workout meals should consist of low GI based on the theory that it will provide a sustained energy source during exercise. Depending on duration and intensity of training, you would want to consume either water to hydrate or a maximum of 30-60g carbohydrate solution to maintain performance. After exercise, carbohydrate is important to replenish glycogen stores and can be done via a combination of both simple and complex carbohydrates.
Bean, A (2007) A complete Guide to Sports Nutrition. A C Black Publishers.
Bompa, T,O., and Carrera, M,C., (2005) Periodisation Training for Sports: Science based strength and conditioning plans for 20 sports. Human Kinetics.
Burke, L, Kiens, B and Ivy, J (2004) Carbohydrates and Fats for Training and Recovery. Journal of Sport Science. 22. 15 - 30
Campbell B.I and Spano, M.A (2011) NSCA's Guide to Sport and Exercise Nutrition. National Strength and Conditioning Association.