Carbohydrate (CHO) is important as an exercise fuel. Having enough fuel to supply the body is essential to be able to perform optimally and combat fatigue or tiredness, which could lead to injuries. Carbohydrate can come in the form of solids and liquids. In some cases we need to have more than just plain water to help us exercise, concentrate or perform optimally. Sports drinks, sports gels or juices can help us achieve this.

Would you run your car optimally and a certain distance without having the correct fuel for your engine and it adequately filled?

Carbohydrate ingestion for performance should be planned according to activity, the level of activity, training regime, and individual requirements. Carbohydrate intake is important as moderate to high intensity exercise for longer than an hour requires the metabolism to convert the fuel to energy and is dependent on the cardiovascular systems ability to deliver to the muscle the adequate oxygen and food. We need CHO to perform optimally and to give us fuel.

When do we take Carbohydrate liquid for exercise?

• If there is not a short turnaround time between the exercise sessions there is not a requirement to intake CHO as soon as possible after the activity in liquid form.
• If the exercise sessions are less than 8 hours apart then intake of Carbohydrate as soon as possible will improve recovery but can be achieved with solids such as fruit, yoghurt, rice, cereal, and potato.
• Simple CHO such as fruit, yoghurt, and syrup can be used for quick refueling within the first 4 hours after a session.
• If duration of exercise is longer than an hour then liquid form carbohydrate can be taken to maintain blood glucose and improve endurance performance. This is particular beneficial in day tournaments or competition.
• For 80minute bouts of exercise or over both CHO gels and sport drinks maintain blood glucose levels during exercise and improve performance when compared to just pure water. TIP: Refuel at halftime or at breaks in play. If running for long endurance periods use gels and grab carbohydrate drinks at the organised stations.
• Liquid CHO should be used when required during an intermittent exercise activity to replenish glycogen stores and water at other times. Tip: Mix when Intermittent.

Meals and Snacking during Exercise:

• High intensity sports such as rugby, hockey, squash, football of 45-75min duration require small amounts of CHO ingestion, including mouth rinsing, for enhancement of performance via the central nervous system. TIP: Mouth rinse for performance benefits with Sports isotonic drink.
• Should there be an increase in intensity or length of a particular session, then ingesting things such as jellybeans has been shown to positively affect performance. A little amount would suffice.
• During exercise, glycogen stores will become depleted and the quickest method to restore these levels is through the use of simple CHO. Simple carbohydrates are found naturally in foods such as fruits, milk, and milk products. They are also found in processed and refined sugars such as sugar, candy, syrups, and soft drinks. The use of these must be balanced against gastrointestinal comfort for the individual as the nutritional benefits may be offset by discomfort during exercise. Tip: Aware of stomach pains

It is always essential to ascertain the amount of exercise undertaken, specifically with respect of the intensity and mode. Over-reaching syndrome symptoms with a higher dietary CHO intake can be reduced. This would optimize the outcome of training and overall performance. 
The consequence of following a low CHO diet, even for 1-3 days whilst continuing to exercise, can include the lowering of resting muscle and liver glycogen stores, which in turn can reduce exercise capacity and increase fatigue. Following a higher CHO diet can improve training performance, delay fatigue, and improve power output.

References

Achten, J., Halson, S., Mosely, L., Rayson, M.P., Casey, A., & Jeukendrup, A.E. (2003. Effect of diet on symptoms of overeaching in runners during a period of intensified training. Medicine of Science in Sports and Exercise. 35(suppl.), S211.
Burke, L,M. (2010). Fueling strategies to optimize performance: training high or training low? Canadian Journal of Medicine and Science in Sports. 20 (suppl. 2), 48-58. 
Burke, L, M., Hawley, J.A., Wong, S.H., & Jeukendrup, A.E. (2011). Carbohydrates for training and competition. Journal of Sports Science. 29 (Suppl.), S17-27.
Burke, L.M., Kiens, B., & Ivy, J.L. (2004). Carbohydrate and fat for training and recovery. Journal of Sports Science. 22, 15-30.
Campbell, C., Prince, D., Braun, M., Applegate, E., & Casazza, G.A. (2008). Carbohydrate-supplement form and exercise performance. International journal of Sport Nutrition and Exercise Metabolism. 18, 179-190.
Foskett, A., Williams, C., Boobis, l., & Tsintzas, K. (2008). Carbohydrate availability and muscle energy metabolism during intermittent running. Medicine and Science in Sports and Exercise. 40(1), 96-103.
Jeukendrup, A.E. (2008). Carbohydrate feeding during exercise. European Journal of Sports Science. 8(2), 77-86. 
Roberts, S.P., Stokes, K.A., Trewartha, G., Doyle, J., Hogben, P., & Thompson, D. (2010). Effects of carbohydrate and caffeine ingestion on performance during a rugby union simulation protocol. Journal of Sports Science. 28(8), 833-842.
Schroder, S., Fischer, A., Vock, C., Bohme, M., Schmelzer, C., Dopner, M., Hulsmann, O., Doring, F. (2008). Nutrition concepts for elite distance runners based on macronutrient and energy expenditure. Journal of Athletic Training. 43(5), 489-504.