The Body Builders Paradox
As a bodybuilder who relies heavily on muscle energy, one of the worst things you can do is let your glycogen levels get to low or become depleted. In fact, Dr. Susan M. Kleiner who has worked as a nutritional consultant for the Cleveland Brown reminds us that during high-intensity strength training reps lasting only for 1 to 3 minutes, that muscle glycogen supplies about 95% of the fuel (energy) needed to complete this set. Equally, as cited by Dr. Kleiner the more carbohydrate left in the muscle at the end of a session, the longer you will be able to continue. While the body can’t store protein, glucose, your muscle’s primary energy source can be. In fact stored glucose known as glycogen is stored in the liver and in muscle tissue and is called upon when insufficient amounts of carbohydrates are consumed. Normally the muscles can store about 1,200 calories of glycogen and the liver and about 400 calories of glycogen. This is why researchers contend that to maintain muscle energy and to keep glycogen stores replenished that carbs need to be consumed before, during and at post-workout. In fact, the two well-known sports physiologist John Ivy and Robert Portman authors of The Performance Zone states that the greatest performance benefits have been found to occur when 50g-70 g of carbs are consumed per hour of exercise to restore diminished glycogen stores .
What The Research Tells Us
In studies conducted at the University of Texas researchers found subjects who adhered to carbohydrate supplementation were able to exercise for 3 hours at a highly charged rate at 80% VO2 max ( maximal oxygen uptake) for 33 minutes as compared to 2 minutes by subjects who were administered flavored water. These researchers attributed this to carbohydrates ability to spare muscle glycogen. In a related study appearing in the Journal of Sports Science and Medicine investigators reported that muscle glycogen synthesis was more rapid when carbohydrates were consumed immediately following exercise as opposed to waiting hours later. If fact, these researchers found that when subjects delayed carbohydrate intake for several hours the rate of glycogen creation was reduced by 50%. Furthermore, recent data indicates that when carbohydrate supplementation occurs at 15 to 30 minute intervals rather than every 2 hours that muscle glycogen storage has been found to be 30% higher.
Moreover, Dr. Liz Applegate, a faculty member of the Department of Nutrition at the University of California and a Fellow of the American College of Sports Medicine reminds us that studies show when some form of carbohydrate is consumed ½ hour before working out can extended workout time and workload capacity, delaying what is commonly referred to as hitting the wall. Conversely, research conducted at Appalachian State University suggest that enhancing glycogen storage via carbohydrate supplementation heightens immunity. For example, marathon runners were given 60 grams of carbohydrates at a rate of 1 liter per hour. These researchers found increased activity of key cells involved with immune preservation. Other studies indicate that maintaining adequate glycogen stores reduces muscle wasting by minimizing the production of cortisol. The more glycogen levels fall, the faster cortisol is released from the adrenal glands, with one purpose in mind, the breakdown of muscle protein for fuel. On the contrary, when glycogen levels increase brain and mental fatigue is greatly delayed.
The Protein Carb Connection
It is common knowledge that carbs with protein at post workout helps drive insulin into the muscle to speed recovery. The other aspect of this biological attribute not highly publicized shows that combining protein with carbs within 30 minutes of exercise increases glycogen storage. However, the ratio must be 4:1, (4g of carbs to 1g of protein). The problem here is the fact that higher protein ratio intake slows rehydration and glycogen replenishment. However, data indicates that when carbs and protein are consumed in the above ratio’s that there is a 100% greater storage of glycogen than consuming carbs alone.
Suggested Dose: to gauge your individual carb needs based on you, researchers suggest consuming 3g to 5g of carbs for every pound of your body weight. While current data indicates that most physically active people’s diet should be 60% to 65%, carbs, resistance training athletes may need a little more.