Muscle Sugar: Train Low and Compete High
I came across the following via Dr. Gabe Mirkin's Fitness and Health E-Zine January 9, 2011 and wondered what the gang here thought and if is reasonable how would it be best implimented in the OS.
Muscles use carbohydrates, fats and proteins for energy. You can improve both endurance and speed in athletic competitions lasting more than a couple hours by training your muscles to burn more sugar and less protein and fat during competition.
The most efficient fuel for muscles during exercise is carbohydrates (sugar). The limiting factor for how fast you can move is the time it takes to move oxygen into muscles. Since sugar requires less oxygen than protein or fat, you move faster when your muscles burn primarily sugar.
How far you can run, cycle, ski, or skate depends on how much sugar you can store in your muscles before you start exercising and how long you can keep the extra sugar there. When muscles run out of their stored sugar, muscles hurt and you feel tired.
ADVANTAGES OF TRAINING ON DEPLETED GLYCOGEN
You can teach your muscles to burn more sugar and less fat by starting some of your workouts with muscles that are low in their stored sugar, called glycogen. This forces muscles to burn a higher percentage of fat. However, muscles move faster when they use sugar for fuel, so they try to burn more sugar. They increase the concentration of the many enzymes that help to convert sugar to energy. This allows muscles to burn a higher percentage of sugar during competition so athletes can go faster and improve their chances of winning.
WAYS TO DEPLETE MUSCLE GLYCOGEN
You can start your workouts with low muscle glycogen by:
*training after skipping breakfast;
*training twice a day, so your muscles have low stored sugar during your second workout of the day;
*restricting carbohydrates in your diet during training;
*taking prolonged workouts that empty your muscles of stored sugar, or *withholding carbohydrates after a hard workout.
The key is to train with low amounts of stored muscle sugar and race with muscles full of stored sugar (Exercise and Sports Science Reviews, October 2010).
HOW TO INCREASE SUGAR-BURNING ENZYMES IN MUSCLES
You can't start all your training workouts with low muscle sugar because it will slow you down, reduce the amount of miles you can do in training, and increase your chances of injuring yourself.
Knowledgeable athletes train by stressing and recovering. They take a hard workout on one day, feel sore on the next, and then take easier workouts until the soreness disappears. They do very intense workouts up to three times a week, rarely on consecutive days. These intense workouts should be taken with muscles full of sugar, so you should eat before your intense workouts and even take sugar during the workout.
However, on your four recovery days, try starting your workouts without eating breakfast. If you feel excess fatigue, your muscles hurt or you have little energy, shorten your workouts and immediately eat extra carbohydrates such as fruits, vegetables, whole grains, beans, and even whole grain bread or pasta.
If you find that you are fatigued too often and take too long to recover from workouts, abandon this training technique. It is not for you. You probably have to take in a lot of sugar during training just to keep up the intensity and volume of work that is required to be a competitive athlete.
WHAT TO DO BEFORE COMPETITION
Hundreds of research papers show that you can increase endurance and intensity in competition by filling your muscles with sugar before you compete and then taking sugar during competition. Athletes in endurance events should cut back on their training three days before major competitions and eat extra carbohydrates. This fills their muscles with extra sugar. They should eat a high-carbohydrate breakfast and take sugar during the competition to keep up a regular sugar supply for their muscles.
Comments
I have heard a lot about this but haven't had time to dig into the research due to grad school. There is a big sports nutrition conference in March in Chicago. I have heard that this is going to be a topic of discussion (I'm expecting this one to get heated). One of the big sports nutrition researchers is going to present some new research showing this doesn't work. I'm not sure about the "hundreds of research papers" comments. I'd suggest searching pubmed to see if that is true or asking him for a list of citations (put up or shut up about it).
That said, everyone is different. If you want to try it, try it in training before RR#1 and see what happens.
Early in my marathoning I found Gu and how much it helped me on long runs – mostly in a mental way. As I fatigued physically (low blood sugar from depleted glycogen??) I would begin to get irritable, my mojo would evaporate and I would loose the ability to do simple math. My brain seemed to be revolting from lack of food.
Pumping Gu in at 5 mile ~ 45 minute intervals helped tremendously. I got so I could tell the early warning signs and Gu-up. About a mile later my mental function would return to normal and I’d avoid the brain bonk. I began to rely heavily on Gu for that reason.
After a while I realized I was becoming Gu dependant. Anytime my head went south, I would NEED to Gu. Without it I would suddenly stop running and walk, or worse, just stand there – and my mental state was so week I couldn’t fight it. Then I read something about not using Gu too early in a training run and to try to use less than seemed necessary. The purpose was to teach the body to be more dependant on fat metabolism, less dependant on ingested calories, and more efficient with glycogen stores. I tried that method and it has helped me a lot on long runs and races (I do Gu regularly in races).
On training runs I still bring enough Gu (1 per 5 miles) but I don’t use it unless forced to. I find I have better fatigue tolerance now. Meaning when I start to mental-bonk, I can still maintain my pace until things really get bad. Now it is uncommon to use Gu on any run shorter than 16 miles and I usually do well up to the last mile or so. On a 20+ mile run I will start Gu after about 10 miles or so and try to go 6-7 miles between shots. The exception would be on days I really struggle. On those days I will use as needed. I do carry Gu ‘just in case’ on most runs. I just try to minimize its use.
In summary, I see functional utility in carb-starving the body to maintain or enhance fat metabolism systems during long training efforts. But I cannot see intentionally depriving the body of vital nutrition prior to the workout. That just doesn’t make any sense to me.
Just my 2 cents – But remember - I don’t have any letters after my name, nor do I work in the medical, nutrition or fitness fields…….
@Steve: That's the key. Each person has to find what works for him/her and do it. If you do what the "authorities" or "professionals" say and it doesn't work, then don't do it and find something that does.