The Simple Truth About Athletic Nutrition

In order to perform at their peak, athletes must master the self discipline necessary to select the correct foods at the appropriate time. To fuel the human body, just like anything else, it is the quality and timing

Insulin promotes the uptake of sugar, amino acids, and fats from the blood into the cell. Insulin is the only hormone to lower blood sugar, while five other hormones raise blood sugar. During exercise, delivery of glucose to the central nervous system is a critical priority. The CNS needs fuel in order to execute the complex tasks involved in moving the human body through space, or lifting a weight, making a jump, etc. Athletic performance requires a healthy brain not unlike a student taking a test.

If we begin an exercise or strenuous event with high insulin, the following negative effects quickly occur. First, because exercise increases our sensitiviy to insulin via muscle contraction, glucose is removed from the bloodstream very quickly. So quickly in fact that the drop in blood sugar creates a depressed central nervous system. Starting an exercise with high insulin might cause symptoms like fatigue, head ache, nausea, etc. after warming up. This is due to lack of fuel delivery to the brain and disruption of neural networks needed for high performance activity.

Secondly, when our blood sugar is low and unstable, we suffer all kinds of emotional and performance-reducing symptoms. Why is it that climbing a mountain is less risky than decending, with more accidents happening on the decent than the climb itself? The reason has to do with blood sugar, and as we lose our ability to balance our fuel sources, our blood sugar declines which causes a reduction in brain function. Loss of brain function will impair judgement, slow reaction time, and essentially depress the nervous system. These are risk factors for accidents.

Third, high insulin inhibits the body’s ability to burn fat. Fat happens to be the main energy source during prolonged exercise, endurance events, etc. and it provides the majority of ATP to fuel the aerobic energy cycles. Loss of the ability to burn fat for energy will more quickly deplete a muscle’s store of glycogen and will result in increased fatigue. Insulin slows down the systems we depend on for sustained energy during exercise

According to current research, eating low-glycemic meals creates higher athletic performance. This makes sense because high blood sugar causes high insulin which causes negative effects during exercise. We don’t want insulin to be high, we want growth hormone, glucagon, and other catabolic hormones to be high. This will assure that our body is burning fat and glycogen stores producing stable blood sugar to fuel our body. Exercising with high insulin is like trying to drive forward and reverse at the same time.

The only time high glycemic foods are appropriate is when there is less than 24 hours of recovery time between events. Only then it is alright to eat pastas, breads, carbohydrates, etc. in excess because they will increase glycogen stores faster. However, low glycemic meals will also replenish glycogen stores as long as you are eating adequate amounts of fruits and vegetables. The take away is that for the vast majority of our athletes, eating low glycemic meals pre and post workout is a more effective way to improve performance because it helps to balance our endocrine response to the stress of exercise.

As long as insulin and blood sugar are not spiked, the body will release free fatty acids from fat storage and these molecules will be delivered to cells to be burnt for energy. They will be burnt in the citric acid cyle inside mitochondria mainly in the heart, skeletal muscle, and liver. This provides our body with hours of energy in the form of ATP.

The citric acid cycle needs amino acids to work at full speed. Without enough amino acids present in the cell, the citric acid cycle will slow down. This means less energy for the body. By ingesting protein 30-45 minutes before exercise, we are making sure the cells have adequate amino acids available. Whey protein is best because it has high levels of branched chain amino acids (BCAA) which are the preferred form for energy production.

Ingesting protein 0-30 minutes after exercise also helps prevent muscle breakdown and leads to a slight increase in muscle formation. Proteins are the building blocks of muscle tissue. When we don’t have enough protein the exercise causes muscles to be broken down and they become less healthy. The cells need protein after exercise to rebuild enzymes, cell structures, and damaged muscle. Cortisol also causes protein breakdown after heavy exercise. BCAA block the negative effects of cortisol on our muscles and prevent the body from breaking down its own tissues. BCAA’s lead to faster recovery, larger glycogen stores, more strength, and more endurance.

Take supplement and protein shakes after working out within 30 minutes. The body is primed for absorbing these important nutrients and getting them in your body quicker will assure a rapid repair process and an increase in performance.

There is a time and a place for ingesting glucose and carbohydrates. During prolonged exercise, after 30 minutes or so of effort glucose can be taken in moderate quantities. By waiting until 30 min of exercise has passed before eating or drinking sugar the body is allowed to turn on its long term aerobic energy systems. Sugar is only appropriate once the event has started and at the end of workouts under most circumstances.

So as a rule of thumb if you are running a marathon you take carbohydrate:protein in a 4:1 ratio after the event has started (remember to warm up without high blood sugar and high insulin). If your event is more power and strength focused the ratio shifts 2:1 and if you are a body builder you might be using a carbohydrate:protein ration of 1:1. Everyone needs protein and everyone needs sugar, just adjust the ratio depending on your event.

Yours in Health,

Dr. Andrew