Fuel for Endurance
Fuel for endurance is a hotly debated topic. Understanding your bodies energy and nutritional requirements is a difficult task. Fueling this demand can be even trickier. As an endurance athlete I am constantly researching and experimenting with new and old training techniques. I believe fuel along with physical/mental strength, flexibility and recovery are all components of a good training lifestyle. Endurance athletes have traditionally favoured diets high in carbohydrates (pasta, bread, rice, potatoes etc.), moderate in protein (meat, fish) and low in fat.
Simple Carb Absorption
When you eat carbohydrates, they are converted into glucose and released into the blood stream. This triggers a release of insulin from the pancreas. Insulin helps regulate blood sugar concentration by storing excess glucose in the form of glycogen. Too much sugar/carbohydrate in the blood stream can have a negative effect. Some of this glucose is used straight away and sent to the various muscles and brain to meet energy requirements. The rest is sent to the liver and skeletal muscle to be stored as glycogen. When glycogen stores are full, the glucose is stored as fat.
Traditional Fuelling Approach
Typically an endurance athlete would take a high to moderate glycemic index (GI) food before training or an event and then consume another high GI food (to restock glycogen stores) after training or an event, followed by low GI food with protein in their main meal. Healthy snacks would be consumed about every few hours with water or a replacement drink close to hand at all times. The reasoning behind this is that you need to replenish your glycogen stores and regenerate the muscle fibres you have stressed.
The two main systems an endurance athlete uses while training and racing is the aerobic and anaerobic systems. The degree to which you use these depends on you training, what you use to fuel your body and how hard you train. The aerobic system is fuelled predominantly by your fat stores with some glucose used as kindling. The anaerobic system is fuelled by glucose from carbohydrates. Therefore if you train anaerobically you need to fuel yourself with carbohydrates.
Most of us want PB’s and come from a culture of “train hard race hard”. We are always pushing the boundaries of our current abilities so as to improve. This inevitably leads us to push into our anaerobic zone. The drawback to this is that we can only store a couple of hours of glycogen in our body while at a low to moderate intensity and hence have to keep refuelling. If we don’t refuel enough we run out and hit the wall. Having to constantly think and stress of refuelling as well as losing time undertaking refuelling is tiresome. Another problem is that carbohydrates don’t agree with everyone.
But what if you didn’t need to use carbohydrates to fuel you? Research has shown that we need only a small amount of carbohydrates, just enough to enable us to burn fat efficiently. It is also believed that the source of this carbohydrate can be supplied from whole unprocessed foods like vegetables, nuts and pulses.
What if you stayed aerobic and used your fat stores to fuel your efforts. We can store a lot more fat than glycogen. Could we run as fast while staying aerobic? Is it possible to train the aerobic system to go faster? This is what I hope to find out. I am going to blog a series of updates on the effects of this approach on my endurance training. In my following post I will explain of how I came across this philosophy and the logic behind it.