Ironmate - Mark Kleanthous

Energy for Endurance.
Endurance training causes improvement in the ability to generate energy (movement) from stored fat.
The type of training required is often neglected because of a misunderstanding of how much fat is used during racing such as the marathon and the ironman.
We release fuel for energy from carbohydrate or fat or a combination of both.
1. Muscles and liver have a limited amount of stored carbohydrate know as glycogen.
2. Carbohydrate from energy gels sports drinks and foods before or during exercise.
3. Energy can also come from within the muscles and stored fat hips and tummy etc.
What you need to know?
Taking in calories will only allow us to work at 30-60% of our capacity (this is a wide range and depends on too many factors to be discussed in this article) so we therefore need to also use fat as a second source of energy. Similar to a hybrid car that uses electric and fuel but normally uses one or the other and sometimes both.
If we were able to just use ingested food then the athlete who could work the hardest at the same time eating as much as possible should go the fastest.
To be successful in an endurance event we need to be efficient using all three types of energy available listed above.
Carbohydrate is our best source of fuel because we can also work at very high levels, the problem is we have limited stores up to 2,500 calories and can be less than 1,000 calories in a semi fatigued state. 2,000-2,500 calories will keep us going at a high intensity just below our anaerobic threshold for up to 2 hours hence hitting the wall at around 2 hours in a marathon.
Most age group athletes have similar VO2 max values so the one that finishes first is usually the one with the best ability to use fat for energy saving their carbohydrate stores for later in the competition and who has paced more evenly.
Nutrition requirements should be a balance between carbohydrate protein and fat.
Training should be 90% of easy steady training so you become the best you can at using fuel efficiently. You can improve this part of your fitness considerably compared to your VO2 max.