Aerobic Systems Fat & Carbohydrate for fuel.
The Aerobic System
The aerobic breakdown of carbohydrates, fats, and proteins provides substrates for a continuous restoration of the limited phosphogen pool. It is phosphogen energy which fuels all levels of muscular activity. It is the relative percentage of maximal capacity contributed by the aerobic pathway that varies with intensity and duration of work. At rest, all energy is aerobic because the phosphogens used to write, talk, eat, and breathe are continuously replaced by the aerobic metabolism of nutrients. The intensity is very low and the duration can be very long, in fact until food nutrients are depleted.
OTS Notes on 5- Metabolic Levels by Exercise Intensity:
Level 1 is fueled by 60% Fat and 40% Carbohydrate- runs up to 65% of Max Heart Rate
Level 2 is fueled by 50% Fat and 50% Carbohydrate- runs at approximately 70-75% of Max Heart Rate
Level 3 is fueled by 35% Fat and 65% Carbohydrate- runs at approximately 75-80% of Max Hear Rate
Level 4 is fueled by 10-20% Fat and 80-90% Carbohydrate- runs at approximately 80-90% of Max Heart Rate
Level 5 is Phosphogen based, short sprints 5-30 seconds in duration. 0% Fat.
Most muscle has enough phosphogen stored for about 30 seconds of sustained muscular contractions. These are replaced mostly via the aerobic metabolic pathways.
Important concepts of the Aerobic system follow:
1. Individuals can sustain all out efforts demanding maximal aerobic capacity for only 8-10 minutes because lactic acid is rapidly accumulating to provide addition energy.
2. Except for short all out efforts, aerobic processes are continuously providing energy at rates ranging from very low to the individuals maximum.
3. Aerobic energy production occurs whether we are asleep or at maximum exercise capacity. This has led to some confusion on how to train for this system.
4. It is commonly believed that once past the anaerobic threshold, all energy comes from lactic acid production. This is NOT true!
5. Research shows that the basic external loading factors of frequency and duration or program length is determined by individual fitness levels, and the greatest gains in maximal aerobic capacity occur when exercise intensity is at levels requiring 90-100% of maximal capacity (VO2 max).
6. The percent improvements or absolute gains are actually lower when training intensities are supramaximal or greater than 100% of VO2 max. At the other end of the scale, minimum stimulus required to achieve any improvement appears to be tasks requiring 50% of maximal aerobic capacity.
7. The magnitude of increase in maximal capacity is usually inversely related to initial capacity. Poorly conditioned individuals attain the greatest increases with appropriate training. It is difficult for highly trained athletes to quantify any improvement in VO2 max. For these individuals, measured values may be limited by heredity rather than by the volume or intensity of training.
8. Greater improvements in highly conditioned athletes can be seen in their anaerobic capacities, economy of effort, and fractionalization (fractional utilization) of maximum capacity during competitive events.
9. When athletes start training, a laboratory or field test to quantify variables other than just VO2max should be conducted.
10. The traditional method for improving aerobic capacity has been to form an early season aerobic base by numerous long distance workouts in the weekly schedule (microcycle). These are generally continuous and moderate intensity and become less frequent and of shorter duration as the annual cycle moves into competitive stages.
How can knowing the 3 energy systems and 5- Metabolic levels of exercise help you to design a week of workouts?
How can knowing your energy systems and the fuel subsrates that support them help you to design your nutrition.