Metabolism part 2 (Exercise and Metabolic Responses)

Exercise will stimulate a series of metabolic responses that affect the body's anatomy, physiology, and biochemical make-up.

Aerobic System Changes: (Cardiovascular Training)

Aerobic training greatly increases the body's functional capacity to transport and use oxygen and to burn fatty acids during exercise. Some of the major changes measured as a result of aerobic exercise include:

• Increased mitochondria density in slow twitch muscle fiber, which results in higher energy production from fatty acids. Maximum oxidative capacity develops in all fiber types.
• Higher aerobic capacity.
• Increase in trained muscle capacity to utilize and mobilize fat, resulting from higher amounts of fat metabolizing enzymes, and increased blood flow.
• Greater development of slow twitch muscle fibers.
• Increased myoglobin, which is an iron-protein compound in muscle which acts to store and transport oxygen in the muscles.

Anaerobic System Changes: (Weight Training)

Anaerobic training greatly increases the body's functional capacity for development of explosive strength and maximization of short term energy systems. Some of the major changes measured as a result of anaerobic exercise include: 

• Increased size and number of fast twitch muscle fibers.
• Increased tolerance to higher levels of blood lactate.
• Increases in enzymes involved in the anaerobic phase of glucose breakdown (glycolysis).
• Increased muscle resting levels of ATP, CP, creatine, and glycogen content.
• Increased growth hormone and testosterone levels after short bouts (45 to 75 minutes) of high intensity weight training.