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This chapter explores the basic chemical processes involved in energy production for muscular activity, including the breakdown of carbohydrates, fats, and proteins. It delves into the ATP cycle and the three main energy systems in the body. The role of training and exercise on these systems is also discussed.
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Energy for Muscular Activity Chapter 5 Sport Books Publisher
Learning Objectives: • To develop an awareness of the basic chemical processes the body uses to produce energy in the muscles • To develop an understanding of the body’s three main energy systems • To introduce the effect of training and exercise on the energy systems Sport Books Publisher
Breakdown of Energy currency Biochemical processes Carbohydrates Muscular Work ATP Thermoregulation Fats Digesting Food Proteins The Chemistry of Energy Production • Energy in the human body is derived from the breakdown of complex nutrients like carbohydrates, fats, and proteins • The end result of this breakdown is production of the adenosine triphosphate (ATP) molecule • ATP provides energy necessary for body functions Sport Books Publisher
ATP Cycle Overview a) ATP breakdown b) Phosphorylation c) ATP resynthesis Sport Books Publisher
+ Pi ATP + H2O ADP + Energy 2. Phosphate molecule (Pi) is released from ATP (ATP ADP) a) ATP breakdown (ATP turnover) 1. Hydrolysis of the unstable phosphate groups of ATP molecule by H2O 3. Energy is released (38 to 42 kJ, or 9 to 10 kcal/mol ATP) Sport Books Publisher
Molecule + Pi b) Phosphorylation Energy for muscle contraction 1. Energy released by ATP turnover can be used by body when a free Pi group is transferred to another molecule (phosphorylation) Sport Books Publisher
+ Pi ADP + Energy ATP c) ATP resynthesis • Initial stores of ATP in the muscles are used up • very quickly and ATP must be regenerated 2. ATP is formed by recombination of ADP and Pi 3. Regeneration of ATP requires energy (from breakdown of food molecules) Sport Books Publisher
High energy phosphate system b) Anaerobic glycolytic system c) Aerobic oxidative system The Energy Systems Sport Books Publisher
The Roles of the Three Energy Systems in Competitive Sport Sport Books Publisher
1. The High Energy Phosphate System Sport Books Publisher
Primary energy source: Stored ATP, CP Duration of activity: 7 to 12 s Weightlifting, high jump, long jump, 100 m run, 25 m swim Sporting events: Produces very large amount of energy in a short amount of time Advantages: Initial concentration of high energy phosphates (ATP, PC) Limiting factors: High Energy Phosphate System Overview Sport Books Publisher
ENERGY Creatine P High Energy Phosphate System ADP + Pi ATP Sport Books Publisher