Sport Books Publisher1 Energy for Muscular Activity Chapter 7

Sport Books Publisher2 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 Publisher3 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 Carbohydrates Fats Proteins ATP Muscular Work Digesting Food Thermoregulation Breakdown ofEnergy currencyBiochemical processes

Sport Books Publisher4 ATP Cycle Overview a) ATP breakdown b) Phosphorylation c) ATP resynthesis

Sport Books Publisher5 1. Hydrolysis of the unstable phosphate groups of ATP molecule by H 2 O 3. Energy is released (38 to 42 kJ, or 9 to 10 kcal/mol ATP) ATP H2OH2O+Energy+PiPi+ 2. Phosphate molecule (P i ) is released from ATP (ATP ADP) ADP a) ATP breakdown (ATP turnover)

Sport Books Publisher6 1. Energy released by ATP turnover can be used by body when a free P i group is transferred to another molecule (phosphorylation) Energy for muscle contraction Molecule PiPi+ b) Phosphorylation

Sport Books Publisher7 1.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 P i ATP ADP Energy+PiPi+ 3. Regeneration of ATP requires energy (from breakdown of food molecules) c) ATP resynthesis

Sport Books Publisher8 The Energy Systems a)High energy phosphate system b) A naerobic glycolytic system c) A erobic oxidative system

Sport Books Publisher9 The Roles of the Three Energy Systems in Competitive Sport

Sport Books Publisher10

Sport Books Publisher11 High Energy Phosphate System Overview Primary energy source: Duration of activity: Sporting events: Advantages: Limiting factors: Stored ATP, CP 7 to 12 s Weightlifting, high jump, long jump, 100 m run, 25 m swim Produces very large amount of energy in a short amount of time Initial concentration of high energy phosphates (ATP, PC)

Sport Books Publisher12 High Energy Phosphate System Creatine P P ENERGY ADP + P i  ATP

Sport Books Publisher13 Training the High Energy Phosphate System a) Interval training: - 20 percent increase in CP (creatine phosphate) stores - no change in ATP stores - increase in ATPase function (ATP  ADP + P i ) - increase in CPK (creatine phosphokinase) function (CPK breaks down CP molecule and allows ATP resynthesis) b) Sprint training: - increase in CP stores up to 40 percent percent increase in resting ATP stores