Energy Systems Glucose is the usual form of CHO used by animals including humans Stored in skeletal muscle and the liver as glycogen and broken down under stress (muscular activity) and transported by the blood to active sites Must be re-designed into free-energy ATP ATP – ADP+P+Energy When ATP breaks, the result in energy as a by-product Existing ATP is used up quickly, therefore in order to continue movement, the body must “reconstruct” the ATP molecule

Reconstruction takes place via two Energy systems previously discussed Anaerobic – without O 2 occurs within the muscle fibre using accessible enzymes and chemicals ATP-CP (ATP-PC) Glycolysis Aerobic – with O 2 more complicated, occurs inside the mitochondria Cellular respiration

ATP-CP – Anaerobic Alactic relies on phospho-creatine (readily accessible and stored in muscle) phosphate can easily be broken off allowing the formation of ATP PC+ADP→ATP+Energy+Creatine crucial in poweractivities such as sprints, weightlifting (not training) and high hump phospho-creatine depleted in seconds requires 2-5 minutes of recovery time and is replenished by ATP creation through aerobic processes therefore, the better the aerobic system works the shorter the recovery time

Glycolysis-Anaerobic Lactic glycolysis allows high energy outputs for 1-3 minutes glycogen is readily available in the body and it is during this stage that the partial breakdown of glycogen occurs in order to create ATP significantly more complicated the chemical reaction is C 6 H ADP+2P → 2C 3 H 6 O 3 +2ATP+2H 2 O Glucose Lactate the main product of glycolysis is pyruvic acid (pyruvate), this acid is the beginning of the aerobic system if enough oxygen is present where the complete breakdown of glycogen occurs in the absence of sufficient oxygen, the breakdown of glycogen is halted and pyruvate is converted to lactic acid

recovery from this is necessary to remove the burning sensation felt in the muscles as a result of the lactic acid buildup and takes up to two hours The Aerobic System any activities taking longer than 90 seconds require the utilization of cellular respiration at this stage, fats and proteins can be used as energy fats are burned almost exclusively in activities that last longer than 20 minutes and proteins are burned mostly in emergency situations such as starvation Chemical Equation for cellular respiration: C 6 H 12 O ADP +36P → 6CO ATP + 6 H 2 O Three separate pathways are used in order to achieve the complete breakdown of glucose in cellular respiration. Glycolysis, Krebs Cycle and the Electron Transport Chain

Lactic Acid the point at which lactic acid reaches levels significantly higher than those present at rest is referred to as blood lactate threshold or anaerobic threshold this level varies among individuals and lower thresholds suggest poorer functioning oxidative energy systems basically, untrained individuals have a lower blood lactate threshold than trained individuals trained athletes may not reach their threshold until around 70% of the VO2 max. while untrained individuals likely peak at 50% VO2 max. anaerobic or power training as well as aerobic training are critical in order to increase the threshold or onset of lactic avid buildup anaerobic training will extend the point of where buildup occurs, while aerobic training will improve the body’s ability to ‘flush’ or utilize lactic acid as an energy source in it’s eventual conversion to glucose and glycogen

Fat Energy fats contain 2+ times the amount of energy mass than CHO’s or proteins fatty acids used as energy sources are stored in the body as triglycerides and broken down by the process called lipolysis enter the energy systems at Kreb’s Cycle and are used almost exclusively in the Electron Transport Chain after being converted to Acteyl CoA through Oxidation with the mitochondria

Protein Energy similar potential as CHO, however the body does not store reserves of protein; all proteins within the body are of existing tissues comprised of about 20 amino acids, 9 of which must be consumed in food, they are converted to glycogen in liver used as energy source in endurance activities (primarily extreme) as the body draws upon these proteins in “short-term starvation” situations

Protein Supplements DO NOT – increase muscle mass automatically DO NOT – increase athletic ability ARE – given too much publicity ARE – potentially dangerous to the liver are not required in 90+% of North American diets Muscle Fibre Types Slow twitch – dark in colour relax/tension relatively slowly and are able to maintain this tension for long periods of time most useful in endurance activities Fast twitch – more pale than slow twitch relax/tension quickly and are able to generate large tensions for short periods Look at: pp. 86, 87 Page 90/92; Sprints, power activities Page 128, 133

Your lab 2 parts → 1/ % fat