1. Exercise Physiology Step 2: Sports Dietetics

3. 1. Energy Storage

6. Where is fuel stored? Adapted from Mcardle, Katch, and Katch. Sports and Exercise Nutrition. Lippincott, Williams & Wilkins, 2005 Muscle : ATP, PCr, Glycogen, IMTG, Carbons from AAs Mitochondria Liver : Glycogen -> Glucose AAs Blood : Glucose FFA Deaminated AAs Adipose Tissue : TG FA

7. Where is fuel stored? Adapted from Mcardle, Katch, and Katch. Sports and Exercise Nutrition. Lippincott, Williams & Wilkins, 2005 Muscle : ATP, PCr, Glycogen, IMTG, Carbons from AAs Mitochondria Liver : Glycogen -> Glucose AAs Blood : Glucose FFA Deaminated AAs Adipose Tissue : TG FA ATP

9. 2. Energy Metabolism, Substrate Utilization, & Oxygen Transport

11. ATP Production from… Phosphocreatine Carbohydrate Fat 10 seconds 1-3 minutes w/o Oxygen Long, requires Oxygen FAST ATP > 60 minutes w/ Oxygen SLOW ATP Short, quick, powerful Higher intensity Low intensity Runs out of gas fast Gas is expensive & limiting Gas is cheap, never runs out, speed cap

12. ATP Production from… Phosphocreatine Carbohydrate Fat 10 seconds 1-3 minutes w/o Oxygen Long, requires Oxygen FAST ATP > 60 minutes w/ Oxygen SLOW ATP Short, quick, powerful Higher intensity Low intensity Runs out of gas fast Gas is expensive & limiting Gas is cheap, never runs out, speed cap 2 ATP 38 ATP 500 ATP

15. Rate of ATP Synthesis by Different Energy Systems References: Miller, W. The Biochemistry of Exercise and Metabolic Adaptation. Brown and Benchmark, 1992 Maughan, R and Burke, L. Sports Nutrition: Handbook of Sports Medicine and Science. Blackwell Science, 2002. ≈ 20 Fat Oxidation ≈ 200 Anaerobic Glycolysis ≈ 450 Phosphocreatine Breakdown µmol per minute per gram of muscle

17. Fuel utilization depends on EXERCISE DURATION Exercise at Constant Intensity % CONTRIBUTION Crossover Concept

18. Fuel utilization depends on EXERCISE INTENSITY % CONTRIBUTION REST LOW TO MODERATE HARD EXERCISE EXERCISE FAT CARBS PROTEIN

20. Anaerobic Glycolysis GLYCOLYSIS KREBS CYCLE Glycogen Cytoplasm Glucose is starting point and when oxygen is not present, pyruvate is endpoint. Muscle glycogen enters Glycolysis at G-6-P, skipping first step. NADH + H Pyruvate Acetyl-CoA Mitochondria (Krebs Cycle = TCA Cycle = Citric Acid Cycle) Glucose Glucose-6-Phosphate ATP ×

21. Anaerobic Glycolysis GLYCOLYSIS KREBS CYCLE Glycogen Cytoplasm Glucose is starting point and when oxygen is not present, pyruvate is endpoint. Muscle glycogen enters Glycolysis at G-6-P, skipping first step. When H atoms are produced more rapidly than NADH and ETC can process, lactate is formed. NADH + H Pyruvate Acetyl-CoA Mitochondria (Krebs Cycle = TCA Cycle = Citric Acid Cycle) Glucose Glucose-6-Phosphate ATP × Lactate

25. Aerobic System: Carbs GLYCOLYSIS KREBS CYCLE Glycogen Cytoplasm NADH + H Pyruvate Acetyl-CoA Mitochondria Glucose Glucose-6-Phosphate ATP Oxygen H H H H H H H ATP With oxygen present, pyruvate is converted to Acetyl-CoA and into Krebs Cycle.

26. Aerobic System: Carbs GLYCOLYSIS KREBS CYCLE Glycogen Cytoplasm NADH + H Pyruvate Acetyl-CoA Mitochondria Glucose Glucose-6-Phosphate ATP Oxygen H H H H H H H ATP Hydrogen generated from glycolysis and Krebs Cycle enter Electron Transport Chain. ELECTRON TRANSPORT CHAIN

28. Aerobic System: Fat GLYCOLYSIS KREBS CYCLE Cytoplasm Pyruvate Acetyl-CoA Mitochondria Glucose Oxygen ATP E FA FA FA glycerol Triglyceride Beta-oxidation : FA, which are 16-24 carbons long, are broken down to Acetyl-CoA (2 carbons), fatty acid activation are slow

29. Aerobic System: Fat GLYCOLYSIS KREBS CYCLE Cytoplasm Pyruvate Acetyl-CoA Mitochondria Glucose Oxygen E FA FA FA glycerol Triglyceride Breakdown of TG : Yields lots of carbons, lots of hydrogens, and lots of ATP…460! H H H

46. 3. Enzymes & Hormones

52. 4. Response to Training

54. 5. Fatigue