EXAM II REVIEW 1. Define postabsorptive and postprandial states and explain how each of the macronutrients is absorbed into the system. a. Postabsorptive State – Time after the body has been fasting after meal is absorbed. Blood glucose is maintained by glycogenolysis and gluconeogenesis in the liver. i. Glycogenolysis – (Glycogen to Glucose) provides 65-75% of blood glucose ii. Gluconeogenesis – (formation of glucose) provides 25-35% of blood glucose b. Postprandial State – time right after a meal i. Glycolysis – forming glucose from meal ii. Glucose is absorbed and stored as glycogen (glycogenesis) in skeletal muscle and liver iii. Adipose Tissue – removes glucose to form glycerol and makes triglycerides for fatty acids 2. Which hormones control blood glucose and how? How does exercise influence these responses? a. Insulin – lower blood glucose by storing – i. Decreases with exercise b. Glucagon – increase blood glucose – i. Increases with exercise c. Norepinephrine & Epinephrine – increases blood glucose – i. Increases with exercise 3. What factors influence CHO use during exercise and how? a. Intensity – Higher Intensity depletes glycogen storage faster b. Duration – correlates with Intensity – longer/less intense c. Initial Glycogen Levels – Higher Glycogen Storage = longer/harder workout d. Training Status – Better training utilizes more FAT to produce energy 4. What is the recommended timing for the feeding of CHO before exercise? a. 30-60min before – works better for heavy intensity versus moderate i. Rebound Hypoglycemia ii. Increased CHO catabolism/reduced fat mobilization iii. Conserve liver glycogen b. 3hr or more before i. Studies show both improved performance, and no effect5. What are the general guidelines for a pre-competition meal? a. 150-300g CHO (3-5g/kg) b. Solid or liquid c. Relatively little fat or fiber d. Limit protein e. Glycemic Index i. High = higher initial blood glucose ii. Low = endurance was longer 6. When is it most beneficial to feed CHO during exercise? What are the guidelines? a. When exercise is longer than 1 hour long at 20min intervals b. ~2% glucose drink. i. Too high concentration of glucose causes GI distress 7. How does CHO feeding during recovery influence muscle glycogen? a. CHO feeding during recovery increases the amount glycogen synthesis, however over longer period of time (8hr), regular glycogen synthesis is the same. 8. What factors enhance glycogen synthesis and how? a. Timing – Early is better i. I-Form glycogen synthase ii. Insulin is high iii. Glut-4 is high from exercise b. Type of Carb – Glucose & Sucrose is synthesis better than fructose c. Amount – Med/High intake is better (0.7-1.4g/kg) d. Presence of other Nutrients - no significant difference between PRO/CHO mix and CHO e. Exercise Type – i. Eccentric Exercise – Cause more muscle soreness/damage & reduces glycogen synthesis 1. Damaged sarcolemma/inference of glucose transport 2. Inflammatory response utilizing glucose f. Subsequent Performance – High Carb diet increase power output versus low carb diet 9. Know the recovery feeding guidelines for enhancing muscle glycogen storage. a. 1.0-1.5g/kg CHO each hr for the first 4hrs after exercise b. High GI foods or simple carbs c. Carb replenishing drink (70-90g) if unable to eat d. Early Feeding (High CHO) for quick recovery i. Benefits Daily Exercisers10. How does muscle damage influence glycogen resynthesis? a. See Above: Exercise Type 11. What are the guidelines for daily CHO intake? a. Low intensity, moderate duration – 5-7g/kg Carb b. Moderate/Heavy intensity endurance – 12g/kg Carb c. Extreme exercise (4-6hrs) – 10-12g/kg Carb 12. How is performance (daily, moderate and high intensity) influenced by CHO intake? a. Daily – High Carb diets help promote better performance b. Moderate Intensity – relies between FAT and CHO energy sources c. High Intensity – relies heavily on muscle glycogen and blood glucose, so proper CHO intake is crucial 13. What are the differences between the classic and taper techniques for CHO loading? a. Classic – Exercised to exhaustion and were on a low carb diet for 3 days before a high carb diet. b. Taper – Slowly increased Carb intake while decreasing exercise getting closer to competition 14. How does CHO loading affect glycogen and performance? a. Both Classic and Taper show High Glycogen storage, however performance and amount of glycogen post-race wasn’t significant i. 3g water stored for every 1g CHO, equals more weight and work15. Understand the multiple variations possible in defining fatty acids. a. Essentialiy – a-linolenic acid (Omega-3) and linolenic acid (Omega-6) i. Immune fuction, vision, cell membrane, hormone production b. Chain Length - # of carbon molecules i. Short – less than 6 carbon length ii. Medium – 6-12 carbon length iii. Long – 14 or more carbon length c. Degree of Saturation - # of double bonds i. Saturated – no double bonds ii. Monounsaturated – 1 double bond iii. Polyunsaturated – 2 or more double bonds d. Shape – Double bond in cis (bend) or trans (straight) formation i. 16. What effect does hydrogenation have on fatty acids? a. Adds hydrogen to unsaturated bonds i. Raises melting point (more solid) ii. Less susceptible to rancidity (decomposition of fats) 17. Identify the sources and contribution of fat used by muscles for energy production. a. Adipose Tissue i. FFA hydrolyzed by HSL (rate-limiting enzyme) b. Muscle Triglycerides i. Adipocytes between fibers ii. Lipid droplets in fibers c. Blood Triglycerides i. Chylomicrons ii. Serum triglycerides 18. What factors influence the mobilization of fatty acids? a. Exercise, Caffeine, Carnitine, and High-Fat Diet (See #22)19. How do the muscles obtain and utilize the fatty acids for energy production? a. Fat Metabolism i. Lipolysis – breakdown of triglycerides to fatty acids and glycerol ii. Lipogenesis – formation of triglycerides from fatty acids and glycerol iii. Beta Oxidation – breakdown of fatty acids to acetyl CoA for entry into Krebs Cycle iv. Fatty Acid synthesis – formation of new fatty acids b. Sources: i. Adipose Tissue – FFA – Major source ii. Muscle Triglycerides – adipocytes between fibers, and lipid droplets in fibers (5-35% of FFA supply) iii. Blood Triglycerides – Chylomicrons &