Concept questions

Fuels

What are the 3 macronutrients and their fundamental characteristics? Which are used for energy? What are the muscle and blood fuel sources respectively? What is the relationship between exercise intensity and… Use of fat? Use of carbs? What is the relationship between muscle glycogen and exercise intensity? What effect does that have on muscle glycogen and performance during exercise? Describe the 2 different ways in which the liver produces glucose. How do these processes change with increased exercise intensity? Which one contributes more glucose at high intensity? Does glucose uptake increase or decrease with increase exercise intensity?Can muscle glycogen be transported?Is there more lipid or carb storage in muscles?What is the recommended daily protein intake?What is the relationship between lipolysis and insulin?

Review

Fuels for Exercise, Energy Transfer· Macronutrients (CHO, fat, protein)· Fuels used during exercise o NOTE: think CHO vs. fat; think muscle fuel vs. blood-borne o NOTE: be sure to understand the relative contribution of CHO and fat as exercise intensity increases· Carbohydrate metabolism during exercise: o REMEMBER: ATP levels remain constant during exercise (i.e. synthesis = breakdown) o Glycolysis § Key enzymes (phosphorylase, PFK, PDH): · NOTE: think about how these enzymes are regulated § Blood glucose · QUESTION: how does glycogenolysis and gluconeogenesis contribute to blood glucose concentration as exercise time increases? · Fat metabolism during exercise: o Lipolysis (TG = glycerol + 3-FFA) § Key regulators: catecholamines such as epinephrine § QUESTION: What happens to lipolysis from rest to exercise? Moreover, what is responsible for this change (think about the relative effect of regulators such as catecholamines and insulin)· Protein o Made of amino acids (ex: hormones, enzymes, transporters, etc.). o Anabolism vs. Catabolism o Protein as a fuel? § Glucose from other by-products § Alanine-glucose cycle