Energy Ace Flashcards
Very little of the __________ a person consumes is used for energy production.
Of the three macronutrients, relatively little protein is used for energy production except in extreme cases of caloric restriction. Protein is principally used in the growth and repair of tissue or is excreted.
Yes or No.
Low-intensity exercise is the best way to lose weight because it burns a higher percentage of fat than exercise at a higher intensity.
No.
During high-intensity exercise, the total number of calories burned is much higher than during low-intensity exercise, and negates the higher percentage coming from fat. During low-intensity bouts, a higher percentage of calories is coming from fat, but the total number of fat calories is less than during high-intensity workouts. It is important to remember that the total number of calories burned is what determines weight loss, regardless of the source of those calories.
During high-intensity workouts, when there is inadequate oxygen, pyruvate converts into _______________.
If exercise intensity is very high and adequate amounts of oxygen are not available, pyruvate can be converted into lactate, which may be transported out of the active cell and used for energy by other cells in the body. This allows for the continued production of pyruvate via anaerobic glycolysis, resulting in a steady supply of ATP.
Beta oxidation is a result of _______________.
Beta oxidation, also called fatty acid oxidation, occurs within the mitochondria and is an aerobic pathway that breaks down fatty acids to produce ATP.
Aerobic glycolysis occurs in the cells’ _______________, and anaerobic glycolysis occurs in the cells’ _______________.
Aerobic glycolysis is a metabolic pathway that occurs within highly specialized cell structures called the mitochondria, which are often called the powerhouses of the cell. Anaerobic glycolysis occurs within the cytoplasm of the cell and involves the incomplete breakdown of glucose to a simpler substance called pyruvate.
_______________ is the primary nutrient utilized during high-intensity exercise.
Compared to fatty-acid metabolism, glucose metabolism requires less oxygen, so the body will use more glucose and less fat for energy production as exercise intensity increases. The respiratory exchange ratio is a marker of the proportion of fat or carbohydrate that is being used for fuel at different exercise intensities. At higher intensities, carbohydrate becomes the primary source of fuel.
Oxidative glycolysis occurs as a result of sufficient _______________ in the mitochondria.
Oxidative glycolysis, which occurs within the mitochondria, is limited mainly by the capacity of the cardiorespiratory system to deliver oxygen to the active cells.
Blood glucose is efficient in fueling _______________ exercise, whereas muscle glycogen is more efficient in fueling _______________ exercise.
Blood glucose plays a greater role in energy metabolism during low-intensity exercise, as the body’s ability to deliver glucose is comparable to the rate of glucose utilization. However, muscle glycogen is the primary source of carbohydrate during high-intensity exercise, as the rate of glucose utilization far exceeds the rate of glucose delivery.
During the first hour of a half-marathon, carbohydrate metabolism is fueled by _______________.
During the first hour of submaximal endurance exercise, such as a half-marathon, much of the carbohydrate metabolized by muscle comes from muscle glycogen.
During low-intensity exercise, _______________ is/are the primary source of fat energy.
During low-intensity exercise, plasma free fatty acids are the primary source of fat energy. Furthermore, as the duration of the exercise increases, there is a progressive rise in the role of plasma free fatty acids as a fuel source.
