22 - Exercise and Intermediary Metabolism BCH3120 April 4,...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Exercise and Intermediary Metabolism BCH3120 April 4, 2011
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Introduction Exercise is… ± A unique stressor: unlike response of metabolic pathways to fasting and starvation, where there is adaptation, exercise can be an acute stressor. ± Example: Sprinting: net glycolytic flux in muscle increases at least 1000 fold within a few seconds or less. ± Example: Endurance exercise: whole body metabolic rate can increase 18-fold (over resting level).
Background image of page 2
Outline ± Types of exercise ± Intensity of exercise ± Metabolic regulation during anaerobic exercise ± Metabolic regulation during aerobic exercise ± Nervous system and cardiovascular responses ± Other hormonal responses ± Carbohydrate metabolism during endurance exercise ± Fat metabolism during endurance exercise
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Types of exercise ± Two general categories (which represent extremes): anaerobic and aerobic ± Anaerobic : e.g., sprinting; weight- lifting. ± Short duration ± Depends largely on activity of ‘fast- twitch’ (Type II) muscle fibers ± Rapid generation of energy in short time period ± Reliant on muscle’s own energy stores (phosphocreatine and glycogen),
Background image of page 4
± Aerobic : e.g., long-distance running; swimming; cycling; cross-country skiing ± Longer duration at lower intensity ± Reliant on the use of fuel stores from the rest of the body (e.g., adipose tissue TG; liver glycogen) ± Involves circulatory system ± Depends mostly on activity of ‘slow-twitch’ (Type I) muscle fibers ± ‘aerobic’ since substrates (fatty acids, glucose) are completely oxidized to maximize efficiency
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Intensity of exercise Terms and concepts: ± Force: strength of muscle contraction; units are in Newtons (N); equal to mass x acceleration. [1 N is about the forces required to hold an apple against gravity) ± Work: product of the distance moved and the force exerted; units in Joules (J) ± Energy: capacity to do work; units in J. [1 J is the work done when the force of 1 N acts over distance of 1 meter] ± Power: the rate of doing work; units in Watts (W). 1 W
Background image of page 6
External work done by the body is not the same thing as whole body energy expenditure (or metabolic rate) ± The body uses fuel to do external work, but the efficiency of fuel conversion into external work is only about 25%. About 75% of the fuel expended during work is converted into heat. ± Whole body energy expenditure = work done
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/18/2011 for the course BCH 3120 taught by Professor Mary-ellenharper during the Winter '11 term at University of Ottawa.

Page1 / 28

22 - Exercise and Intermediary Metabolism BCH3120 April 4,...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online