We noted you are experiencing viewing problems
-
Check with your IT department that JWPlatform, JWPlayer and Amazon AWS & CloudFront are not being blocked by your network. The relevant domains are *.jwplatform.com, *.jwpsrv.com, *.jwpcdn.com, jwpltx.com, jwpsrv.a.ssl.fastly.net, *.amazonaws.com and *.cloudfront.net. The relevant ports are 80 and 443.
-
Check the following talk links to see which ones work correctly:
Auto Mode
HTTP Progressive Download Send us your results from the above test links at access@hstalks.com and we will contact you with further advice on troubleshooting your viewing problems. -
No luck yet? More tips for troubleshooting viewing issues
-
Contact HST Support access@hstalks.com
-
Please review our troubleshooting guide for tips and advice on resolving your viewing problems.
-
For additional help, please don't hesitate to contact HST support access@hstalks.com
We hope you have enjoyed this limited-length demo
This is a limited length demo talk; you may
login or
review methods of
obtaining more access.
Printable Handouts
Navigable Slide Index
- Introduction
- The influence of exercise intensity and duration on fuel provision
- Fuel selection for exercise (1)
- Fuel selection for exercise (2)
- Substrate use: Effects of exercise intensity
- Substrate utilization: Effects of exercise duration
- Exercise duration and intensity and fuel use
- Metabolic causes of fatigue during exercise
- Fatigue in high-intensity exercise
- Fatigue in prolonged exercise
- Hypoglycaemia and central fatigue
- Summary
- Key reading
- Thank you!
Topics Covered
- The influence of exercise intensity on fuel provision
- The influence of exercise duration on fuel provision
- Metabolic causes of fatigue during exercise
Talk Citation
Gleeson, M. (2021, September 29). An introduction to exercise metabolism 2 [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved December 3, 2024, from https://doi.org/10.69645/XIEL2006.Export Citation (RIS)
Publication History
Financial Disclosures
- Dr. Gleeson is co-author of textbooks published by Oxford University Press, Human Kinetics, Tourledge, Meyer & Meyer Sport for which he receives royalties. He has received funding for research from several food/drug/supplement companies including Nestle, PepsiCo, GlaxoSmithKline, and Yakult.
An introduction to exercise metabolism 2
Published on September 29, 2021
16 min
A selection of talks on Metabolism & Nutrition
Transcript
Please wait while the transcript is being prepared...
0:00
This is the second part of the talk.
In the first part, we covered some of the basics of energy and energy metabolism,
the different pathways that are available to supply fuel
and to resynthesise ATP during exercise,
and we finished on listing some of the main factors that influence fuel selection for exercise.
In this second talk, I'm going to cover the effects of exercise intensity and
exercise duration on fuel selection for exercise,
and then get into some of the main contributors to the development of fatigue,
or mechanisms of fatigue, that we get during both high-intensity exercise and prolonged exercise.
Then I'll finish with a summary of the main points from both lectures.
0:49
We'll now focus on those two main effects of exercise intensity and
duration on the pattern of fuel supply during prolonged exercise.
1:01
Fuel selection for exercise.
Fat uptake and oxidation by muscle is a relatively slow process,
so it can only supply ATP at a rate that's sufficient to maintain
exercise at an intensity of about 60% of maximal oxygen uptake
(or aerobic capacity), or less than that.
To generate ATP at the high rates we need to sustain higher exercise intensities than that,
there's an increasing reliance on carbohydrate,
and at intensities above about 85% of VO₂ max (aerobic capacity)
the oxidation of carbohydrate is always going to be
the predominant fuel, contributing at least 70% of the energy (or more), with fat contributing 30% (or less).
The higher you get towards your maximal oxygen uptake (aerobic capacity),
the less and less fat contributes, and the more and more comes from carbohydrate,
that's because both the oxidative pathway of carbohydrate utilisation
and the anaerobic pathway of glycolysis can both supply ATP
at a rate that's much faster than fat oxidation can achieve.