Uploaded December 2024 | Updated September 2026, 14 hours ago

---

In this video, we look at slow-twitch and fast-twitch muscle fibres. First we explore what is meant by antagonistic muscle pairs. We then explore slow-twitch and fast-twitch muscle fibres and how they are adapted for different functions.

Image credits:

Tendons
commons.wikimedia.org/wiki/File:Magnified_view_of_a_Tendon.jpg
upload.wikimedia.org/wikipedia/commons/e/ea/Magnified_view_of_a_Tendon.jpg

Biceps triceps animation
commons.wikimedia.org/wiki/File:Animation_triceps_biceps.gif
Niwadare, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Marathon runner
commons.wikimedia.org/wiki/File:Lydd_Half_Marathon_%26_20_Miler_2016_FNK_9168_(25509480890).jpg
Funk Dooby from Kent, UK, CC BY-SA 2.0 creativecommons.org/licenses/by-sa/2.0, via Wikimedia Commons

Calf muscle animation
commons.wikimedia.org/wiki/File:Triceps_surae_-_animation.gif
Polygon data were generated by Database Center for Life Science (DBCLS)[2], CC BY-SA 2.1 JP creativecommons.org/licenses/by-sa/2.1/jp/deed.en, via Wikimedia Commons

Biceps animation
commons.wikimedia.org/wiki/File:Biceps_brachii_muscle_-_animation03.gif
Anatomography, CC BY-SA 2.1 JP creativecommons.org/licenses/by-sa/2.1/jp/deed.en, via Wikimedia Commons

Man with personal trainer
commons.wikimedia.org/wiki/File:Personal_fitness_training_bundall.jpg
Getmotivatedfitnes, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

Woman exercising biceps
commons.wikimedia.org/wiki/File:PreacherBenchBicepsCurl.JPG
No machine-readable author provided. GeorgeStepanek assumed (based on copyright claims)., CC BY-SA 3.0 creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons