440 likes | 1.25k Views
Slow Twitch and Fast Twitch Muscle Fibres. Did you eat white meat or dark meat over the holidays?. Slow-Twitch. Most active during: long-distance running, swimming, and cycling Red or dark in colour
E N D
Slow Twitch and Fast Twitch Muscle Fibres Did you eat white meat or dark meat over the holidays?
Slow-Twitch Most active during: long-distance running, swimming, and cycling Red or dark in colour Generate and relax tension slowly; able to maintain a lower level of tension for long durations Low levels of myosin ATPase and glycolytic enzymes High levels of oxidative enzymes
Fast-Twitch • Ideal for: short sprints, power lifting, and explosive jumping • Pale in colour • Ability to tense and relax quickly; generate large amounts of tension with low endurance levels • High levels of myosin ATPase and glycolytic enzymes
Approximate Distribution of Muscle Fibre Types for Different Sports
The Importance of Myoglobin • The difference in _____________________ is determined by the amount of ____________ used in energy production • Myoglobin: ____________________________
Myoglobin • Slow fibres vs. Fast fibres • Slow twitch fibres are __________ in myoglobin • Fast Twitch Fibres have ______________ amounts of myoglobin
3 Fibre Types • Type I or Slow-Oxidative (SO) • Type IIA or Fast-Oxidative Glycolytic (FOG) • Type IIB of Fast-Glycolytic (FG)
Why the Split of Type II Fibres? • Studies have shown that there is evidence for changing the type ________to Type ______ muscle fibres with endurance training • THERE IS NO WAY ANY TYPE ___ MUSCLE FIBRES CAN BECOME TYPE ____ • In other words a fast twitch muscle can _________become a slow twitch muscle
So how are the fibres distributed? • How a muscle works is determined by its fibre type and vice versa • TWO categories for basic muscle functions: • Tonic • Phasic
Tonic Muscles • These are used on a daily basis for • High concentration of _________ twitch fibres (Type I) • Great for endurance activities • Core and back muscles: constantly contracted
Phasic Muscle • Higher percentage of ________ twitch fibres • Example: Biceps have a lower amount of Type I fibres and a higher amount of type II because they are used for explosive movement (lifts)
So how do you find where these fibres are? • The only true way is to do a _____________to find the percentage of each type of fibre. • Muscle biopsy: tissue sample using a needle to take a small amount from the muscle belly
Athletic Performance • Elite athletes may have __________% of a specific fibre type in their body
Why does Kenya keep winning in long distance? • You are going to read a short article on page 91 • Answer the following questions • What has been found regarding the Kenyan’s muscle fibre type? • What social factors have played a large role in Kenyan runners?