1. Key Muscle Groups

2. Label Your Body Pectoralis Major Quadriceps Deltoids Hamstrings
Triceps Brachii
Biceps Brachii
Soleus
Trapezius
Rectus Abdominus
Quadriceps
Hamstrings
Gastrocnemius
Hip Adductors
Tibialis Anterior
Latissimus Dorsi
External Obliques

3. Muscles

6. Skeletal Muscle
These muscles are made up of cylindrical fibres and are under the control of the body.
All these muscles are attached to the skeleton.
These muscles make up about 40% of the weight of a man, but less for a woman because women have higher fat percentages.
Muscles are made up of protein, when we are eating protein such as fish or meat we are actually eating the muscle of the animal.

7. Skeletal Muscle
The skeletal muscles are usually long and thin and because they cannot push they are usually paired up with another skeletal muscle.
One muscle contracts causing flexion at the joint, the other contracts extending the joint. These pairs of muscles are called antagonists.
In order to get full movement while one muscle contracts the other must relax (isotonic contraction)

8. Slow Twitch Fast Twitch IIa Fast Twitch IIb
Type 1 Fast Oxidative Glycolytic Fast Glycolytic
Contract slowly
Contract quicker
Contract quickest
Are moderately powerful
Are quite powerful
Are very powerful
Are small
Are bigger
Are the biggest
Have lots of mitochondria
Have fewer mitochondria
Have very few mitochondria
High myoglobin content
Moderate myoglobin content
Low myoglobin content
Resistant to fatigue
Moderately resistent to fatigue
Easily fatigued
High capillary density
Low capillary density
High aerobic capacity / low anaerobic capacity
Relatively high aerobic & anaerobic capacity.
Low aerobic capacity / high anaerobic capacity
Low muscle energy stores e.g. ATP, PC & muscle glycogen.
higher muscle energy stores e.g. ATP, PC & muscle glycogen.
The highest muscle energy stores e.g. ATP, PC & muscle glycogen.

9. Muscle Fibre Types
The different amount of muscle fibre types in the body differ from person to person
It is dependant upon the genes that have been passed through our families
Proportions can vary according to the action of the particular muscle
Muscle involved in maintaining posture are found to have large amounts of slow twitch fibres as they are continuously working to retain good posture.

10. Muscle Fibres and Training
By structuring specific training activities an athlete can develop and bring about changes in skeletal fibres
Suitable training can improve slow twitch fibres to operate more quickly
However it is not possible to convert them to fast twitch fibres

11. Muscle Fibres and how they adapt to exercise.
The right type of exercise will produce the appropriate response. So what is the right type of exercise?
As a result of low intensity, long duration activities…Slow twitch fibres will become better able to produce energy aerobically,
Type IIa fibres will start to take on type I characteristics and
type IIb fibres will begin to become more aerobic efficient
All 3 fibre types will become more efficient as a result of prolonged exposure to a particular environment.
As a result of high intensity, short duration activities….Type IIb fibres will become better able to produce energy anaerobically,
Type IIa fibres will begin to develop type IIb characteristics and
Type I fibres will begin to become more anaerobically efficient
As a result of high intensity, short duration activity that is repeated with little rest… Type IIa fibres will become better able to delay a lactic acid build up,
Type I & type IIb fibres will take on type IIa characteristics.

12. Fibre Recruitment
During exercise the body will use a combination of all 3 Fibre Types depending on exercise intensity
Regardless of activity, always use type 1 first, then select either 2a or 2b depending on activity

13. Force Production Light Intensity Exercise – Mostly type 1
Medium Intensity Exercise –
Type 1 & 2a
High Intensity Exercise –
Type 1, 2a & 2b