1.2.4 – Active lifestyles and your muscular system Learning objectives To understand and describe the term ‘antagonist pair’ To understand the different types of muscle contraction. To understand how to improve muscular strength and muscular endurance. To be able to explain the long term benefits of exercise on muscles.

Muscle action Muscles are arranged in antagonistic pairs. The fixed or non-moving end is known as the origin. The insertion is known as the moving end. Muscles are arranged in antagonistic pairs. As one muscle contracts (shortens) its partner relaxes (lengthens).

Muscle action Can you think of another antagonists pair in the body?

Types of muscular contractions. Isotonic contractions – ‘Muscle contractions that produce MOVEMENT’. The contracting muscle shortens. Isotonic contractions are generally the more important type of contraction for sportspeople, especially games players. They produce both speed and power.

Isometric contractions – ‘Muscle contractions that DO NOT create movement’ – the muscle neither shortens nor lengthens. Isometric contractions produce static strength. To hold the body in a particular position (e.g., scrum). Can you name others?

Phases of a press up: When is it isotonic/isometric?

Exam Questions

Exercise and muscles The immediate effects of exercise on the muscles: Working muscles produce heat Build up of lactic acid Blood is re-distributed to working muscles Glycogen store in muscles are released Cardiac muscle works harder Aching muscles

Strength training The strength of muscles can be increased through training. Strength training makes muscles grow thicker with a better contractual force. (increased muscle size is called hypertrophy) Strength training involves repeatedly lifting, pushing or pulling against a large resistance. Image © 2006 Jupiterimages Corporation HEAVY WEIGHT + LOW REPS

What athlete would benefit/use strength training? Shot putt Sprinters Weightlifter Strength training is also used by performers rehabilitating from injury.

Endurance training Muscular endurance means the ability of muscles to repeatedly contract without getting tired. Muscles become better at using oxygen and work better over long periods of time. LIGHT WEIGHT + HIGH REPS

What athlete would use endurance training? 1500M Runner Rowers 800m Swimmer Muscular endurance is important in events like long distance running, cycling and rowing.

Muscles and injury When exercising there is always a risk of muscle injury. A STRAIN is a soft tissue injury (pulled or overstretched muscle). Treatment: R.I.C.E. (Rest, Ice, Compression, Elevation) Avoidance: Warm up thoroughly.

Muscles and injury A SPRAIN is a soft tissue injury (Twisted or wrenched ligament). Sprains occur when ligaments at joints get stretched and torn. i.e. Sprained ankles are very common Severe sprains result in torn ligaments. Treatment: R.I.C.E. (Rest, Ice, Compression, Elevation) Avoidance: Strengthen area using weight training

Treatment for soft tissue injuries Rest the injured part. I Apply Ice to reduce the swelling for 10 minutes (max). Frozen peas work well! C Compress the injury, possibly using a tubigrip bandage. E Elevate the part to decrease the blood supply.

Tennis Elbow Tennis elbow is an inflammation, soreness, or pain on the outside side of the upper arm near the elbow. Causes: This injury is caused by repetitively twisting the wrist or forearm. The injury is classically associated with tennis playing, hence the name "tennis elbow," but any activity that involves repetitive twisting of the wrist (like using a screwdriver) can also lead to it.

Tennis elbow treatment: - R.I.C.E. - Steroid injection Strapping can help prevent the occurrence of tennis elbow

Golfer’s Elbow Golfer’s elbow is similar to tennis elbow. The repetitive strain is on the inside of the elbow. Treatment: RICE