The Muscular System

**You need to be able to label each muscle and know what movement it is responsible for.

Immediate effects of exercise Exercise increases the muscles demand for oxygen and glycogen in order to provide energy to meet the demands of the activity. When the body works harder, more waste products are produced, so more blood is pumped around to remove this. When the intensity is low the body can work aerobically for a long time. When the intensity is high and the demand for oxygen is so high, the muscles can not get enough, therefore producing lactic acid. When lactic acid builds up eventually the muscles will not be able to continue. Lactic acid makes the muscles ache, stiffen and cause cramp. Isotonic Contractions – muscle contraction that results in limb movement. (contraction with movement) Isometric Contraction – muscle contract where the muscle tenses but does not lengthen. (Still position)

Effects of regular exercise With training muscles increase in strength and size. Hypertrophy – an increase in muscle mass and size Atrophy – a decrease in muscle mass and size (usually due to injury or stopping training) Muscles are attached to the bones by tendons. Muscles are arranged in Antagonistic pairs, where one muscle contracts (and shortens) and the other relaxes (and lengthens) E.g. Bending of the arm – Bicep contracts, Tricep relaxes. Toned muscles prevent; poor posture, reduce the chances of injuries increases strength increases your working capacity Prevent lower back pain

Potential Injuries and Treatment Soft Tissue Injuries Tears, pulls and strains. Prevent by Warming up – making the muscles warmer and more stretchy, intensity should be gradually increased Cooling down – prevents muscles soreness by removing lactic acid a Treatment: R – Rest I – Ice C – Compression E- Elevation

Lifestyle effects Rest Allows muscles to repair the damaged caused by exercise Allows muscles to re-build and strengthen before the next session Too much training and not enough rest can lead to injuries and fatigue Diet The muscular system needs protein to repair and rebuild preventing atrophy Energy stores need to be replenished after exercise with water and carbohydrates preferably within 2 hours of stopping Performance enhancing drugs Anabolic steriods - increase muscle size and strength -increase the recovery process after training -Help the athlete recover from injury faster