The Effect of Exercise on the Body

1. The Effect of Exercise on the Body Miss Lisa Mc Sweeney

2. Lesson Objectives By the end of this lesson student should be able to: • Know the effects of exercise on the Skeletal System • Know the effects of exercise on the Muscular System • Know the effects of exercise on the Cardiovascular System • Know the effects of exercise on the Respiratory System • Know the effects of exercise on the Neuromuscular System

3. Coursework- Task 1 In a report format For two different athletes describe the adaptations of the body’s systems to long-term (chronic) exercise and their sport. You can choose from the following athletes: • Marathon runner • High jumper • 200m sprinter • Triple jumper • Javelin In your answer you need to include: • An exercise period of at least 8 weeks • The cardiovascular and respiratory systems • The neuromuscular and skeletal systems • The energy systems • Aerobic exercise and the effects • Anaerobic exercise and the effects (P6, P7)

4. Skeletal System • The condition of a bone may be improved by exercise as it responds to mechanical stresses. • These mechanical stresses usually take the form of skeletal muscle pulling at their points of attachment being their origins and insertions. • Where these mechanical stresses are applied, most it has been shown that more mineral salts are deposited and more collagenous fibres are produced. • Therefore, both the density and size of bone in these areas may be increased and these changes in bone structure are stimulated by increased loads being placed on the skeleton. • This has been borne out by greater bone mass being observed in weight lifters than in other lighter endurance athletes such as joggers. • Other examples include racquet players who have been shown to have greater bone density in their playing arms.

5. Cont... • It has even been shown that if a leg is immobilised by being placed in plaster, due to a fracture, that even after a few weeks the bone becomes decalcified from lack of mechanical stress. • Whilst it may therefore be considered beneficial to utilise exercise to maintain healthy bones, great care must be taken with children whose bones and muscles are still developing. • They should not be subjected to forms of sport involving high degrees of mechanical stress, partly because of the weaknesses that still exist within the bones, and also because of adverse effects on the development of these bones before maturity (e.g. Gymnasts). • There are two main effects on bones as we grow older. Bones begin to lose calcium and this is one of the factors contributing to the condition called osteoporosis. • Secondly, with age less protein is produced which alters the make-up of bone and sometimes creates brittle bones.

7. The effect on different sports • Long Distance Runner ....................................................................................................................................................................................................................................................................................................................................................................................................................... • High Jumper .......................................................................................................................................................................................................................................................................................................................................................................................................................

8. Muscular System Although exercise also provides benefits to the cardiovascular and skeletal systems, the primary benefit of regular training is felt by the muscular system. Muscle Development Process • Training the body causes micro-tramua in the muscles (tiny "injuries" that must be repaired). • If the intensity of the exercise is sufficient to convince the body that additional muscle is necessary for survival, the body compensates by repairing old muscle tissue and creating new tissue. Muscle Recruitment • One of the primary benefits from exercise is the ability to increase muscle recruitment. • Neglect of muscle use results in atrophy to the muscle and the underlying nerve pathways activating that muscle. • You might have noticed that the longer you train with weights, the more you can "feel" the muscle working. This is an example of the increased "mind-muscle" connection that becomes possible through regular training.

9. Cont.... Muscle Strength • One of the benefits everyone knows is the concept of training as a way to increase maximal strength levels. • The more you use a muscle (and the more efficient you become at recruiting it), the more your potential for force generation rises. • Muscle size is not linearly coordinated with muscle strength; you've probably seen relatively small people at the gym lifting large amounts of weight. These people are more efficient at generating maximal strength with the muscle tissue they have. Muscle Size • Continue to lift heavier weights to gain muscle and get bigger. • Another effect of exercise on the muscular system is an increase in muscular size. So long as you continue to progress in the gym by lifting more weights, the body will continue to adapt--adding additional size (and strength) to meet the imposed demands. Your body's primary goal is survival, and by training with heavier and heavier weights, you are telling it that it must grow if it hopes to "survive" the workouts to come.

10. Cont... Muscle Endurance • On top of increased efficiency at recruiting the various muscle fibers (the mind-muscle connection), with consistent training your body will also increase its endurance. • This is because the muscle becomes more capable of disposing of accumulated waste (such as lactic acid build-up) even while in the midst of a set. • So while during your first week of training you might be able to perform only five reps before "the burn" becomes too intense to continue, you might be able to perform 10 or more reps the following week. • This is not necessarily because your muscle became "stronger." It could be because your muscle became more efficient at disposing of waste products through the bloodstream.