When you exercise or take part in a strenuoussport you will notice several changes takingplace in your body:1. Your heart beats stronger and faster2.Your breathing quickens and deepens3.Your body temperature increases4.You start to sweat5.Your muscles begin to ache
1. YOUR HEART BEATS STRONGER AND FASTERDuring exercise it is mainly ADRENALINEthat produces changes in the heartbeat.Adrenaline is a hormone which causes theheart rate to quicken.
2. YOUR BREATHING QUICKENS AND DEEPENSYou breathe quicker so as to get more oxygeninto the lungs. An efficient heart can thentransport this to the working muscles.Training can be of great benefit to theRespiratory System. The capacity of the lungsis increased, which allows more oxygen to betaken in per breath.
Problems produced by exercise vary accordingto the type of sport or event.Problems for the sprinter are different fromthose of the middle distance runner. A shortdistance sprint may cause little problem to atrained sprinter, but a games player, who hasto repeatedly sprint, needs to train to copewith this.
The middle distance runner may not be runningfast enough to get out of breath, but if theyhave to run up a steep hill, as in x.country,they may get somewhat breathless.The same could be said for the 5000m runnerrequired to produce a sprint at the end.The problems of a Marathon runner are quiteunique. Here the emphasis is on stamina. It isnot more oxygen that is needed but storedfood. The problem may not lie in gettingbreathless, but in having enough stored upglucose and fat in reserve to keep going.
3. YOUR TEMPERATURE INCREASESWhen we exercise, our muscles are workingand they generate heat, so our bodytemperature rises.Body temperature is regulated by heatradiating from the skin and water evaporatingby sweating.When we shiver, our muscles are working toproduce heat in order to raise our bodytemperature.
4. YOU START TO SWEATAs we have just seen, some of our energy isturned into heat. The body will tolerate a smallrise in temperature, but very soon we begin tosweat.If the conditions are hot, we sweat more andproduce less urine. We also lose salt as well asbody heat and water.We have to replace the salt so that the bodystays the same, otherwise we will get CRAMP.
It is now common to see drinks being takenduring football, tennis, cycling and many othergames that go on for a long time, in whichcompetitors sweat a lot. This preventsDEHYDRATION.
5. YOUR MUSCLES BEGIN TO ACHEAs we now know, in order to work, musclesneed energy. Energy comes from food, which ismainly converted to GLUCOSE (Sugar)To work more efficiently muscles also needplenty of oxygen.Glucose and oxygen are brought to the musclesin the blood.
Wastes such as carbon dioxide are carriedaway in the blood.This process of getting energy is calledRESPIRATION. Glucose +oxygen = Energy + CO2 + WaterWhen muscles do extra work more Glucose andOxygen are needed, so more blood must flowto the muscles.So the heart beats faster.
Eventually it becomes impossible to get enoughoxygen to the muscles, so they use a differentmethod of getting energy.Glucose is still used, but now there is a wasteproduct called LACTIC ACID.LACTIC ACID is a poison. After a while it willmake the muscle ache, and the muscles willstop working.The athlete has to rest while the blood bringsfresh supplies of oxygen to the muscles.
EXERCISE PHYSIOLOGY-IMMEDIATE EFFECTS OF EXERCISE
EFFECTS OF REGULAR TRAINING AND EXERCISE1. THE HEART PUMPS MORE BLOOD PER BEAT.2.THE RECOVERY RATE BECOMES QUICKER.3.THE RESTING PULSE RATE BECOMES LOWER.4.THE NUMBER OF CAPILLARIES INCREASES.5.THE CARDIOVASCULAR SYSTEM BECOMES MORE EFFICIENT.
EXERCISE PHYSIOLOGY- LONGTERM EFFECTS OF TRAINING
Some idea of fitness can be gained from theresting pulse rate ( RPR ) because withtraining, our heart gets bigger and stronger,and it can supply the same amount of bloodwith fewer beats.However, the RPR does not tell the whole storybecause it is just as important to know howlong the pulse rate takes to get back to normalThis is known as our RECOVERY RATE and thequicker this happens the fitter we are.
LONG TERM BENEFITS OF EXERCISE1. It reduces the risk of coronary heart disease.2.You can work harder for longerExercise improves the Cardiovascular systemand helps to reduce blood pressure.As we saw earlier, it helps to reduce stressand burns off excess calories.
If we are keen to get fit, this will probablymotivate us not to smoke. Smoking is thebiggest cause of CHD. So this is a longer-termeffect of exercise.Over a period of time we can see that theheart of a fit person will beat far fewer times.This makes it much more efficient and causesless stress to be put on the heart. This is alsoa long-term effect of exercise.
With training the heart muscle increases insize, thickness and strength, the chambersincrease in volume and so the whole heart getsbigger.Therefore we can work harder for longer. Thisis yet another long-term effect of exercise.