THE EFFECTS OF EXERCISE ON THE BODY EXERCISE PHYSIOLOGY THE EFFECTS OF EXERCISE ON THE BODY

WHEN YOU EXERCISE OR TAKE PART IN A STRENUOUS SPORT YOU WILL NOTICE SEVERAL CHANGES TAKING PLACE IN YOUR BODY: YOUR HEART BEATS STRONGER AND FASTER YOUR BREATHING QUICKENS AND DEEPENS YOUR BODY TEMPERATURE INCREASES YOU START TO SWEAT YOUR MUSCLES BEGIN TO ACHE

1. YOUR HEART BEATS STRONGER AND FASTER DURING EXERCISE IT IS MAINLY ADRENALINE THAT PRODUCES CHANGES IN THE HEARTBEAT. ADRENALINE IS A HORMONE WHICH CAUSES THE HEART RATE TO QUICKEN.

2. YOUR BREATHING QUICKENS AND DEEPENS YOU BREATHE QUICKER SO AS TO GET MORE OXYGEN INTO THE LUNGS. AN EFFICIENT HEART CAN THEN TRANSPORT THIS TO THE WORKING MUSCLES. TRAINING CAN BE OF GREAT BENEFIT TO THE RESPIRATORY SYSTEM. THE CAPACITY OF THE LUNGS IS INCREASED, WHICH ALLOWS MORE OXYGEN TO BE TAKEN IN PER BREATH.

3. YOUR TEMPERATURE INCREASES WHEN WE EXERCISE, OUR MUSCLES ARE WORKING AND THEY GENERATE HEAT, SO OUR BODY TEMPERATURE RISES. BODY TEMPERATURE IS REGULATED BY HEAT RADIATING FROM THE SKIN AND WATER EVAPORATING BY SWEATING. WHEN WE SHIVER, OUR MUSCLES ARE WORKING TO PRODUCE HEAT IN ORDER TO RAISE OUR BODY TEMPERATURE.

4. YOU START TO SWEAT AS WE HAVE JUST SEEN, SOME OF OUR ENERGY IS TURNED INTO HEAT. THE BODY WILL TOLERATE A SMALL RISE IN TEMPERATURE, BUT VERY SOON WE BEGIN TO SWEAT. IF THE CONDITIONS ARE HOT, WE SWEAT MORE AND PRODUCE LESS URINE. WE ALSO LOSE SALT AS WELL AS BODY HEAT AND WATER. WE HAVE TO REPLACE THE SALT SO THAT THE BODY STAYS THE SAME, OTHERWISE WE WILL GET CRAMP.

5. YOUR MUSCLES BEGIN TO ACHE AS WE NOW KNOW, IN ORDER TO WORK, MUSCLES NEED ENERGY. ENERGY COMES FROM FOOD, WHICH IS MAINLY CONVERTED TO GLUCOSE (SUGAR) TO WORK MORE EFFICIENTLY MUSCLES ALSO NEED PLENTY OF OXYGEN. GLUCOSE AND OXYGEN ARE BROUGHT TO THE MUSCLES IN THE BLOOD.

WASTES SUCH AS CARBON DIOXIDE ARE CARRIED AWAY IN THE BLOOD. THIS PROCESS OF GETTING ENERGY IS CALLED RESPIRATION. GLUCOSE +OXYGEN = ENERGY + CO2 + WATER WHEN MUSCLES DO EXTRA WORK MORE GLUCOSE AND OXYGEN ARE NEEDED, SO MORE BLOOD MUST FLOW TO THE MUSCLES. SO THE HEART BEATS FASTER.

EVENTUALLY IT BECOMES IMPOSSIBLE TO GET ENOUGH OXYGEN TO THE MUSCLES, SO THEY USE A DIFFERENT METHOD OF GETTING ENERGY. GLUCOSE IS STILL USED, BUT NOW THERE IS A WASTE PRODUCT CALLED LACTIC ACID. LACTIC ACID IS A POISON. AFTER A WHILE IT WILL MAKE THE MUSCLE ACHE, AND THE MUSCLES WILL STOP WORKING. THE ATHLETE HAS TO REST WHILE THE BLOOD BRINGS FRESH SUPPLIES OF OXYGEN TO THE MUSCLES.

CHANGES AS A RESULT OF EXERCISE/TRAINING BODY SYSTEM SHORT TERM RESPONSE TO EXERCISE LONG TERM RESPONSE TO EXERCISE MUSCULAR MUSCLES RECEIVE MORE BLOOD AND OXYGEN MUSCLES INCREASE IN TEMPERATURE MUSCLES GET MORE FLEXIBLE MUSCLES GET LARGER AND STRONGER MUSCLES GET MORE BLOOD VESSELS CAN RECEIVE MORE OXYGEN MUSCLES CAN STORE MORE ENERGY(GLYCOGEN) CARDIO-VASCULAR THE BLOOD IS ABLE TO CARRY MORE OXYGEN HEART BEAT INCREASES MORE BLOOD PUMPED AROUND BODY BLOOD PRESSURE INCREASES THE HEART GETS LARGER RESTING HEART RATE GETS LOWER HEART RATE RETURNS TO NORMAL FASTER EXERCISE HEART GETS LOWER RESPIRATORY BREATHING RATE INCREASES AMOUNT OF AIR TAKEN IN EACH BREATH INCREASES THE LUNGS CAN BREATHE IN AND OUT A GREATER VOLUME OF AIR, AND WITH IT OXYGEN

EFFECTS OF REGULAR TRAINING AND EXERCISE THE HEART PUMPS MORE BLOOD PER BEAT. THE RECOVERY RATE BECOMES QUICKER. THE RESTING PULSE RATE BECOMES LOWER. THE NUMBER OF CAPILLARIES INCREASES. THE CARDIOVASCULAR SYSTEM BECOMES MORE EFFICIENT.

SOME IDEA OF FITNESS CAN BE GAINED FROM THE RESTING PULSE RATE ( RPR ) BECAUSE WITH TRAINING, OUR HEART GETS BIGGER AND STRONGER, AND IT CAN SUPPLY THE SAME AMOUNT OF BLOOD WITH FEWER BEATS. HOWEVER, THE RPR DOES NOT TELL THE WHOLE STORY BECAUSE IT IS JUST AS IMPORTANT TO KNOW HOW LONG THE PULSE RATE TAKES TO GET BACK TO NORMAL THIS IS KNOWN AS OUR RECOVERY RATE AND THE QUICKER THIS HAPPENS THE FITTER WE ARE.

LONG TERM BENEFITS OF EXERCISE IT REDUCES THE RISK OF CORONARY HEART DISEASE. YOU CAN WORK HARDER FOR LONGER EXERCISE IMPROVES THE CARDIOVASCULAR SYSTEM AND HELPS TO REDUCE BLOOD PRESSURE. AS WE SAW EARLIER, IT HELPS TO REDUCE STRESS AND BURNS OFF EXCESS CALORIES.

ENERGY SYSTEMS THREE PATHWAYS PROVIDE ENERGY FOR PHYSICAL ACTIVITY. TWO ARE ANAEROBIC(WITHOUT OXYGEN) AND THE OTHER AEROBIC(WITH OXYGEN) THE TYPE OF ENERGY PATHWAY USED IS DEPENDENT ON THE TYPE OF ACTIVITY PERFORMED ACTIVITY THAT IS LONGER IN DURATION AND OF LOW INTENSITY IS FUELLED BY THE AEROBIC ENERGY SYSTEM ACTIVITY THAT IS SHORTER IN DURATION AND OF HIGHER INTENSITY IS FUELLED BY THE ANAEROBIC ENERGY SYSTEMS

AEROBIC SYSTEM ENERGY IS SUPPLIED TO THE BODY THROUGH THE CONSUMPTION OF OXYGEN. THIS COMBINES WITH LACTIC ACID TO PRODUCE WATER, THEREFORE THERE IS NO EFFECT ON PERFORMANCE. ACTIVITIES THAT USE THIS ENERGY SYSTEM INCLUDE RUNNING, SWIMMING AND CYCLING LONG DISTANCES THINK……WHEN WE PERFORM THE CROSS COUNTRY COURSE…..IT STARTS RELATIVELY EASY, GETTING THE BODY READY FOR MORE STRENUOUS EXERCISE-LOW INTENSITY AND MAINLY USES THE AEROBIC SYSTEM. THE BODY WILL USE SOME OF ITS ATP STORES (ATP IS ADENOSINE TRI-PHOSPHATE….., A CHEMICAL PRODUCED IN THE BODY THAT HELPS DELIVER OXYGEN)…AS IT IS IMMEDIATE(ALTHOUGH SHORT LASTING)TO GET US THROUGH THE VERY INITIAL START TO THE RUN. THE BODY TAKES A SHORT WHILE FOR THE AEROBIC SYSTEM TO START WORKING EFFECTIVELY(SOMETIMES CALLED OUR SECOND WIND), AND UNTIL IT IS WORKING EFFICIENTLY, THE BODY RELIES INITIALLY ON ANAEROBIC STORES OF ATP. THINK STADIUM LIGHTING…..PAGE 63

ANAEROBIC LACTIC SYSTEM THE ANAEROBIC LACTIC SYSTEM IS USED FOR SHORTER DURATION, HIGH INTENSITY ACTIVITY TYPICALLY LASTING BETWEEN 30-90 SECONDS. ENERGY IS SUPPLIED THROUGH THE CONSUMPTION OF CARBOHYDRATE. THIS CAUSES THE BUILD UP OF LACTIC ACID, WHICH EVENTUALLY CAUSES PERFORMANCE TO DECREASE. AT THIS POINT THE PERSON EITHER LOWERS THEIR INTENSITY AND ALLOWS THE AEROBIC SYSTEM TO CONTINUE FUELLING THE EXERCISE, OR THEY STOP EXERCISING COMPLETELY. ACTIVITIES THAT USE THIS ENERGY SYSTEM INCLUDE TEAM SPORTS SUCH AS RUGBY, NETBALL AND SOCCER, WHERE HIGH INTENSITY ACTIVITY IS PERFORMED FOR SHORT PERIODS OF TIME.

ANAEROBIC CP SYSTEM THE ANAEROBIC CP SYSTEM IS USED FOR VERY SHORT DURATION, HIGH INTENSITY ACTIVITY THAT TYPICALLY LASTING UP TO 30 SECS. ENERGY IS SUPPLIED TO THE BODY THROUGH THE CONSUMPTION OF CREATINE PHOSPHATE. THERE ARE NO BY PRODUCTS WITH THIS ENERGY SYSTEM AND IT KEEPS GOING UNTIL ALL THE STORED ENERGY IS USED UP, AT WHICH POINT PERFORMANCE SUFFERS. ACTIVITIES THAT USE THIS SYSTEM INCLUDE JUMPING MOVEMENTS SUCH AS LONG AND TRIPLE JUM, THROWING ACTIVITIES SUCH AS FIELDING A CRICKET BALL AND EXPLOSIVE SPRINTING SUCH AS THE 60 OR 100M

Exercise and the Body

ENERGY SYSTEMS Energy for muscular activity and other biological work comes from the breakdown of adenosine triphosphate (ATP). ATP loses one phosphate molecule and breaks down to Adenosine diphosphate. Since the store for ATP is limited, the body must regenerate its ATP as quickly as it is broken down. This regeneration connects the ADP and Pi together again to create ATP once more. This regenerating of ATP is done by the breakdown of fuel reserves. There are three energy systems for this ATP-PC system Lactic acid system Oxygen (or aerobic ) system

The ATP-CP System The ATP- PC system uses a chemical fuel reserve, Creatine Phosphate, which is stored in the muscle. This process is anaerobic meaning it does not require the use of oxygen for it to work. CP is broken down into Creatine and Phosphate and the energy released from the breakdown is used to combine ADP and Pi to produce ATP. The supply of CP is limited and can only be used effectively for 10 to 20 seconds. When sufficient oxygen is available CP is regenerated ready to use again if needed.

The Lactic Acid System The lactic acid system uses the anaerobic breakdown of glycogen . Carbohydrate is stored in the body as glycogen (in the liver and in muscles). This process does not require oxygen. From the break down of glycogen we get a bi-product called pyruvic acid. At this stage the pyruvic can follow two courses of action. In the first if insufficient oxygen is available for further breakdown the pyruvic acid becomes lactic acid and is stored until sufficient oxygen is present and it then becomes pyruvic acid again and begins its aerobic breakdown.

The Aerobic System The Aerobic system produces its energy by utilising oxygen. It is performed through a series of chemical reactions known as the Krebs Cycle. Here we have the continued breakdown of glycogen from when it becomes pyruvic acid and enters the mitochondria. Fats (and in extreme circumstances proteins) are also broken down here as they can only be broken down aerobically. The results are the regeneration of ATP molecules and the production of by-products - water and carbon dioxide.

Summary of Energy Systems ATP-CP System Lactic Acid System Aerobic System Anaerobic Anaerobic Aerobic Very rapid Rapid Slow Chemical: CP Food: glycogen Food: CHO, Fat, Protein Very limited ATP Limited ATP Unlimited ATP Muscular stores Lactic Acid causes No fatiguing limited fatigue by-products Explosive, sprint 1 to 3 min duration Endurance 100m 400m Marathon

WHAT HAPPENS TO OUR BODY IN EXERCISE? Breathing rate gets deeper and faster: This is because the working muscle need more oxygen to function. By breathing faster and deeper more oxygen is getting into the lungs. From here oxygen then enters the blood and is then pumped by the heart around the body to the working muscles. Heart Rate Increases: The heart pumps blood and oxygen in the blood around the body. When the body and the muscles in particular need more oxygen the heart pumps faster to get more oxygen to the muscles.

THINGS TO THINK ABOUT: There are many physiological changes in the body at exercise What makes it difficult to sprint as fast as you can for more than one minute? Write a detailed answer in paragraph form.