Presentation on theme: "Project 2 The Physiology of Fitness"— Presentation transcript:
1 Project 2 The Physiology of Fitness Topic 1Know the Body’s Response to ACUTE Exercise
2 “Know the Body’s Response to ACUTE Exercise” Musculoskeletal – muscles, bones, ligaments etcCardiovascular – heart, blood vessels, lungs etcRespiratory – lungs, gas exchange etcEnergy Systems – fuel for energy
3 Musculoskeletal Increased Blood Supply to the Muscles More blood in needed within the muscles and so blood from other body parts such asorgans is reduced. This is known as “redistribution”.Increase in Muscle Pliability (bendability)More blood is pumped through the musclesExcess heat is generatedMuscle tissue warms upThe warmer the muscle the more pliable it becomesThe muscle tissue is able to stretch to greater lengths without tearingAs muscle tissue warms up the rate of nervous impulses being sent increasesHeat therefore increases speed of nervous transmission!
4 Musculoskeletal Increased Range of Movement Muscle Fibre Micro Tears Increased production of synovial fluidThis is because exercise means our joints are moving quickly, so there needs to be more synovial fluid in the joints to allow this movementThe joints become warmerThe synovial fluid becomes thinner, making movement more efficient.Increased movement and mobility of the joints:As the joints get warmer there is an increased elasticity of tendons and ligamentsMuscle Fibre Micro TearsDuring exercise, tiny tears called micro tears develop within the muscle fibres. Muscles when put under excessive stress such as lifting weights can cause small tears in the muscles called micro fibre tears. During rest from training/exercise muscle then repairs the tear. Muscle reacts to these micro tears by adding more proteins to the muscle, resulting in muscle growth. Micro tears are tiny and cause mild to moderate soreness and stiffness.
5 Cardiovascular Heart Rate Anticipatory Response Before exercise even begins heart rate increases in anticipation. This is known as the anticipatory response. It is mediated through the releases of a neurotransmitters called epinephrine and norepinephrine also known as adrenaline and noradrenaline (from the adrenal glands)Heart Rate Activity Responseas we start to exercise our HR increases this is directly proportional to the increase in intensity until you are near exhaustion. As you approach this point your HR levels off, this is your HR max.
6 Cardiovascular Increased Blood Pressure At rest, a typical systolic blood pressure in a healthy individual ranges from mmHg and 60-90mmHg for diastolic blood pressure.During exercise systolic pressure, the pressure during contraction of the heart (known as systole) can increase to over 200mmHg and levels as high as 250mmHg have been reported in highly trained, healthy athletes (2).Diastolic pressure on the other hand remains relatively unchanged regardless of exercise intensity. In fact an increase of more than 15 mm Hg as exercise intensity increases can indicate coronary heart disease and is used as marker for accessing an exercise tolerance test.Vasoconstriction & VasodilationWhen you exercise your face goes red!!! During exercise body temperature rises. In order to disperse the heat, blood vessels expand (vasodilate) and move towards the surface. Blood being directed away form certain areas (e.g. organs so that blood can redirect to the muscles) vasoconstrict (get smaller).
7 Respiratory Function During Exercise Recap on Function of Respiratory System:To provide a continuous and adequatesupply of Oxygen to the tissuesTo enable the removal ofCarbon Dioxide from the bodyTo assist in the maintenance ofthe acid-base (pH) of the bodyTo assist in the control ofbody temperature
8 Respiratory Increase In Breathing Rate The number of breaths per minute increases, due to neural & chemical influencesNeural ControlThe rate & depth of breathing is controlled by the respiratory centre located in the Medulla (brain stem) which send neural impulses to the respiratory muscles.Chemical ControlChemoreceptors are located around the body (mainly the bigger blood vessels such as the aorta). These are sensitive to chemicals such as O2, CO2 & pH (acid) levels within the blood. If they detect a change in normal levels, they stimulate the body to remove them by increased breathing.(pH changes due to lactic acid (release of hydrogen ions))Increased Tidal VolumeVolume taken in with each breath increases in an attempt to take in more O2 and dispose of more CO2
9 Energy Systems phosphocreatine lactic acid aerobic energy continuum energy requirements of different sport and exercise activities
10 Duration vs. IntensityAll three energy systems contribute at the start of exercise but the contribution depends upon the individual, the effort applied or on the rate at which energy is used.The following graph shows how the energy systems contribute to the manufacture of ATP over time when exercising at 100% effort.The thresholds (T) indicate the point at which the energy system is exhausted - training will improve the thresholds times.
11 Recap of the Energy Systems. The body uses different energy systems for each activityQuick movements-lasts a few secondsReduced speed-lasts for several minutesReduced intensity(50%)-lasts for several hoursPredominant Energy PathwaysATP (2-3 seconds)ATP-CP Energy System (8-10 seconds)Anaerobic Energy System (2-3 minutes)Aerobic Energy System (3 minutes +)ATP is stored in small amounts, therefore the rest is stored as:Eaten as… Broken down into… Stored as…Carbohydrates = Glucose = Glycogen (muscle & liver)Fats = Fatty Acids = Body fatProtein = Amino Acids = Growth, repair or excreted as waste
12 Fuel for Exercise:Anaerobic Energy System = Carbohydrates are the only fuel sourceWith prolonged exercise, Carbohydrates are the first fuel choice, as exercise continues, FAT becomes predominant :As exercise intensity , energy supplied by Carbohydrates As duration , energy supplied by fat Protein is not a main fuel source except in an emergency :As glycogen , energy supplied by protein Each system plays an important role in energy production:All energy systems are “on” at all timesThis gives us a variety of movementsThe systems interact to supply Energy for the activitySo, there is always a trade-off between exercise intensity and duration:High intensity (fast, hard) requires a lot ofglycogen so duration has to be shortLow-intensity (slow, easy) requires littleglycogen so duration can be long
13 Different Sports using Different Energy Systems ATP-CP and LA %LA-Aerobic%AerobicBasketball6020Fencing9010Field eventsGolf swing955Gymnastics8015Hockey5030Distance running70RowingSkiing33SoccerSprintsSwimming 1.5kmTennisVolleyballTable adapted from Fox E. L. et al, The Physiological Basis for Exercise and Sport, 1993