Pdhpe 4U - Chronic Adaptations PDF

Preview

Summary

Pdhpe 4U - Chronic Adaptations...

Description

PE Unit 4

Chronic Adaptations Aerobic Training… - Cardiovascular

• Heart - Increase in Left Ventricle Size As a result of aerobic training, the left ventricle size increases at rest, sub-max and max. This results in a greater volume of blood being ejected from the left ventricle each beat and delivered to working muscles, therefore increasing the amount of oxygen delivered to muscles. More oxygen being used means more reliance on the aerobic system, therefore enable athlete to perform at a higher intensity before lactate removal is exceeded by production

- Increase in Stroke Volume As a result of aerobic training, stroke volume increases at rest, sub-max and max. This allows for a greater amount of oxygen to be pumped around the heart per beat, and ultimately to the working muscles, therefore increasing the amount of oxygen delivered to the working muscles, thus improving performances.

- Increase in Cardiac Output Cardiac output is the amount of blood ejected from the left ventricle of the heart per minute. Increase in cardiac output is designed to bring about an increase in oxygen delivery to the working muscles and heart. Cardiac output remains the same at rest and sub-max because, A chronic adaptation to endurance training is a decrease in resting heart rate (HR), so cardiac output (Q) = stroke volume (SV) × HR, therefore an increase in stroke volume and a decrease in heart rate gives no overall change to cardiac output.

- Decrease in Steady State and Recovery Heart Rate As a result of aerobic training, heart rate decreases at rest and sub-max, due to an increase in stroke volume which allows a greater amount of blood to be pumped around the heart per beat. As a result, the heart does not have to beat as often to produce the same cardiac output and therefore does not use as much energy.

• Blood Vessels - Increase in Capillary Density to Heart Muscles As a result of aerobic training, there is an increased capillarisation of heart muscle. Capillary density and blood flow to the heart increase as a result of cardiac hypertrophy (enlargement of the heart muscle). The increased supply of oxygen and blood flow to the heart allows to become more stronger and efficient

- Increase in Blood Flow from Organs to Working Muscles As you exercise your body needs large amounts of oxygen, glucose, amino acids, and a molecule called ATP to allow the muscles to contract and do work as well as 10

PE Unit 4 remove by-products. Flow flow increases as capillaries dilate allowing blood to travel faster in order to meet the demands of the body.

- Increase in Capillary Density at Muscles Uses less oxygen and is more efficient and it lessens oxygen cost and oxygen can by used to support muscular contractions otherwise.

- Increase in High Density Lipoproteins (HDL) Helps to remove plague from arteries and aids in lowering cholesterol levels, therefore decreasing the amount of resistance in blood vessels. HDL cholesterol absorbs cholesterol and carries it back to the liver, which flushes it from the body.

- Decrease in Low Density Lipoproteins (LDL) Makes up the majority of the body’s cholesterol. Known as “bad” cholesterol due to it’s high levels, it can lead to plaque buildup in your arteries and result in heart disease or stroke.

• Blood - Increase in Blood Volume Higher volume means more transportation of oxygen and removal of by-products from working muscles. Can help delay onset of fatigue.

- Increase in Plasma Levels Slows the onset of dehydration and increase in body temperature causing fatigue as the body’s able to release more heat (plasma-sweat)

- Increase in Red Blood Cell Count (RBC) + Haemoglobin By increasing, haemoglobin levels do also, thus increasing oxygen carrying capacity. This means that more oxygen can be carried in the blood, and delivered to working muscles. !

- Increase in Myoglobin Increases the oxygen transfer between cell membranes and mitochondria meaning aerobic ATP can be produced at a faster rate, supplying athlete with more energy.

- Increase in Lactate Threshold Aerobic training gives your body the ability to be trained to increase the threshold where lactate production exceeds removal. By doing so, the athlete can perform at a higher intensity for a longer duration before fatigue due to lactic acid production occurs.

- Decrease in Blood Pressure Cardio protective effect. Oxygen and blood can be transported around the body more effectively, therefore to working muscles.

11

PE Unit 4 - Respiratory

- Increase in Lung/Vital Capacity Allows for more oxygen to to be taken into the body and transported to muscles, also increasing VO2 Max.

- Increase in Aerobic Capacity Improves restoration of PC and allows for the aerobic system to be used over a larger period.

- Increase in Tidal Volume By having a larger amount of volume per breath, it increases the amount of oxygen taken up and transported to the muscles.

- Increase in Alveolar-Capillary Surface Area It makes for a larger diffusion site, therefore allowing greater amount of gases (oxygen) to be exchanged at the lungs.

- Increase in Pulmonary Diffusion As a result of aerobic training, a greater amount of oxygen is able to be extracted and transferred to the blood via the alveolar-capillary interface. Because of increases in both the number of capillaries surrounding the alveoli, and lung volume, there is a quicker transfer of oxygen to and removal of CO2 from the blood. This means that oxygenated blood can be delivered to the muscles quicker

- Increase in Ventilation (Max Intensity) - Decrease in Ventilation (Rest and Sub-max) As a result of aerobic training, Respiratory Rate (RR) decreases at rest and submax. This is due to an increase in tidal volume which means more air is breathed in and out per breath and therefore less breaths are needed. The decrease in RR means the air stays in the lungs longer between breaths, therefore there is more time for oxygen extraction

- Decrease in Oxygen Cost More oxygen is available to be sent to working muscles. -the rate of oxygen usage for a particular task or work rate.

12

PE Unit 4 - Muscular

- Increase in a-Vo2 Difference More oxygen can be extracted by working muscles, improving performance.

- Increase in Capillary Supply/Density Surrounding capillaries will enhance the supply and removal of by-products. Creates larger surface area for oxygen to diffuse, therefore more goes to working muscles.

- Increase in Myoglobin Increases a-Vo2 difference by extracting more oxygen from the blood. Also increases the amount of oxygen going to mitochondria increasing aerobic ATP production.

- Increase in Mitochondria (size, number, surface area) Allows for greater aerobic ATP release and oxidative enzymes (combine chemically with oxygen) will help this, therefore improves performance. More sites, and more storage.

- Increase in Oxidative Enzymes They increase the rate at which ATP is produced aerobically.

- Increase in Glycogen and Triglyceride Stores These enable muscles to continue working for longer, particularly glycogen which requires minimal oxygen and energy to break down, by being readily available in muscles, and my having more, athlete is less likely to use fats, decreasing performance.

- Increase in Fibre Size Allows to store more ATP in the muscle and can improve performance.

- Increase in Glycogen Sparring Allows athlete to work at higher intestines later on in the performance.

- Increase in Glycogen Synthesis Taking stores of glycogen to glucose which is the simplest molecule to breakdown, giving almost instant energy for performance.

13

PE Unit 4 Anaerobic Training… - Cardiovascular

• Blood Pressure - Increase in Vascularisation Body tissue becomes vascular and develops capillaries, therefore more blood and oxygen can be transported around the body, therefore to working muscles.

• Blood - Decrease in Blood Pressure • Heart - Increase in Ventricle Thickness A thicker heart wall allows for more forceful contritions (more blood per systole), adding a small increase to stroke volume - Muscular

- Increase in Fibre Size (hyperplasia) Greater storage capacity for energy substrates, mitochondria and enzymes, furthermore increasing the strength of muscle contractions.

- Increase in ATP and PC Stores More energy available in muscles allows it to be used immediately as needed and for longer, improving performance.

- Increase in Glycogen Stores Enable muscles to continue working for longer requiring minimal oxygen and energy to break down, by being readily available in muscles, and my having more, athlete is less likely to use fats, decreasing performance.

- Increase in Glycolytic Enzymes It increases the rate the glycogen is broken down to ready to use glucose, by having this rapid breakdown, more easy energy is available quickly.

- Increase in Contractile Proteins Allow for greater contraction forces, the greater the size, there is more allowance for PC and ATP storage.

- Increase in Myosin ATPase Leads to rapid attachment to actin and contractions to take effect.

- Increase in Muscle Buffering Capacity/By-Product Tolerance Muscles are trained to adjust to the accumulation of by-products, by doing so, the athlete has a longer time period before reaching by-product related fatigue.

14

PE Unit 4

- Increase in Improved Motor Unit Recruitment The nervous system and the muscular system work in sync to allow more effective movements.

- Increase in Neural Transmission Increases you're reaction to stimuli.

- Increase in Speed and Force of Contraction Improves the quality of your performance

- Increase in Size of Connective Tissue/Tendons Leads to greater muscle size, assisting in force production.

- Decrease in Lactic Acid Production (sub-max) As you become more anaerobically trained, the production of H+ ions and lactate lessens, therefore you have a longer time till you reach your LIP, extending the period of high performance.

- Decrease in Recovery Times The time needed to recover after anaerobic performance decreases as the body becomes more able to resynthesis used fuels and recover. Chronic Adaptations: Long term physiological changes in response to increased demands placed on the body through training. Adaptations are wither functional or structural. Blood Direction: - Leaves heart (oxygenated) - Arteries - Arterioles - Capillaries (diffusion at capillary tissue interface) - Venuls - Viens - Back to the heart (un oxygenated) Heart Size: Non-Athlete - Normal size heart and ventricles Endurance Athlete - Bigger heart and ventricles with think ventricle walls Non-Endurance Athlete - Bigger heart with normal ventricle walls Myoglobin and Haemoglobin: - Haemoglobin collects oxygen that has diffused through the alveolar-capillary interface from the alveolar (lungs) to the blood stream - Carries it on red blood cells - Oxygen diffuses from the blood stream to the muscle through the tissue/musclecapillary interface - It is then taken by the myoglobin on the membrane of the muscle inside to the mitochondria.

15

PE Unit 4 Muscle Fibres: - Slow twitch fibres (STF) - Aerobic - Fast twitch fibres IIA (FTFIIA) - Aerobic and anaerobic - Fast twitch fibres IIB (FTFIIB) - Anaerobic V=TVxRR: V- Amount of oxygen taken in per minute TV- Volume of air in each singular breath RR- Breaths per minute Q=SVxHR: Q= Amount of blood ejected from the heart per minute SV= Amount of of blood ejected from the left ventricle per beat HR= Amount of heat beats per minute Hypertrophy: Increased capillary density around the fibre (Slow twitch take up more muscle area than fast twitch in endurance athletes).

Performance Enhancement and Recovery Practices 3-4 hours prior to exercise

1-2 hours prior to exercise

Immediately before, or during exercise

• • • •

• • • •

• • • •

Pasta Breakfast Cereal Potatoes Fruit Salad

Fruit Smoothie Banana Breakfast Cereal Yoghurt

Sports drink Carbohydrate gel Sports bars Jelly lollies

Carb Loading… Purpose - To prolong CHO as the main fuel and delay the bodies reliance on fats (due to depletion of glycogen) by maximising liver and muscle glycogen stores - Fats require more energy/oxygen to break down Involves changes to… 1. Training (tapering 3-4 days) - reduction in training volume not intensity (as energy system focus would change) 2. Diet (high consumption of CHO: 7-10g/kg of body weight - causes a 200-300% increase. Important considerations…

- Requires an exercise taper - hard 3-4 days before competition - Failing to rest will compromise CHO loading - It can be hard to eat enough, and the rest food - get a dietitian - Limit fibre intake (stomach upsets/too bulky) - sport gels, cordial, soft drink, honey, tinned fruit

- Expect up to 2kg increase due to muscle glycogen and water storage increase 16

PE Unit 4 The Glycemic Index…

- Ranks food from 0-100 according to how much the raised blood sugar over a 2 hour period, compared to pure glucose

- A GI score of 70 means the food will raise blood sugar by 70% as much as pure glucose would in 2 hours.

- Low GI foods consumed as a meal 3-4 hours prior to an endurance activity (60+minutes) lead to minimal changes in blood glucose and insulin levels and lead to glycogen sparring due to fatty acid availability

- High GI (and some medium) foods quickly replenish carbohydrate stores during recovery Performers should have a…

- 3-4 hours prior — high CHO meal, low GI - 1-2 hours prior — High CHO snack

Limit fibre (gastric upsets), low fat

- During — High GI, carbohydration - After — High GI (within 30min) and some protein (to aid muscle recovery) High GI Foods • • • • • • •

Medium GI Foods

White Bread Wholemeal Bread Rice Pumpkin Bananas Dates Honey

• • • • • • •

Low GI Foods

Pancakes Carrots Potatoes Oranges Muesli Bars Potty Chips Muffins

• • • • • • •

Oats Muesli Baked Beans Pears Nuts Yoghurt Lentils

CHO During Recovery…

- First two hours of recovery - blood still being sent to muscles in large quantities and muscles are still receptive to taking up glucose and enzymes conductive to converting glucose to glycogen

- High GI foods and sports drinks will provide glucose to muscles quickly. Drinks aid with hydration

- Important to try and maximise glycogen replenishment within 30 minutes after exercise Time of consumption after event/ activity

Time required for glycogen replenishment 6 hours

24 hours

48 hours

72 hours

Before 30 mins

50%

100%

1-2 hours

30%

70%

100%

3+ hours

10%

60%

90%

17

100%

PE Unit 4 CHO Refuelling During an Event…

- High GI recommended so that glucose can be absorbed quickly and be ready for use - Sports drinks are ideal as they have the added benefits of hydration and electrolyte replacement Carbohydrate Gels…

- Dehydrated sports drink - Must be consumed with water — otherwise will not absorb quickly enough to ‘top up’ fuel stores

- Consuming gel and sport bars together should be avoided when high sea rates occur because the large increase in carbohydrate concentration and resultant slowing ofuydration levels Orally: Consuming the substance through the mouth Intravenous: Administrating the fluid through a vein Eg- When athlete is unconscious or unable to to drink due to injury or stress • Must be in hygienic conditions, unless managed correctly, over hydration can occur • In 2006, WADA made it illegal unless for legitimate reasons

Dietary Supplementation… A dietary supplement is something added to an individuals diet to try to increase performance,it is either natural or manufactured Protein Supplementation - Used to increase muscular power and strength. They aim to…

- Provide material to construct and repair muscle cells - Provide the 20 necessary amino acids to support the immune and endocrine systems - Increase the transmission of nerve signals around the body - Help to achieve the resynthesis of glycogen Caffeine Supplementation - It was one on the WADA banned list when over a certain amount is consumed but was removed in 2004.

- It works to stimulate the CNS allowing for stronger neural transmissions - Believed to have a glycogen sparing affect - Believed to delay/reduce fatigue levels in the muscles - Improved contractility

18

PE Unit 4 Hydration… It is important to stay hydrated as we loose fluid through sweating (plasma loss). To replace the plasma, hydration is key. It can be done through water and/or sports drinks Sports Drink - Work to rehydrate the body, replace electrolytes lost in sweat and replenish carbohydrates. There are three types of sports drinks… Isotonic:

• Same osmolarity as the bodies fluid (eg blood plasma. • Used by athletes to balance their refuelling (glucose) and rehydration (water) Hypotonic:

• Low osmolarity due to lower concentration of CHO and electrolyte particles • Drink is more diluted, absorbed at a faster rate than isotonic • Useful to quickly replenish fluids lost though sweat but not for CHO or electrolyte boost Hypertonic:

• Higher osmolality — more concentrated than bodies fluids • Absorbed slower than isotonic drinks • Contain more CHO — useful to replenish glycogen stores after exercise • Ultra-distance events — can be used but must be in conjunction with isotonic drinks that will replace fluids Contain water, CHO and electrolytes Osmolality: Concentration of solutes (CHO, electrolytes) in the solution compared to the bodies plasma Rate of hydration is dependant on the sleep at which it is emptied from the stomach into the small intestine and then absorbed through the walls of the small intestine into the blood. Higher the CHO concentration, slower the rate of absorption Electrolytes reduce urine output, enable fluid to empty quickly from the stomach, promote absorption from the intestine and encourage fluid retention

Type

Osmolality compared to blood plasma

Concentration of carbohydrate (g/100mL)

Isotonic

similar number of particles

4—8

Hypotonic

fewer particles

8

Water - Works to replace lost blood plasma lost in sweat. Can be consumed either orally or through an intravenous drip (IV). WADA banned the IV in 2006 unless medically needed

19

PE Unit 4 Avoiding Dehydration.. Acclimatisation

Allowing the body to become used to different environments (heat/humidity). If an athlete spends 5 days in a humid environment slowly increasing their intensity the body with become someone used to that environment. Being better at conserving fluid.

Heat Training

Regular training in hot conditions can lead to the body becoming more tolerant to hot conditions and less likely to become dehydrated.

Modify Training

If training occurs on an extremely hot/humid day, it should be modified to reduce dehydration chance. This could be lessening the duration, the intensity with more hydration opportunities.

Wearing Correct Clothing

Clothing should be loose fitting, light weight and ligh...