PE Chronic adaptations REVISION Q'S

Chronic adaptations

How long does it take to see an adaptation from training? Anaerobically/aerobically? Maximal oxygen consumption has been shown to increase with aerobic training. Improvements of around 5-20% can be achieved with 8-12 weeks of training (depending on the circumstances). Anaerobic training takes around 6-12 weeks to observe change. An increase in VO2 max (Maximal oxygen consumption) from aerobic training, results in an increase to what? Increases in cardiac output and haematocrit (ratio of the volume of red blood cells to the total volume of blood). The increase in the maximal oxygen consumption (VO2 max) is shown to be a result of a number of changes. Including an increase in oxygen delivering to the working muscles and an increase in ability of the muscles to extract the oxygen from the blood, that is, the a-vO2 diff. The increase in cardiac output is a result of an increase in heart rate and the stroke volume at maximal intensities; and the increase in a-vO2 diff is a result of changes within the muscle. Oxygen extraction also reaches maximum during high-intensity exercise.  Aerobic training and chronic adaptations to skeletal muscle Aerobic training increases the ability of the skeletal muscles to oxidise glycogen during maximal and sub-maximal exercise. Also results in an increased oxidation of fats at rest. Regular aerobic training may result in Increased ratio of high-density lipoprotein (HDL) to low-density lipoproteins (LDL). The LDLs carry cholesterol to the arterial walls and empty/deposit it there as plaque, which damages the arteries and causes narrowing of the blood vessels, hindering blood flow. The HDLs aim to combat this by removing the plaque from the arterial walls and delivering to the liver, where it can be synthesised. Define a-vO2 diff The difference in oxygen concentration between the blood in the arteries compared to the blood in the veins; it is a measure of the amount of oxygen the working muscles are using. Aerobic training leads to an increase in the a-vO2 diff, thereby allowing the working muscles receive more oxygen. Factors that affect the development of chronic adaptations to exercise Type and method undertaken; aerobic versus anaerobic training and different training methods lead to different adaptations The frequency, intensity and duration of training; the greater the frequency, intensity, and duration of the training, the greater the adaptations The individual's capacities and heredity factors; genetic make-up such as VO2 max and fibre type distribution.

Understand what affect training has on your heart rate, stroke volume and cardiac output; at rest, sub-maximal, and maximal intensity. Aeoribically and anaerobically. From aerobic training, heart rate will decrease, that is, resting heart rate and submax HR. Stroke volume will increase at rest and submax during aerobic training. If cardiac output stays the same but heart rate decreases, there must be an increase in stroke volume due to the increased ventricle size and increased diastolic filling time. From anaerobic exercise, stroke volume will remain unchanged even though the heart can eject more blood more forcefully from the left ventricle Cardiac output will remain unchanged at rest and submaximal exercise but will increase at max intensity as a result of aerobic training. Relationship between heart rate, stroke volume, and cardiac output Cardiac output refers to the amount of blood that is pumped out of the heart per minute. It is the product of heart rate and stroke volume; how often the heart beats per minute multiplied by stroke volume - how much blood is ejected from the heart with each beat. An increase in either heart rate or stroke volume result in an increase in cardiac output. Q = HR X SV Other cardiovascular adaptations to aerobic training Cardiac hypertrophy - increased left ventricle size and volume. With aerobic training comes increased capillarisation, which allows for improved blood flow to the heart, delivering more oxygen to the myocardium to meet it's energy demands. Blood flow to the heart, however, decreases at rest and at sub-maximal exercise. The heart rate also decreases during resting and sub-maximal activities, however, there is an decrease heart rate recovery time, meaning it takes less time for a trained athlete's heart rate to return it's original level. There is also a decrease in blood pressure, and there is an increase a-vO2 diff. Increased blood volume and haemoglobin levels. Also increased capillarisation of skeletal muscles.  How do these chronic adaptations lead to an increased performance for an endurance athlete (aerobic training)? Increased blood volume and haemoglobin levels result in greater oxygen carrying capacity by the blood, allowing for more oxygen to be delivered to the working muscles. A greater level of oxygen being delivered to the muscles means that more oxygen is available to be used by the aerobic energy system, this results in the athlete being able to perform at a higher intensity while still predominately relying on the aerobic system.

List types of training that an endurance athlete could undertake Fartlek,  long-interval, continuous training Explain the difference in ventilation levels for a trained athlete compared to an untrained person. Endurance trained athletes working at rest or are working at sub-maximal intensity have lower ventilation (amount of air breathed in or out in one minute) compared to that of an untrained athlete; this is due to the adaptations that have taken place which result in an improved level of oxygen extraction from the lungs into the blood stream, which therefore the athlete does not need to inhale/exhale as often in order to obtain the required amount of oxygen. (Ventilation is the product of tidal volume and respiratory rate). However, ventilation at maximal intensity, of a trained athlete, will increase following aerobic training due to the increase in tidal volume and respiratory rate, thus resulting in a greater amount of air to be in/exhaled in one minute.                V = TV X RR Difference between a trained and untrained individual in terms of extracting oxygen from the blood stream to muscles In an aerobic athlete there is increases such as capillary density with skeletal muscles; more blood and hence more oxygen is delivered directly to the working muscles. Another chronic adaptation involves the significant increase in myoglobin stores within the muscle which allows for greater storage of oxygen inside the muscle.  Chronic adaptations that occur due to anaerobic training Muscular hypertrophy; there is an increase in size of the myofibrils, enlarged muscle fibres which lead to greater strength, power and speed.  Also increased muscular stores of ATP and PC, thus resulting in an increased capacity of the ATP-PC system, with a greater release of energy, and faster restoration of ATP.  Also there is an increase in glycolytic capacity due to the increase in glycolytic enzymes and also due to the increase in glycogen stores, therefore the rate at which glycogen can be broken down into lactic acid increases and ultimately contributes to the capacity of the anaerobic glycolysis system.  There is an increase in the number of motor units for maximal contractions, which leads to a more forceful contraction which leads to more speed.  There is also increase in strength of tendons and ligaments, as a result of hypertrophy.

Define LIP The lactate inflection point refers to the point after which the rate of lactate accumulation in the blood exceeds the rate of removal from the blood. It is the last point when the rate of blood lactate removal is equal to the rate of production. What significance does the LIP have on performance? In terms of fatigue Athletes who are exercising at an intensity above their lactate inflection point will only be able to maintain intensity for a short time as they will be relying heavily on their anaerobic glycolysis system. The accumulation of metabolic by-products associated with the anaerobic glycolysis system will set in, in a relatively short time, producing fatigue. How does aerobic training affect your LIP Aerobic training affects your LIP, because sustained aerobic exercise will enable to an athlete to work at higher intensities for longer without exceeding their LIP, meaning that they are able to exercise predominately aerobically at higher intensities for longer periods due to more oxygen being delivered to the working muscles based on the chronic adaptations that have occurred.  Difference between aerobic and anaerobic training on cardiac hypertrophy Aerobic training results in an increase in the size of the left ventricle cavity an thickening of the ventricle walls. This allows for greater ventricular filling. The heart can then eject blood more forcefully from the left ventricle but the stroke volume remains unchanged. Similar to aerobic training, anaerobic training also results in an increase in the thickness of the ventricle walls. Chronic adaptations; define and distinguish between acute responses. What level do they occur at? Chronic adaptations are physiological changes that occur to various body systems as a result of training exercise undertaken over a sustained period of time. For example, three times per week for 8 weeks. These changes take several weeks to develop, are long lasting, and take a number of weeks to again return to original levels. Acute responses, on the other hand, are physiological responses that occur to various body systems immediately when exercise begins, and revert to pre-exercise levels at the commencement of the exercise.