Chronic Response to Exercise.

Transcription

1 Definitions: When regular exercise bouts occur where the appropriate training methods and principles are applied over an extended period of time (ie. Months) the body responds to the stress placed upon it by producing chronic or long term changes that result in a measurable increase in fitness. It is these chronic changes that we will be focusing on. It is these long term training effects that the coach and athlete are seeking when regular and appropriately designed training is undertaken. The level of fitness improvement achieved will of course depend on a number of factors.

2 Skeletal Muscle Chronic Response Aerobic Training Effects * Mitochondria...Increased * Glycogen stores...increased * Myoglobin...Increased * Triglyceride stores...increased * Oxidation rate (triglycerides and glucose...increased * Anaerobic glycolysis... Decreased. Fibres type: Number FT- No change ST- No change Size FT - No change ST - Increased

3 Skeletal Muscle Chronic Response Anaerobic Training (ie. Speed\Power Training) * Increased stores of A.T.P. and C.P. * Increased level of A.T.P.- C.P. turnover. * Increased glycolytic capacity due to increased stores of glycogen. * Increased speed of muscle contraction. * Muscle hypertrophy brought about by increase in contractile proteins, increase thickness of FT fibres, muscle cell hyperplasia (increase number of fibres due to fibres splitting * Increase strength and amount of connective tissue, including ligaments and tendons. * Increased ability to recruit motor units and thus produce a more forceful contraction!

4 Cardio-Vascular Chronic Responses Cardiac hypertrophy. Sustained aerobic training results in the enlargement of the heart muscle itself. This results in an increased Stroke Volume Increased Capillarisation of the heart muscle = better oxygen delivery. Lower heart rate : Resting & Sub-maximally. This is due to increased stroke volume. Improved Heart Rate Recovery. Due to improved efficiency of CV system.

5 Cardio-Vascular Chronic Responses cont.. Increased Cardiac Output (Q) Q =HR x SV While cardiac output remains unchanged at rest and even during sub-maximal exercise regardless of training status, it does increase during maximal workloads. Increased Arterio -Venous Oxygen Difference Greater oxygen is extracted by muscles due to Increased levels of myoglobin and mitochondria. Increased Blood volume and Hemoglobin. Regular and sustained aerobic training may lead to total blood volume rising by up to 25 per cent (from 5.25 litres to 6.6 litres) for an average adult male. Increased capillarisation of skeletal muscle. Blood pressure normalisation. Lowered cholesterol and triglyceride levels.

6 Respiratory Chronic Responses Increased lung ventilation Regular aerobic training results in more efficient and improved lung ventilation. At rest and during sub-maximal exercise, ventilation may in fact be reduced due to improved oxygen extraction. However, during maximal workloads, ventilation is increased because of increased tidal volume and respiratory frequency. Pulmonary diffusion the ability of the blood to extract oxygen from the alveoli is also enhanced as a result of training. Increased maximum oxygen uptake Aerobic training results in an increase in the maximum oxygen uptake (VO2 max) during maximal exercise. This improvement can be in the range of 5 to 30 per cent Following a regular and sustained training program. Increased anaerobic or lactate threshold As a result of the adaptations that improve oxygen delivery and utilisation in the muscles, a higher lactate threshold

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