Long term effects of training. How the body adapts to aerobic training.

Important points to remember… The type of training effects the adaptions which take place Every individual responds differently because of their physiological make up. Physical capabilities are largely genetic No amount of training will change slow twitch fibres into fast twitch.

Aerobic adaptations After 12 weeks training you will have improved your VO2 max which is your bodies ability to sustain exercise. How?….

Adaptations to the heart. Hypertrophy Any muscle responds to training by increasing in size. As it gets larger it also gets stronger It is stronger and therefore can contract with more force.

Stroke volume and cardiac output SV at rest and exercise increases because of the hypertrophy of the heart. CO increases due to the increase in the size and strength of the heart. RHR falls due to the increase in SV.

Overall The heart becomes more efficient at pumping the blood around the body.

Adaptations to the lungs The maximum minute ventilation increases due to an increase in breathing rate and depth. Intercostal muscles become stronger and allow you to forcefully breath out. Lung volume cannot be changed but you can use more of what you already have. Gaseous exchange speeds up to meet the demands of the trained body.

Adaptations to blood Blood volume increases with endurance training. This is due to an increase in the plasma content of the blood and a small number of red blood cells. This means more haemoglobin is available to carry oxygen.

Blood acidity During sub maximal exercise the blood of the trained athlete is less acidic. They produce less lactic acid. During maximal exercise though endurance athletes have a greater resistance to the effects of lactic acid and more accumulates in the blood.

Adaptations to the vascular system Endurance training greatly increases the elasticity of the arterial walls. This allows the athlete to deal with greater fluctuations in blood pressure. The number of capillaries increases at the lungs and muscles helping to improve the rate of gaseous exchange.

Adaptations to the muscles Muscles increase in size and strength. Myoglobin in the muscle cell increases helping to transport oxygen to the mitochondria efficiently. Mitochondria in the muscles increase, this allows for greater rates of aerobic respiration to occur. Enzyme activity increases further improving the efficiency of the system The muscles store more glycogen and triglycerides, plus fat stores are mobilised more efficiently.

The overall benefits The following procedures become more efficient: External respiration Oxygen transport from the lungs to the cells Use of oxygen within the cells

VO2 max can improve by 20% therefore significantly improving the performance of activities that rely heavily on the aerobic energy system. Tendons become stronger Ligaments are stretched improving flexibility Exercise stimulates the deposition of calcium strengthening bones The lines of stress on bones are varied,