Responses To Steady-State Exercise
Once an athlete has been performing continuous exercise for a period of around 20 minutes, their body reaches a steady-state. Continuous exercise includes all forms of exercise that have no stopping periods such as jogging, swimming or cycling. Examples of non-continuous exercise would be weight lifting, interval training and boxing.
Steady state is when the body is working at a steady state it means that lactic acid removal is occurring at the same pace as lactic acid production.
Various changes will have occurred in the body to allow this steady state to occur.
Cardiovascular • Heart rate levels off • Increased stroke volume • Vasodilation of blood vessels leading to working muscles • Blood pressure levels off • Thermoregulation
Respiratory • Tidal volume levels off • Breathing rate levels off • Oxygen is unloaded from haemoglobin much more readily
Neuromuscular • Increased pliability of muscles • Increased speed of neural transmissions
Energy • Aerobic ATP production
In cardiovascular response to steady state heart rate peaks during the first few minutes of exercise and then levels off. While exercising there is an increase in venous return. This increased volume of blood has the effect of stretching the cardiac muscle to a greater degree than normal. This stretching has the effect of making the heart contract much more forcibly and thereby pumping out more blood during each contraction, so stroke volume is increased during exercise. This effect is known as starling’s law.
The average cardiac output is around 5 litres per minute. When this blood is circulated around the body, some organs receive more blood than others. However, during exercise, the working muscles need a greater proportion of blood in order to supply them with energy. The body is able to redirect blood flow by constricting the blood vessels leading to organs