Exercise induces a number of cardiovascular and respiratory responses to occur inside the body (1). As exercise commences the demand for oxygen rises in order for the body to continue providing energy for muscular function. To do this, oxygen uptake increases linearly to match skeletal muscle demand, until maximum oxygen consumption is reached (2). Ventilation will increase so more oxygen is being consumed and more carbon dioxide (CO2) is offloaded; cardiac output (the product of stroke volume and heart rate) and blood pressure will also increase to pump the required oxygen around the body (1,2). Vasodilation will also occur peripherally as blood flow to the working skeletal muscles increases in order to supply more oxygen, and remove carbon
…show more content…
While Louvaris et al proposed that an increase in peripheral blood flow might not be necessary as the increase in arterial oxygen concentration may be sufficient for oxygen demand (13). Another study using patients with chronic heart failure suggested that oxygen supplementation did improve exercise performance, with a dose-related response (14). This study found that exercise duration increased with higher concentrations of oxygen, as respiratory rate and heart rate decreased and oxygen delivery increased due to peripheral blood flow (14). These results contradict those found in our study, which may be an indication of the differences that oxygen supplementation may have between healthy and cardiorespiratory impaired individuals. It has been hypothesized that oxygen consumption is independent of the amount of oxygen inspired in healthy subjects (14). This means that exercise improvement in these individuals must depend on something other than improving oxygen delivery to the active muscles, as hypoxia is less of an issue (14). Whereas in disease-states such as COPD hypoxia is an issue from the beginning of exercise and therefore oxygen may …show more content…
However, future improvements include for it to be repeated using a larger sample size of various aged individuals and an even ratio of males and females. A mixture of subjects with and without cardiorespiratory conditions may also be necessary so any differences between oxygen supplementation on the groups can be determined. A more rigorous experimental protocol involving exercising for longer at a higher intensity, to stimulate the hypoxic drive for ventilation, is required, as well as better techniques in measuring peripheral blood flow and respiratory rate. These are essential for future studies, to improve the reliability of the results. Only when this has been conducted could it be concluded whether or not oxygen supplementation is an effective treatment for exercise capacity in individuals with cardiac or respiratory
While Louvaris et al proposed that an increase in peripheral blood flow might not be necessary as the increase in arterial oxygen concentration may be sufficient for oxygen demand (13). Another study using patients with chronic heart failure suggested that oxygen supplementation did improve exercise performance, with a dose-related response (14). This study found that exercise duration increased with higher concentrations of oxygen, as respiratory rate and heart rate decreased and oxygen delivery increased due to peripheral blood flow (14). These results contradict those found in our study, which may be an indication of the differences that oxygen supplementation may have between healthy and cardiorespiratory impaired individuals. It has been hypothesized that oxygen consumption is independent of the amount of oxygen inspired in healthy subjects (14). This means that exercise improvement in these individuals must depend on something other than improving oxygen delivery to the active muscles, as hypoxia is less of an issue (14). Whereas in disease-states such as COPD hypoxia is an issue from the beginning of exercise and therefore oxygen may …show more content…
However, future improvements include for it to be repeated using a larger sample size of various aged individuals and an even ratio of males and females. A mixture of subjects with and without cardiorespiratory conditions may also be necessary so any differences between oxygen supplementation on the groups can be determined. A more rigorous experimental protocol involving exercising for longer at a higher intensity, to stimulate the hypoxic drive for ventilation, is required, as well as better techniques in measuring peripheral blood flow and respiratory rate. These are essential for future studies, to improve the reliability of the results. Only when this has been conducted could it be concluded whether or not oxygen supplementation is an effective treatment for exercise capacity in individuals with cardiac or respiratory