Why does vital capacity decreased during exercise

A spirometer is an important in the assessment of the lung functions. Subjects aged 18—50 years were recruited. Informed consent was taken from each after they had been given a detailed explanation of the experiment. The subjects were asked to complete questionnaires on medical history to ensure they are in a good health no acute illnesses related to respiratory or heart disease.

They are often used to measure the efficacy of an intervention and can be considered comparative cross-sectional. For this study, 72 male subjects were randomly selected by simple random sampling technique SRS. Measurements of respiratory indices were taken three times in the pre- and post-exercise phases of each session, and their mean values were used for analysis.

Subjects were asked not to change their habitual physical activity during the study and not to take any nutritional supplements. Each session began with a warmup period of five minutes. For the session itself, running time started at five minutes, and this interval was increased by ten minutes every three sessions, up to a maximum of 25 minutes. Subjects had to remain in the straight sitting or standing position throughout the test, and a nose clip was tightly attached to the nostrils, allowing no air to escape during the test.

FVC Maneuver: Each subject was asked to inhale completely and rapidly, pausing less than one second at total lung capacity TLC , and then exhale as quickly and completely as possible, expelling all the air.

MVV maneuver: Subjects were tested in the sitting position while wearing a nose clip. They were instructed to breathe as rapidly and deeply as possible for 12 seconds after obtaining at least three resting tidal breaths with an airtight seal around the mouthpiece.

Statistical analysis was conducted using SPSS software version The Wilcoxon test, a nonparametric analysis paired t-test , was done to determine changes pre- to post-test.

Table 1 shows the mean of the anthropometric characteristics of the 72 subjects. The mean age was Table 2 shows the baseline spirometry data of predicted values for the 72 subjects. The mean predicted FVC was 4. The mean pre-exercise FVC was 3. Post-exercise mean FVC after 5, 15, and 25 minutes was 3.

The post-exercise mean FEV 1 after 5, 15, and 25 minutes was 3. Table 3 B shows the baseline spirometry data of MVV before and after exercise at different intensities. The pre-exercise mean MVV was Table 4 shows the paired t-test. Double Your Gift. Your tax-deductible donation funds lung disease and lung cancer research, new treatments, lung health education, and more.

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Select your location to view local American Lung Association events and news near you. Our service is free and we are here to help you. Exercise and Lung Health. Section Menu. How Does Exercise Strengthen the Lungs? The Benefits of Exercise Exercise has lots of benefits for everyone, whether you are young or old, slender or large, able-bodied or living with a chronic illness or disability. What Types of Exercise and How Much? Some Things to Keep in Mind Always talk to your doctor before you start or modify your exercise routine.

This is especially important if you have an underlying health condition. Avoid exercising outdoors when pollution levels are high. When the air is bad, walk indoors in a shopping mall or gym or use an exercise machine. Improved cardio-respiratory function means that the body is able to perform exercise much more efficiently.

This results mainly from the body more effectively getting oxygen into the blood stream and transporting it to the working muscles, where it is needed for the metabolic processing of energy. In other words, the regular exerciser's body is much more proficient at loading, transporting and utilizing oxygen. He thus finds exercise such as climbing stairs far less strenuous than a person who does not exercise and is out of shape. Improvement in cardio-respiratory function does not result from changes in the lung's ability to expand, however.

In general regular exercise does not substantially change measures of pulmonary function such as total lung capacity, the volume of air in the lungs after taking the largest breath possible TLC , and forced vital capacity, the amount of air able to be blown out after taking the largest breath possible FVC.

So even though people often report feeling out of breath or winded during exercise, it is unlikely that pulmonary function limits their ability to exercise, unless they have a disease that specifically impairs lung function such as asthma, bronchitis or emphysema. One of the largest differences between an exerciser and a nonexerciser concerns the heart's ability to pump blood and consequently deliver oxygen to working muscles.

Cardiac output is a major limiting factor for prolonged exercise. In addition, an exerciser typically has a larger blood volume, is better able to extract oxygen from the air in the lungs and is better able to extract oxygen from the blood at the working muscles than a sedentary individual is. Gas exchange involves not only oxygen delivery but also the removal of carbon dioxide, which is a byproduct of energy metabolism, and this process is also more efficient in an exerciser. When all is said and done, regular exercise produces numerous favorable changes that collectively result in the body being able to work in a far more efficient manner.