The effects of moderate workload exercise at different pedal rates on circulatory and respiratory parameters were studied. Five subjects performed seven discontinuous constant-load cycle ergometer tests of 30 minutes duration at pedal rates of 40, 50, 60, 70, 80, 90 and 100 rpm. Oxygen uptake and carbon dioxide production were determined by standard open circuit spirometry, while heart rate was recorded by electrocardiograph. The CO₂ rebreathing procedure was administered during the exercise bout in order to determine cardiac output. Blood pressure was determined for each test, and total peripheral resistance was calculated. The findings indicate that progressive increases in pedal frequency during discontinuous constant-load cycle ergometry produce progressive increases in cardiovascular, respiratory and metabolic responses and a decrease in gross exercise mechanical efficiency. The results indicate that oxygen uptake, cardiac output, heart rate, ventilation and arterial-venous oxygen difference increases curvilinearly as pedal rate increases, possibly as a result of increases in recruitment of muscle fibers and/or muscle groups. These findings suggest that circulatory and respiratory responses are due to "central command" which sets the basic efferent response pattern. However, this effector pattern is modulated by afferent input originating from the legs during progressive increases in pedal rate.

The thesis is focused on the comparison of functional examination of the patients lungs, before and after coronavirus disease 2019 (COVID-19), as well as on the comparison of physiological data for a individual person with measured values after the disease. The relationship between lung function and smoking, sex, age and time gap after COVID undergone was monitored. The screening was accomplished by spirometry in a pneumology surgery and the obtained data were processed in practical part of my thesis. The theoretical part of the diploma thesis describes the respiratory system and lungs functional testing. In addition, infectious disease COVID-19 is described herein. The aim of the thesis was to select suitable patients, who have suffered from the COVID-19 disease, but without other serious respiratory problems, make a measurements and statistically evaluate the correlation between the measured results. The experiment involved 66 people aged between 21-94, of which 43 were men and 23 women. It has been shown a predominantly negative effect of COVID-19 in the values of the examined indicators in spirometric measurements, similarly, the impairment was seen more in men than in women. The role of younger age has been proven in the better results of spirometric measurements. However, the differences in...