Investigation of mutual aerobic and lower limb muscular activity during cycling

The evaluation of physical activity is a complex task that requires performing an analysis of muscular activity and aerobic/anaerobic threshold and it is often difficult to observe and propose a single method. The purpose of the article is to evaluate a relation between aerobic capacity and activity of lower limb muscles via changes of muscle's EMG signal during physical, sub-maximal veloergometric loading. The activity parameters of 5 lower limb muscles such as semitendinosus, rectus femoris, biceps femoris, gastrocnemius medialis, and tibialis anterior were measured and analyzed during the veloergometric exercise tests and the heart rate and the aerobic capacity were estimated from registered data. The obtained aerobic parameters allow setting an individual and overall voluntary physical capacity. The regression oxygen function presented allows analyzing and predicting the ability of subjects to generate energy while maintaining muscle activity during the exercise. The correlation between the consumption of oxygen and constant physical loading time is determined. It was found that comparing VO2max capabilities the physical effort in the male group was 16% higher than in women. Oxygen consumption and maximum muscle effort dependency on the load time was established. It was observed that the maximal muscular effort appeared before VO2max reached maximal limit in both groups. The maximal oxygen consumption is achieved in the middle or sometimes at the beginning (depending on load) of exercise while maximal muscular effort was found in several phases of cycling: at the beginning and at the end of loading time.