Study of the response of lactic acid to the competition effort of 400m freestyle runners and its effect on the mechanisms of fatigue

Abstract

In this research (a study of the response of lactic acid to the competition effort of 400m freestyle runners and its effect on the mechanisms of fatigue) was carried out. The research sample consisted of 400m runners, who represent the Iraqi youth team, who numbered (6) runners, and they were chosen intentionally, and the descriptive method and the survey method were used. The aim of the research was Identifying the effect of competition effort on the lactic acid response of individuals in the research sample. And to identify the effect of competition effort on the level of concentration of the investigated variables. While the research hypothesis was that there were statistically significant differences between the pre- and post-measurements of the variables investigated for the individuals in the research sample, the researcher concluded that lactic acid and its salts (lactate) are not the main causes of muscle fatigue. Low concentrations of blood electrolytes (Na+, K+) in the post-tests may give An indication of its contribution to the causes of muscle fatigue. Especially its relationship to the mechanism of muscle contraction. The researcher recommended the necessity of using modern techniques (field laboratory devices), which are measured in the field and directly, to estimate the intensity of the physical load on the athlete, and the necessity of conducting other studies for 400m runners, to search for other causes of muscle fatigue, such as studying the role of calcium ions ( Ca++) or the role of acetylcholine and the enzyme cholinesterase, and we cannot fail to mention the psychological aspect and its role in muscle fatigue.