Abstract: To explore the effects of special training of varying altitude gradient as the control variable 12-minute running performance and body function indexes as observational variables of endurance athletes at altitude. Methods: Twenty-eight plateau endurance athletes were randomly divided into two groups, A and B. The 12-minute run test was performed after endurance training at different altitudes. Results:1) By controlling the change of training altitude gradient, there was a significant difference between the two groups in test results, among which the difference of slowest speed and heart rate was significant (P < 0.01); 2) the variation coefficient values of the exercise indicators in group A were maximized in the sub-plateau, reached the minimum in the plain, and the variation coefficient values of the difference values of some physical function indicators reached the minimum in the plain. Conclusion: the special combination training of different altitude gradients in plateau, sub-plateau and plain can effectively improve the 12-min running performance of plateau endurance athletes, effectively ensure the stability of their performance after arriving at the plain, and improve their sports ability, which was conducive to the plain competition.

Key words: Different Altitude Gradients, 12-minute Run, Plateau Endurance Athletes, Bodily Functions, Coefficient of Variation