graded exercise test

grad·ed ex·er·cise test

(GXT) (grād'ĕd eks'ĕr-sīz test) Multistage exercise testing (usually on treadmill or bicycle ergometer) in which exercise intensity is progressively increased (graded) through levels that bring the test subject to a self-imposed fatigue level.
See: stress test, Astrand-Ryhming Cycle Ergometer Test