[Comparative study of four effort tests on nine-year-old children. The value of systolic tension time (author's transl)].

Simple effort tests were carried out on 9-year-old children to measure the systolic tension time (STT) and to judge the accuracy and limitations of such a test by comparing it with other measures more commonly employed in France for the same age group: Pachon-Martinet, Ruffier-Dickson, and maximal oxygen uptake (VO2max), the latter (estimated indirectly) serving as the standard of reference. Subjects stepped onto and off a stool 40 cm high, 24 times per minute; immediately thereafter the heart rate per minute and the arterial systolic pressure (mm Hg) were measured, and the product (the systolic tension time) was obtained. At the age of 9 years, 95% of children have an STT of between 13 000 and 25 000. This test, besides the ease with which it can be performed in daily experimentation, has the advantage of giving results that are at once more precise and more significant than the two standard tests of Pachon-Martinet and Ruffier-Dickson because the quality of the experiment is more satisfactory, because autonomic factors have less impact, and because its discriminative value is higher since only the STT provides a satisfactory correlation with VO2max. The test also fulfills the various requisites of an effort test: it can help to trace a poor cardiovascular response to effort and, because of its selective nature, it can also provide a convenient means of supervision of young athletes. In practice, the test should be complemented by a study of the first 3 min of recovery, as this was the only part of the test showing a difference between boys and girls, whether trained or not.