Biochemical changes and catecholamine responses in Down's syndrome adolescents in relation to incremental maximal...

The aim of this study was to determine biological responses in Down's syndrome subjects for an incremental exercise lasting 10 min. After a training programme specially adapted for children and adolescents with mental handicaps, 11 healthy Down's syndrome subjects, seven boys and four girls aged from 15 to 20 years, performed a progressive exercise until exhaustion on an ergometric bicycle. The results were compared with those taken from the literature for similar aged normal subjects. The results in our series of Down's syndrome subjects showed: (a) no differences in haematologic parameters, except for a high concentration of uric acid at rest which did not increase after the test; (b) a lower blood lactate level than in maximal exercise for this age range; (c) a late mobilization of FFA; and (d) a slightly lower maximal value of catecholamines. These results may suggest a reduced sympathetic response to maximal exercise.