Abstract
This study investigated blood pressure responses (BP) during bilateral leg extension
in healthy children at different numbers of repetitions. BP was measured non-invasively
during 1 repetition maximum (1RM), 5 repetitions at 85–90% of 1RM (5 R), 30 repetitions
at 35–40% of 1RM (30 R) and during 5 s of maximal isometric work (5SM). It is important
to investigate if maximal strength testing in healthy children provokes an unfavourable
rise in BP, in order to be able to do further research on hypertensive risk groups
of children. 39 (18 male and 21 female) healthy children (10.5±2.0 years old) participated
in this study. Peak BP values and peak HR increased significantly with increasing
number of repetitions. Peak BP increased from 1RM (144±16/110±19 mmHg) to 30R (170±26/123±21 mmHg)
and peak HR increased from 1RM (122±10 bpm) to 30 R (147±14 bpm). 30R also gave significantly
higher BP and HR than 5SM (156±24/120±23 mmHg and 131±16 bpm, respectively). The boys
had significantly higher diastolic BP during 1RM than the girls and significantly
higher BP during 5SM. In conclusion, maximal strength testing induced lower increases
in BP than submaximal strength testing with more repetitions, and may be performed
in healthy children within safe BP limits (< 225 mmHg in systolic BP).
Key words
strength testing - adolescents - knee extension - haemodynamics
