|
We, members of the International Working Group on Isometric Exercise, read with great interest the article by Pagonas et al. on the comparative effects of aerobic and isometric handgrip exercise (IRT). However, we believe the finding, that aerobic exercise induces reductions in blood pressure (BP), whereas isometric exercise training (handgrip) does not, to be compromised for several reasons: First, the groups were not matched at baseline for resting SBP (office SBP- Table 2) differed by an egregious 8.8 mmHg between IRT and aerobic groups. Millar et al.[1] showed, some years ago, that account must be taken of baseline BP values, when analysing training-induced changes. The probability that a 9-mmHg difference in resting blood occurred by chance in a properly randomized study is very remote; moreover, the authors reported that this difference was not statistically significant (P = 0.36). Because of these sizeable differences in baseline BP measures, the aerobic training group clearly had greater potential to regress to the mean. |
|