These data are from a study to determine whether a certain training regimen can counteract bone loss in women with postmenopausal osteopenia. The data are strength measurements for five muscle groups taken before and after six months of training. LP -- leg press HF -- hip flexor HE -- hip extensor AB -- arm abductor AD -- arm adductor It's never easy deciding what to do with such data (even ignoring the lack of a control group!). One could perform five separate comparisons, but when you perform many tests, there's a good chance something will appear to be statistically significant if only because probability theory guarantees that 5% of the time the observed significance level (P value) will be less than 0.05 even when there is no effect. One possibility in situations like this is to construct a measure of "total strength", that is, the sum of all five measures, too, but I notice that LP will dominate the other measures. Another option is the Bonferroni adjustment, dividing the preferred significance level by the number of tests. In this case, since there are 5 tests, each would be performed at the 0.01 level of significance. Another way to perform the Bonferroni adjustment is to multiply each P value by the number of tests. Continuing this example, if the P value is multiplied by 5 and is still less than 0.05, then the P value before multiplication must have been less than 0.01, so the two ways of performing the adjustment are equivalent.