||Abstract: "Similar increases [following exercise] in (p <.01) cardiolipin (88.2 +/- 9.0 to 130.6 +/- 7.5 microg/mU creatine kinase activity [CK]) and the total mitochondrial DNA (1264 +/- 170 to 1895 +/- 273 copies per diploid of nuclear genome) reflected increased mitochondria content." P.536 right column 3rd paragraph: "Mitochondria content: Skeletal muscle mitochondria DNA (mtDNA) content was determined in biopsy samples before and after the intervention, and the results are shown in Figure 1. At baseline, muscle mtDNA was lower in these elderly men and women in comparison to younger adults recently reported in [investigators'] laboratory (ref 24), which is also consistent with prior studies (ref 3). Changes in mtDNA reflect changes in mitochondria volume. As illustrated in Figure 1, there was a robust increase (53 ± 15%) in mtDNA content with training (P<0.01). Cardiolipin, a mitochondria-specific phospholipid that reflects mitochondria content, increased by 56 ± 13% (Figure 2), corresponding to the increase in total mitochondria content assessed by mtDNA."