Regarding the nonsignificant increase of PGC-1α in the HIIT+MI group compared to the HIIT group in the present study, it can be concluded that PGC-1α may be suppressed at first in some conditions such as heart attack, but it can finally act as a compensatory response to the rapid decrease in energy. The gene discussed is PPARGC1A; the disease is myocardial infarction.