Moreover, an overall increase was observed in the mRNA expression of the angiogenic factors examined, i.e., ANG-2, ANGPTL-4, VEGF-A, and HIF-1a ( p = 0.074), but again these changes failed to reach significance due to the large individual variation in the expression responses regarding these factors after the post-HIIT exercise program ( p > 0.05; Figure 2 c).
Physiological Adaptations and Performance Changes The variables VO 2 max, [La +2 ]peak, HRpeak , and PEs did not change significantly after the 8-week HIIT training compared with the baseline values ( p > 0.05), while PSVO 2 max marginally failed to reach statistical significance ( p = 0.062), ( Table 3 ).
However, the expression responses of these factors did not reach statistical significance as they exhibited a high variation among subjects, thus not permitting us to draw firm conclusions about their particular contribution to an angiogenic process post-HIIT program.