NPPA and Hypervolemia: In contrast, Kraemer et al. [100] reported no changes in baseline plasma ANP over an 8-day HA intervention, and Patterson [161] reported no statistically significant difference in resting baseline plasma ANP among 12 individuals after either 8 days or 22 days of an HA intervention, with a numerical increase of 32% apparent on day 22, which might be reflective of the sustained hypervolemia induced by their experimental model [162].