Is HRV worth prioritizing?

A 2017 meta-analysis found HRV biofeedback training — deliberately practicing slow, paced breathing to increase heart rate variability — produces a meaningful reduction in self-reported stress and anxiety, a mechanism-consistent finding supported by a separate meta-analysis showing voluntary slow breathing reliably increases HRV. Weighing that against the numbers, HRV is not a priority based on current data — the evidence is only moderate (70/100), and its estimated impact (50/100) is on the lower end too.