Positives

• Patients who stick with HRV biofeedback often describe it as a real autonomic-regulation tool, especially when they pair coherent breathing with a chest strap and an app such as Elite HRV. Reddit.

Negatives

• The response is not uniformly positive: some people say resonance breathing makes their HRV numbers worse or leaves them feeling more off instead of calmer. Reddit.

Hurdles & Side Effects

• The practical barrier is setup and protocol choice, because patients end up comparing chest straps, breathing cadences, and HRV apps before they know whether the method fits them. Reddit.