Breathing Sessions

Feelmo's breathing sessions offer six visual breathing pacers. A pacer is simply a timing guide: the circle expands for an inhale and shrinks for an exhale. You can use the patterns to explore which pace feels comfortable, but the app does not guarantee relaxation, sleep, focus, energy, or a change in heart rate variability (HRV) — the variation in time between heartbeats.

When might I use a session?

You might choose a short session when you want to pause, direct attention to breathing, or try a steadier rhythm. Your Balance score does not tell you that you need a breathing exercise, and a low score is not proof of stress.

Try one or two sessions only if the pattern feels comfortable. It is fine to stop early, return to natural breathing, or decide that paced breathing is not useful for you.

What are the six patterns?

The names below describe Feelmo's pacing options. The suggested uses are not medical indications, and the slow-breathing research cited later does not establish a separate benefit for every pattern.

Session	Pattern	Evidence boundary
4-7-8 Breathing	Inhale 4 seconds, hold 7, exhale 8	The breath hold may not suit everyone; it is not established here as a treatment for insomnia
Box Breathing	Inhale, hold, exhale, and hold for equal counts	A structured timing option, not a proven focus test or treatment
Calm Breathing	A slower paced pattern	"Calm" is the session name, not a guaranteed effect
Energy Breathing	Feelmo's more active pacing option	"Energy" is the session name, not a measured increase in energy
Sigh Breathing	Two inhales followed by a longer exhale	One breathing pattern studied experimentally; results do not guarantee an individual effect
Coherent Breathing	Inhale 5.5 seconds, exhale 5.5 seconds	About 5.5 breaths per minute; not necessarily the pace that creates the largest HRV oscillation for you

How to use the pacer

1. Open a breathing session from Home or another entry point, then choose a pattern.
2. Let the breath loosely follow the expanding and shrinking circle.
3. Keep the breath comfortable rather than unusually deep.
4. Stop and return to normal breathing if you feel dizzy, short of breath, chest tightness, tingling, or distress.

The session can appear on the lock screen as a Live Activity. You do not need to watch continuously or match every second. This is a pacing aid, not a treatment.

Why can breathing change HRV?

HRV means variation in time from one heartbeat to the next. Heart rate commonly speeds slightly during inhalation and slows during exhalation; this breathing-linked pattern is called respiratory sinus arrhythmia (RSA). Despite the word "arrhythmia," RSA is the name of a normal respiratory pattern, not a diagnosis of an abnormal heart rhythm.

Breathing also interacts with the baroreflex, the body's short-term reflex for stabilizing blood pressure. At slower rates, breathing-related heart-rate and blood-pressure oscillations can become larger. This can increase HRV while the person is following the pace.

A 2022 systematic review and meta-analysis included 223 studies. On average, vagally mediated HRV — measures particularly influenced by breathing-linked parasympathetic input to the heart — increased during voluntary slow breathing, immediately after a single session, and after multi-session interventions (Laborde et al., 2022).

This finding needs careful interpretation:

• The tested protocols, participants, breathing rates, outcomes, and study quality varied.
• Around six breaths per minute is common in research, but an individual's resonance rate can differ.
• A larger breathing-linked HRV oscillation is not a direct measurement of whole-body autonomic balance.
• An HRV increase during paced breathing partly reflects the breathing pattern itself. It does not by itself prove calm, improved health, better sleep, or treatment of a condition.
• The meta-analysis did not validate Feelmo's exact sessions or proprietary Balance score.

Current HRV guidance likewise cautions that HRV is not a specific measure of cardiac sympathetic output or a simple sympathetic-to-parasympathetic balance (Carter et al., 2026).

Is breathing the only way to influence the autonomic nervous system?

No. Breathing is unusual because people can voluntarily change its rate and depth even though it is also regulated automatically. That makes it a practical way to alter some cardiovascular rhythms. It is not the only influence on autonomic activity: posture, movement, exercise, temperature, sleep, medication, illness, and many other factors also matter.

It is therefore more accurate to call breathing one accessible input to the system, not a direct control switch for the whole autonomic nervous system.

What about cyclic sighing?

One randomized study reported average improvements in mood and reduced respiratory rate after brief daily structured breathing, with an exhale-focused cyclic-sighing group showing the largest mood improvement among the studied groups (Balban et al., 2023). This was one protocol and group comparison. It does not establish that every sigh session works immediately, treats anxiety, or matches Feelmo's implementation exactly.

Comparing your own records

Feelmo Premium's habit association patterns help you review observational relationships between breathing sessions you logged and Balance. Proprietary processing details are not public. The display cannot establish that a session caused a score, sleep, or symptom change.

Apple Watch / HealthKit measurements also have limits. Optical wrist signals can be affected by movement and contact; sample timing and duration vary; and breathing itself changes HRV. Feelmo's Balance score is proprietary and is not a direct autonomic or treatment-outcome measure.

References

1. Laborde S, Allen MS, Borges U, et al. Effects of voluntary slow breathing on heart rate and heart rate variability: A systematic review and a meta-analysis. Neuroscience & Biobehavioral Reviews. 2022;138:104711. doi:10.1016/j.neubiorev.2022.104711. PMID: 35623448.
2. Carter JR, et al. Guidelines for rigor and reproducibility of heart rate variability within human cardiovascular research. American Journal of Physiology-Heart and Circulatory Physiology. 2026. doi:10.1152/ajpheart.00041.2026. PMID: 42495990.
3. Lehrer PM, Gevirtz R. Heart rate variability biofeedback: how and why does it work? Frontiers in Psychology. 2014;5:756. doi:10.3389/fpsyg.2014.00756.
4. Zaccaro A, Piarulli A, Laurino M, et al. How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing. Frontiers in Human Neuroscience. 2018;12:353. doi:10.3389/fnhum.2018.00353.
5. Russo MA, Santarelli DM, O'Rourke D. The physiological effects of slow breathing in the healthy human. Breathe. 2017;13(4):298–309. doi:10.1183/20734735.009817.
6. Balban MY, Neri E, Kogon MM, et al. Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine. 2023;4(1):100895. doi:10.1016/j.xcrm.2022.100895.