The Science & Evidence

Does mental training actually work? What the research shows.

PPR draws on decades of research into breathing, attention and resilience. This page summarises that evidence honestly — including where it is thin. Every figure below describes studies of related practices in other populations, not measured outcomes of the PPR app.

Last updated: 10 July 2026 · Figures describe research on related practices — full citations at the foot of this page.

Is psychological resilience real — and can it be trained?

The American Psychological Association defines resilience as "the process and outcome of successfully adapting to difficult or challenging life experiences," involving "behaviors, thoughts, and actions that can be learned and developed in anyone" [American Psychological Association, "Resilience," accessed 2024].

A systematic review and meta-analysis of 11 randomised controlled trials found a moderate positive pooled effect of resilience-training interventions (SMD 0.44, 95% CI 0.23–0.64). Cognitive-behavioural, mindfulness-based and mixed programmes were all effective, and combining CBT with mindfulness had a positive impact on individual resilience [Joyce et al., BMJ Open, 2018].

Honest note: these effects are moderate, heterogeneous and mostly short-to-medium term. "Trainable" is well supported; "guaranteed," "large" or "permanent" are not.

Why does slow breathing calm you down?

Breathing at about six breaths per minute produced "highly significant increases in baroreflex sensitivity" and reduced sympathetic (fight-or-flight) activation in a study of 81 chronic-heart-failure patients and 21 controls [Bernardi et al., Circulation, 2002].

A breathing rate near 5.5–6 breaths per minute — the "resonance frequency" — produces the largest oscillations in heart-rate variability by synchronising the breath with the body's blood-pressure (Mayer) waves. This is the pace used in HRV-biofeedback training [Steffen et al., Frontiers in Public Health, 2017]. Slow-paced breathing at roughly six cycles per minute has been documented as a validated, low-risk way to raise vagal (parasympathetic) activity [Laborde et al., Psychophysiology, 2022].

Honest note: the same 2017 analysis found non-significant effects on systolic and diastolic blood pressure, even though mood and HRV measures improved. Slow breathing is a self-regulation practice — it is not a treatment for high blood pressure, and PPR makes no blood-pressure claim.

Can mental training protect attention under stress?

Marines who practised roughly 12 minutes a day of mindfulness during a high-stress pre-deployment interval maintained or improved their working-memory capacity, while those who practised little — or were untrained — declined [Jha et al., Emotion, 2010].

Across two military cohorts, training-focused mindfulness "curbed attentional lapses" and protected sustained attention compared with didactic-only or no training [Jha et al., PLOS ONE, 2015]. Focused-attention and open-monitoring practices are two well-described families of attention training that engage measurable attention networks [Ainsworth et al., Psychiatry Research, 2013].

Do pilots and aviators really train the mind this way?

A one-year intervention with two-year follow-up in a high-performance combat-aviation (F-16) population found pilots reported increased mindfulness and better attention- and arousal-regulation skills — describing the state as "being fully in the now" and "relaxed, calm — but fully awake" [Meland et al., The International Journal of Aviation Psychology, 2015]. A related study in a military helicopter unit paired self-report with physiological stress measures and objective attention-control tasks [Meland et al., 2015].

Honest note: aviation samples are small. The results are encouraging for performance-relevant self-regulation — not evidence of clinical benefit, and not a claim about anyone's flying or combat performance. PPR is an independent app and is not affiliated with, or endorsed by, any air force.

Does meditation help with everyday stress, anxiety and sleep?

A meta-analysis of 47 trials (3,515 participants) found moderate evidence that mindfulness programmes improved anxiety (effect size 0.38 at 8 weeks, 0.22 at 3–6 months) and depression (0.30 at 8 weeks, 0.23 at 3–6 months), plus pain. The authors describe the effects as "small to moderate" [Goyal et al., JAMA Internal Medicine, 2014].

In workplaces specifically, a meta-analysis of 23 randomised trials found significant effects on stress (SMD −0.57), anxiety (−0.57), psychological distress (−0.56), depression (−0.48) and burnout (−0.36), plus improvements in wellbeing, sleep and job performance (0.43) [Bartlett et al., Journal of Occupational Health Psychology, 2019]. And a randomised trial in older adults with moderate sleep disturbance found a mindfulness programme improved sleep quality more than sleep-hygiene education [Black et al., JAMA Internal Medicine, 2015].

These findings describe structured mindfulness programmes in research settings. They are not claims that PPR treats, prevents or cures anxiety, depression, insomnia or any condition. If you are struggling, please seek qualified professional care.

Honesty first

What the evidence does NOT show

How does this research relate to PPR?

PPR draws on a long tradition of mental-training practice with a fighter-pilot heritage. The evidence above describes that tradition and its mechanisms in other populations. Think of this page as the "why it is reasonable" behind the method — with the honesty section above as the essential counterweight.

See the full six-module method →   Why high performers use PPR →

Citations

Full source list

Every substantive claim on this page maps to a source below. Figures describe the cited studies, not PPR. Last checked 10 July 2026.