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Not medical advice

IRVO is a wellness app, not a medical device. It doesn't diagnose, treat or prevent any condition, and nothing in it is medical advice. Talk to a doctor before making any medical decision, and in an emergency call your local emergency number.

Every reading in IRVO compares you with your own recent days, not with other people. Here is what each one reads, and the research behind it.

Recovery

Recovery compares last night's heart rate variability (HRV), resting heart rate and sleep — total, deep and REM — with your own last 90 days. HRV below your usual, a resting heart rate above it and a short night are widely used signs that your body is less recovered than normal.

Sources

  1. Shaffer F, Ginsberg JP. An overview of heart rate variability metrics and norms. Front Public Health. 2017;5:258. (opens the source)
  2. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Heart rate variability: standards of measurement, physiological interpretation and clinical use. Circulation. 1996;93(5):1043–1065. (opens the source)
  3. Plews DJ, Laursen PB, Stanley J, Kilding AE, Buchheit M. Training adaptation and heart rate variability in elite endurance athletes: opening the door to effective monitoring. Sports Med. 2013;43(9):773–781. (opens the source)
  4. Buchheit M. Monitoring training status with HR measures: do all roads lead to Rome? Front Physiol. 2014;5:73. (opens the source)

Load

Load combines how your body looks today — HRV, resting heart rate and breathing rate against your own usual — with how demanding your calendar is: the kind of events, how long they run, how often you switch between kinds of work, and a short night before. The calendar weights are IRVO's own estimates, not clinical values.

Sources

  1. Buchheit M. Monitoring training status with HR measures: do all roads lead to Rome? Front Physiol. 2014;5:73. (opens the source)
  2. Monsell S. Task switching. Trends Cogn Sci. 2003;7(3):134–140. (opens the source)
  3. Van Dongen HPA, Maislin G, Mullington JM, Dinges DF. The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation. Sleep. 2003;26(2):117–126. (opens the source)

Sleep

IRVO treats under 6 hours as a short night and 7 hours or more as enough for most adults, in line with sleep-medicine consensus. Short nights in a row count for more, because the effects of losing sleep add up.

Sources

  1. Watson NF, et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep. 2015;38(6):843–844. (opens the source)
  2. Hirshkowitz M, et al. National Sleep Foundation's sleep time duration recommendations: methodology and results summary. Sleep Health. 2015;1(1):40–43. (opens the source)
  3. Van Dongen HPA, Maislin G, Mullington JM, Dinges DF. The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation. Sleep. 2003;26(2):117–126. (opens the source)

Mood

Mood comes from what you write. Each journal entry is placed on a scale from very low to very good, and your days are compared with your own usual — never with other people.

Sources

  1. Russell JA. A circumplex model of affect. J Pers Soc Psychol. 1980;39(6):1161–1178. (opens the source)
  2. Shiffman S, Stone AA, Hufford MR. Ecological momentary assessment. Annu Rev Clin Psychol. 2008;4:1–32. (opens the source)

Connections and patterns

Connections are patterns in your own data, not proof that one thing causes another. IRVO shows one only after at least 14 days, when it is unlikely to be chance and the effect is at least moderate, and it corrects for testing many pairs at once.

Sources

  1. Cohen J. Statistical Power Analysis for the Behavioral Sciences. 2nd ed. Routledge; 1988. (opens the source)
  2. Benjamini Y, Hochberg Y. Controlling the false discovery rate: a practical and powerful approach to multiple testing. J R Stat Soc Series B. 1995;57(1):289–300. (opens the source)

When a body note needs a doctor

If a body note mentions chest pain, trouble breathing, signs of a stroke, a sudden severe headache, fainting, coughing up blood or a severe allergic reaction, IRVO suggests getting checked. These are the symptoms public health services say need prompt medical attention.

Sources

  1. NHS. Chest pain. nhs.uk (opens the source)
  2. NHS. Heart attack. nhs.uk (opens the source)
  3. NHS. Symptoms of a stroke. nhs.uk (opens the source)
  4. NHS. Shortness of breath. nhs.uk (opens the source)
  5. NHS. Headaches. nhs.uk (opens the source)
  6. NHS. Fainting. nhs.uk (opens the source)
  7. NHS. Coughing up blood. nhs.uk (opens the source)
  8. NHS. Anaphylaxis. nhs.uk (opens the source)

If you're in crisis

If you tell IRVO you might be in danger, it points you to your local emergency number and to free, confidential helplines in your country.

Sources

  1. Find A Helpline. Free, confidential support from a helpline or hotline near you. findahelpline.com (opens the source)

Arcs

Arc plans are small, repeatable steps rather than big changes, because habits form through repetition over weeks. IRVO never suggests medication, supplements, doses, fasting or restrictive diets. For how much activity adults need, see the WHO's guidelines.

Sources

  1. Lally P, van Jaarsveld CHM, Potts HWW, Wardle J. How are habits formed: modelling habit formation in the real world. Eur J Soc Psychol. 2010;40(6):998–1009. (opens the source)
  2. Bull FC, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med. 2020;54(24):1451–1462. (opens the source)