References

The following references are for general scientific orientation. They do not replace medical advice and are not a complete bibliography. The evidence may change; the selection follows the sources cited on the respective service and self-test pages.

Within each topic, entries are sorted alphabetically by author. Articles and contributions follow the format: Chapter title. In: Title of the publication (journal or edited volume), with year, volume, issue and page numbers – written out, e.g. Band 38, Heft 3, S. 427–449. An access date is given only if an online link or DOI is provided.

As of: July 2026

IHHT altitude training

Source: /ihht-hoehentraining

1. Behrendt, T. et al.: Effects of Intermittent Hypoxia–Hyperoxia on Performance- and Health-Related Outcomes in Humans: A Systematic Review. In: Sports Medicine – Open. 2022; Band 8, Heft 1, S. 70. DOI: 10.1186/s40798-022-00450-x (accessed 21 July 2026).
2. Shabbir, R. et al.: Effectiveness of intermittent hypoxia-hyperoxia therapy for pain and general health in adults with musculoskeletal dysfunctions: Systematic Review and Meta-analysis. 2026 (advance/online publication; see the final publication for journal, volume and page numbers).
3. Uzun, A. B. et al.: Effectiveness of Intermittent Hypoxia–Hyperoxia Therapy in Different Pathological Conditions: A Narrative Review. 2023 (see the final publication for journal, volume and page numbers).

CO₂ dry bath / Medical CAT®

Source: /co2-trockenbad

1. Fabry, R. et al.: Clinical and microcirculatory effects of transcutaneous CO₂ therapy in intermittent claudication: Randomized double-blind clinical trial with a parallel design. In: VASA. 2009; Band 38, Heft 3, S. 213–224. DOI: 10.1024/0301-1526.38.3.213 (accessed 21 July 2026).
2. Hartmann, B. R.; Bassenge, E.; Pittler, M.: Effect of carbon dioxide-enriched water and fresh water on the cutaneous microcirculation and oxygen tension in the skin of the foot. In: Angiology. 1997; Band 48, Heft 4, S. 337–343. DOI: 10.1177/000331979704800406 (accessed 21 July 2026).
3. Prazeres, J. et al.: Effects of Carbon Dioxide Therapy on Skin Wound Healing. 2025 (see the final publication for journal, volume and page numbers).
4. Sakai, Y. et al.: A novel system for transcutaneous application of carbon dioxide causing an “artificial Bohr effect” in the human body. In: PLoS ONE. 2011; Band 6, Heft 9, S. e24137. DOI: 10.1371/journal.pone.0024137 (accessed 21 July 2026).

Longevity & Epigenetics

Source: /longevity-epigenetik

1. Franceschi, C. et al.: Inflammaging: a new immune–metabolic viewpoint for age-related diseases. In: Nature Reviews Endocrinology. 2018; Band 14, Heft 10, S. 576–590. DOI: 10.1038/s41574-018-0059-4 (accessed 21 July 2026).
2. Horvath, S.: DNA methylation age of human tissues and cell types. In: Genome Biology. 2013; Band 14, Heft 10, S. R115. DOI: 10.1186/gb-2013-14-10-r115 (accessed 21 July 2026).
3. Kennedy, B. K. et al.: Geroscience: linking aging to chronic disease. In: Cell. 2014; Band 159, Heft 4, S. 709–713. DOI: 10.1016/j.cell.2014.10.039 (accessed 21 July 2026).
4. López-Otín, C. et al.: The hallmarks of aging. In: Cell. 2013; Band 153, Heft 6, S. 1194–1217. DOI: 10.1016/j.cell.2013.05.039 (accessed 21 July 2026).
5. World Health Organization: Decade of Healthy Ageing: Baseline Report. Geneva 2020. Online: https://www.who.int/publications/i/item/9789240017900 (accessed 21 July 2026).

Self-test: sleep quality

Source: /selbsttest-schlafqualitaet

1. Caddick, Z. A. et al.: A review of the environmental parameters necessary for an optimal sleep environment. In: Building and Environment. 2018; Band 132, S. 11–20. DOI: 10.1016/j.buildenv.2018.01.020 (accessed 21 July 2026).
2. Carney, C. E. et al.: The Consensus Sleep Diary: Standardizing Prospective Sleep Self-Monitoring. In: Sleep. 2012; Band 35, Heft 2, S. 287–302. DOI: 10.5665/sleep.1642 (accessed 21 July 2026).
3. Clark, I.; Landolt, H. P.: Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials. In: Sleep Medicine Reviews. 2017; Band 31, S. 70–78. DOI: 10.1016/j.smrv.2016.01.006 (accessed 21 July 2026).
4. Costello, R. B. et al.: The effectiveness of melatonin for promoting healthy sleep: a rapid evidence assessment of the literature. In: Nutrition Journal. 2014; Band 13, S. 106. DOI: 10.1186/1475-2891-13-106 (accessed 21 July 2026).
5. Ebrahim, I. O. et al.: Alcohol and sleep I: effects on normal sleep. In: Alcoholism: Clinical and Experimental Research. 2013; Band 37, Heft 4, S. 539–549. DOI: 10.1111/acer.12006 (accessed 21 July 2026).
6. Hirshkowitz, M. et al.: National Sleep Foundation’s sleep time duration recommendations: methodology and results summary. In: Sleep Health. 2015; Band 1, Heft 1, S. 40–43. DOI: 10.1016/j.sleh.2014.12.010 (accessed 21 July 2026).
7. Irwin, M. R.: Why sleep is important for health: a psychoneuroimmunology perspective. In: Annual Review of Psychology. 2015; Band 66, S. 143–172. DOI: 10.1146/annurev-psych-010213-115205 (accessed 21 July 2026).
8. Kalmbach, D. A. et al.: The impact of stress on sleep: Pathogenic sleep reactivity as a vulnerability to insomnia and circadian disorders. In: Journal of Sleep Research. 2018; Band 27, Heft 6, S. e12710. DOI: 10.1111/jsr.12710 (accessed 21 July 2026).
9. Kredlow, M. A. et al.: The effects of physical activity on sleep: a meta-analytic review. In: Journal of Behavioral Medicine. 2015; Band 38, Heft 3, S. 427–449. DOI: 10.1007/s10865-015-9617-6 (accessed 21 July 2026).
10. Lloyd-Jones, D. M. et al.: Life’s Essential 8: Updating and Enhancing the American Heart Association’s Construct of Cardiovascular Health: A Presidential Advisory From the American Heart Association. In: Circulation. 2022; Band 146, Heft 5, S. e18–e43. DOI: 10.1161/CIR.0000000000001078 (accessed 21 July 2026).
11. Medic, G.; Wille, M.; Hemels, M. E. H.: Short- and long-term health consequences of sleep disruption. In: Nature and Science of Sleep. 2017; Band 9, S. 151–161. DOI: 10.2147/NSS.S134864 (accessed 21 July 2026).
12. Phillips, A. J. K. et al.: Irregular sleep/wake patterns are associated with poorer academic performance and delayed circadian and sleep/wake timing. In: Scientific Reports. 2017; Band 7, S. 3216. DOI: 10.1038/s41598-017-03171-4 (accessed 21 July 2026).
13. St-Onge, M. P. et al.: Sleep duration and quality: impact on lifestyle behaviors and cardiometabolic health: a scientific statement from the American Heart Association. In: Circulation. 2016; Band 134, Heft 18, S. e367–e386. DOI: 10.1161/CIR.0000000000000444 (accessed 21 July 2026).
14. Touitou, Y.; Reinberg, A.; Touitou, D.: Association between light at night, melatonin secretion, sleep deprivation, and the internal clock: Health impacts and mechanisms of circadian disruption. In: Life Sciences. 2017; Band 173, S. 94–106. DOI: 10.1016/j.lfs.2017.02.008 (accessed 21 July 2026).

Self-test: stress level

Source: /selbsttest-burnout-stresslevel

1. Aronsson, G. et al.: A systematic review including meta-analysis of work environment and burnout symptoms. In: BMC Public Health. 2017; Band 17, S. 264. DOI: 10.1186/s12889-017-4153-7 (accessed 21 July 2026).
2. Firth, J. et al.: The effects of dietary improvement on symptoms of depression and anxiety: a meta-analysis of randomized controlled trials. In: Psychosomatic Medicine. 2019; Band 81, Heft 3, S. 265–280. DOI: 10.1097/PSY.0000000000000673 (accessed 21 July 2026).
3. Maslach, C.; Leiter, M. P.: Understanding the burnout experience: recent research and its implications for psychiatry. In: World Psychiatry. 2016; Band 15, Heft 2, S. 103–111. DOI: 10.1002/wps.20311 (accessed 21 July 2026).
4. Salvagioni, D. A. J. et al.: Physical, psychological and occupational consequences of job burnout: A systematic review of prospective studies. In: PLoS ONE. 2017; Band 12, Heft 10, S. e0185781. DOI: 10.1371/journal.pone.0185781 (accessed 21 July 2026).
5. Stubbs, B. et al.: EPA guidance on physical activity as a treatment for severe mental illness: a meta-review of the evidence and Position Statement from the European Psychiatric Association (EPA). In: European Psychiatry. 2018; Band 54, S. 124–144. DOI: 10.1016/j.eurpsy.2018.07.004 (accessed 21 July 2026).
6. World Health Organization: Mental health at work. Geneva 2022. Online: https://www.who.int/news-room/fact-sheets/detail/mental-health-at-work (accessed 21 July 2026).

Self-test: gut health

Source: /selbsttest-darmgesundheit

1. Cryan, J. F. et al.: The Microbiota-Gut-Brain Axis. In: Physiological Reviews. 2019; Band 99, Heft 4, S. 1877–2013. DOI: 10.1152/physrev.00018.2018 (accessed 21 July 2026).
2. Fan, Y.; Pedersen, O.: Gut microbiota in human metabolic health and disease. In: Nature Reviews Microbiology. 2021; Band 19, Heft 1, S. 55–71. DOI: 10.1038/s41579-020-0433-9 (accessed 21 July 2026).
3. Integrative HMP (iHMP) Research Network Consortium: The Integrative Human Microbiome Project. In: Nature. 2019; Band 569, Heft 7758, S. 641–648. DOI: 10.1038/s41586-019-1238-8 (accessed 21 July 2026).
4. Mailing, L. J. et al.: Exercise and the Gut Microbiome: A Review of the Evidence, Potential Mechanisms, and Implications for Human Health. In: Exercise and Sport Sciences Reviews. 2019; Band 47, Heft 2, S. 75–85. DOI: 10.1249/JES.0000000000000183 (accessed 21 July 2026).
5. Makki, K. et al.: The Impact of Dietary Fiber on Gut Microbiota in Host Health and Disease. In: Cell Host & Microbe. 2018; Band 23, Heft 6, S. 705–715. DOI: 10.1016/j.chom.2018.05.012 (accessed 21 July 2026).
6. Valdes, A. M. et al.: Role of the gut microbiota in nutrition and health. In: BMJ. 2018; Band 361, S. k2179. DOI: 10.1136/bmj.k2179 (accessed 21 July 2026).

Self-test: cardiovascular health

Source: /selbsttest-herz-kreislauf

1. Lichtenstein, A. H. et al.: 2021 Dietary Guidance to Improve Cardiovascular Health: A Scientific Statement From the American Heart Association. In: Circulation. 2021; Band 144, Heft 23, S. e472–e487. DOI: 10.1161/CIR.0000000000001031 (accessed 21 July 2026).
2. Lloyd-Jones, D. M. et al.: Life’s Essential 8: Updating and Enhancing the American Heart Association’s Construct of Cardiovascular Health: A Presidential Advisory From the American Heart Association. In: Circulation. 2022; Band 146, Heft 5, S. e18–e43. DOI: 10.1161/CIR.0000000000001078 (accessed 21 July 2026).
3. Visseren, F. L. J. et al.: 2021 ESC Guidelines on cardiovascular disease prevention in clinical practice. In: European Heart Journal. 2021; Band 42, Heft 34, S. 3227–3337. DOI: 10.1093/eurheartj/ehab484 (accessed 21 July 2026).
4. World Health Organization: Cardiovascular diseases (CVDs). Geneva. Online: https://www.who.int/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds) (accessed 21 July 2026).
5. World Health Organization: WHO Guidelines on Physical Activity and Sedentary Behaviour. Geneva 2020. Online: https://www.who.int/publications/i/item/9789240015128 (accessed 21 July 2026).
6. Yusuf, S. et al.: Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. In: The Lancet. 2004; Band 364, Heft 9438, S. 937–952. DOI: 10.1016/S0140-6736(04)17018-9 (accessed 21 July 2026).

Self-test: longevity / biological ageing

Source: /selbsttest-longevity

1. Bell, C. G. et al.: DNA methylation aging clocks: challenges and recommendations. In: Genome Biology. 2019; Band 20, S. 249. DOI: 10.1186/s13059-019-1824-y (accessed 21 July 2026).
2. Horvath, S.: DNA methylation age of human tissues and cell types. In: Genome Biology. 2013; Band 14, Heft 10, S. R115. DOI: 10.1186/gb-2013-14-10-r115 (accessed 21 July 2026).

Self-test: Which Complete Check?

Source: /selbsttest-complete-check

1. German Society of Internal Medicine (DGIM): information and positions on prevention and preventive care in internal medicine. Wiesbaden. Online: https://www.dgim.de (accessed 21 July 2026).
2. U.S. Preventive Services Task Force (USPSTF): Recommendations for Primary Care Practice. Online: https://www.uspreventiveservicestaskforce.org/uspstf/recommendation-topics (accessed 21 July 2026).
3. Visseren, F. L. J. et al.: 2021 ESC Guidelines on cardiovascular disease prevention in clinical practice. In: European Heart Journal. 2021; Band 42, Heft 34, S. 3227–3337. DOI: 10.1093/eurheartj/ehab484 (accessed 21 July 2026).
4. World Health Organization: World Report on Ageing and Health. Geneva 2015. Online: https://www.who.int/publications/i/item/9789241565042 (accessed 21 July 2026).

Note

Citing studies and guidelines does not imply a recommendation of any particular product or a promise of treatment success. Whether a method is suitable in your case is decided solely by the treating doctor after a personal examination.

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