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Every study cited on the site, page by page. Each link leads to the PubMed record, the DOI or the official report.

Fasting

What does the pancreas do after a meal or during a fast?

  1. Cahill, "Fuel metabolism in starvation", Annual Review of Nutrition, 2006 pubmed.ncbi.nlm.nih.gov
  2. Cheng et al., "Fasting-Mimicking Diet Promotes Ngn3-Driven β-Cell Regeneration to Reverse Diabetes", Cell, 2017 pubmed.ncbi.nlm.nih.gov
  3. International Diabetes Federation, "Guideline for management of postmeal glucose in diabetes", 2011 www.idf.org

What happens in the body during a fast?

  1. Cahill, "Fuel metabolism in starvation", Annual Review of Nutrition, 2006 pubmed.ncbi.nlm.nih.gov
  2. Ho et al., "Fasting enhances growth hormone secretion…", J Clin Invest, 1988 www.jci.org
  3. Da Silva Xavier, "The Cells of the Islets of Langerhans", J Clin Med, 2018 pmc.ncbi.nlm.nih.gov
  4. Butler et al., "β-cell deficit… in humans with type 2 diabetes", Diabetes, 2003 pubmed.ncbi.nlm.nih.gov
  5. Luiking et al., motilin and gallbladder emptying while fasting, Gut, 1998 pubmed.ncbi.nlm.nih.gov
  6. Dawson and Karpen, "Intestinal transport and metabolism of bile acids", J Lipid Res, 2015 pmc.ncbi.nlm.nih.gov
  7. Chevrier et al., weight loss and pollutants in the blood, Int J Obes, 2000 doi.org
  8. Mehanna et al., "Refeeding syndrome", BMJ, 2008 pmc.ncbi.nlm.nih.gov

What happens hour by hour when you fast?

  1. Cahill, "Fuel metabolism in starvation", Annual Review of Nutrition, 2006 pubmed.ncbi.nlm.nih.gov
  2. Ho et al., "Fasting enhances growth hormone secretion and amplifies the complex rhythms of growth hormone secretion in man", Journal of Clinical Investigation, 1988 pubmed.ncbi.nlm.nih.gov
  3. Anton et al., "Flipping the metabolic switch: understanding and applying the health benefits of fasting", Obesity, 2018 pubmed.ncbi.nlm.nih.gov
  4. de Cabo and Mattson, "Effects of intermittent fasting on health, aging, and disease", New England Journal of Medicine, 2019 pubmed.ncbi.nlm.nih.gov
  5. Alirezaei et al., "Short-term fasting induces profound neuronal autophagy", Autophagy, 2010 pubmed.ncbi.nlm.nih.gov

An ordinary day

What time does the body make its hormones?

  1. Monk, "The post-lunch dip in performance", Clinics in Sports Medicine, 2005 pubmed.ncbi.nlm.nih.gov
  2. Scheer, Morris and Shea, "The internal circadian clock increases hunger and appetite in the evening independent of food intake and other behaviors", Obesity, 2013 pubmed.ncbi.nlm.nih.gov
  3. Fries, Dettenborn and Kirschbaum, "The cortisol awakening response (CAR): facts and future directions", Int J Psychophysiol, 2009 pubmed.ncbi.nlm.nih.gov
  4. Lewy et al., article on the evening onset of melatonin secretion (DLMO), 1999 pubmed.ncbi.nlm.nih.gov
  5. Van Cauter et al., "Age-related changes in slow wave sleep and REM sleep and relationship with growth hormone and cortisol levels in healthy men", JAMA, 2000 jamanetwork.com
  6. Burgess et al., "Preliminary evidence that the dim light melatonin onset predicts the timing of sleep", Behav Sleep Med, 2003 pubmed.ncbi.nlm.nih.gov

What happens in the body during sleep?

  1. Patel et al., "Physiology, Sleep Stages", StatPearls, NCBI www.ncbi.nlm.nih.gov
  2. Van Cauter et al., "Age-related changes in slow wave sleep and REM sleep and relationship with growth hormone and cortisol levels in healthy men", JAMA, 2000 jamanetwork.com
  3. Leproult and Van Cauter, "Effect of 1 week of sleep restriction on testosterone levels in young healthy men", JAMA, 2011 pubmed.ncbi.nlm.nih.gov

What happens in the body after a meal?

  1. International Diabetes Federation, "Guideline for management of postmeal glucose in diabetes", 2011 www.idf.org
  2. Cummings et al., "A preprandial rise in plasma ghrelin levels suggests a role in meal initiation in humans", Diabetes, 2001 pubmed.ncbi.nlm.nih.gov
  3. Holst, "The physiology of glucagon-like peptide 1", Physiol Rev, 2007 pubmed.ncbi.nlm.nih.gov

How long does caffeine stay in the body?

  1. Marcus et al., "Acute Effects of Coffee Consumption on Health among Ambulatory Adults", N Engl J Med 388:1092-1100, 2023 doi.org
  2. Kim et al., "Coffee Consumption and Incident Tachyarrhythmias", JAMA Intern Med 181(9):1185-1193, 2021 doi.org
  3. Fredholm et al., "Actions of caffeine in the brain with special reference to factors that contribute to its widespread use", Pharmacol Rev 51(1):83-133, 1999 pharmrev.aspetjournals.org
  4. Institute of Medicine, "Caffeine for the Sustainment of Mental Task Performance", chapter Pharmacology of Caffeine, 2001 www.ncbi.nlm.nih.gov
  5. Drake et al., "Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed", J Clin Sleep Med, 2013 pubmed.ncbi.nlm.nih.gov
  6. Robertson et al., "Effects of caffeine on plasma renin activity, catecholamines and blood pressure", N Engl J Med, 1978 pubmed.ncbi.nlm.nih.gov
  7. Robertson et al., "Tolerance to the humoral and hemodynamic effects of caffeine in man", J Clin Invest, 1981 pubmed.ncbi.nlm.nih.gov
  8. Lovallo et al., "Caffeine stimulation of cortisol secretion across the waking hours in relation to caffeine intake levels", Psychosom Med, 2005 pubmed.ncbi.nlm.nih.gov

Why do you sleep badly after drinking alcohol?

  1. Jones, "Evidence-based survey of the elimination rates of ethanol from blood with applications in forensic casework", Forensic Sci Int, 2010 pubmed.ncbi.nlm.nih.gov
  2. Ebrahim et al., "Alcohol and sleep I: effects on normal sleep", Alcohol Clin Exp Res, 2013 pubmed.ncbi.nlm.nih.gov
  3. Mitchell, Teigen and Ramchandani, "Absorption and peak blood alcohol concentration after drinking beer, wine, or spirits", Alcohol Clin Exp Res, 2014 pmc.ncbi.nlm.nih.gov

Where do the fats we eat go?

  1. Bach AC, Babayan VK. Medium-chain triglycerides: an update. Am J Clin Nutr. 1982;36(5):950-62 pubmed.ncbi.nlm.nih.gov
  2. Mu H, Høy CE. The digestion of dietary triacylglycerols. Prog Lipid Res. 2004;43(2):105-33 pubmed.ncbi.nlm.nih.gov
  3. Calder PC. Very long-chain n-3 fatty acids and human health: fact, fiction and the future. Proc Nutr Soc. 2018;77(1):52-72 pubmed.ncbi.nlm.nih.gov
  4. Mu H, Høy CE. Effects of different medium-chain fatty acids on intestinal absorption of structured triacylglycerols. Lipids. 2000;35(1):83-9 pubmed.ncbi.nlm.nih.gov
  5. Mumme K, Stonehouse W. Effects of medium-chain triglycerides on weight loss and body composition: a meta-analysis of randomized controlled trials. J Acad Nutr Diet. 2015;115(2):249-63 doi.org
  6. Mihas C, et al. Diagnostic value of postprandial triglyceride testing in healthy subjects: a meta-analysis. Curr Vasc Pharmacol. 2011;9(3):271-80 doi.org

Exercise and stress

What happens in the body during and after exercise?

  1. Zouhal et al., "Catecholamines and the effects of exercise, training and gender", Sports Med, 2008 pubmed.ncbi.nlm.nih.gov
  2. Hill et al., "Exercise and circulating cortisol levels: the intensity threshold effect", J Endocrinol Invest, 2008 pubmed.ncbi.nlm.nih.gov
  3. Brooks, "The Science and Translation of Lactate Shuttle Theory", Cell Metabolism, 2018 doi.org
  4. Phillips et al., "Mixed muscle protein synthesis and breakdown after resistance exercise in humans", Am J Physiol, 1997 pubmed.ncbi.nlm.nih.gov
  5. Burke, van Loon and Hawley, "Postexercise muscle glycogen resynthesis in humans", J Appl Physiol, 2017 doi.org
  6. Cheung et al., "Delayed onset muscle soreness: treatment strategies and performance factors", Sports Med, 2003 pubmed.ncbi.nlm.nih.gov
  7. Menzies et al., "Blood lactate clearance during active recovery after an intense running bout depends on the intensity of the active recovery", J Sports Sci, 2010 doi.org

What happens in the body when you are stressed?

  1. Dickerson and Kemeny, "Acute stressors and cortisol responses: a theoretical integration and synthesis of laboratory research", Psychol Bull, 2004 pubmed.ncbi.nlm.nih.gov
  2. Zaccaro et al., "How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing", Front Hum Neurosci, 2018 pubmed.ncbi.nlm.nih.gov

Do gelatin or collagen help repair tendons?

  1. Shaw et al., "Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis", Am J Clin Nutr, 2017 pubmed.ncbi.nlm.nih.gov
  2. Rio et al., "Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy", Br J Sports Med, 2015 pubmed.ncbi.nlm.nih.gov
  3. Paxton et al., "Optimizing an intermittent stretch paradigm using ERK1/2 phosphorylation results in increased collagen synthesis in engineered ligaments", Tissue Eng Part A, 2012 pubmed.ncbi.nlm.nih.gov
  4. Miller et al., "Coordinated collagen and muscle protein synthesis in human patella tendon and quadriceps muscle after exercise", J Physiol, 2005 pubmed.ncbi.nlm.nih.gov
  5. Magnusson, Langberg and Kjaer, "The pathogenesis of tendinopathy: balancing the response to loading", Nat Rev Rheumatol, 2010 pubmed.ncbi.nlm.nih.gov
  6. Bohm, Mersmann and Arampatzis, "Human tendon adaptation in response to mechanical loading", Sports Med Open, 2015 pubmed.ncbi.nlm.nih.gov
  7. Kubo et al., "Effects of isometric training on the elasticity of human tendon structures in vivo", J Appl Physiol 91:26-32, 2001 pubmed.ncbi.nlm.nih.gov
  8. Heinemeier et al., "Lack of tissue renewal in human adult Achilles tendon is revealed by nuclear bomb 14C", FASEB J, 2013 pubmed.ncbi.nlm.nih.gov
  9. Lis and Baar, "Effects of different vitamin C-enriched collagen derivatives on collagen synthesis", Int J Sport Nutr Exerc Metab, 2019 pubmed.ncbi.nlm.nih.gov
  10. Praet et al., "Oral supplementation of specific collagen peptides combined with calf-strengthening exercises enhances function and reduces pain in Achilles tendinopathy patients", Nutrients, 2019 doi.org
  11. Sharma and Maffulli, "Tendon injury and tendinopathy: healing and repair", J Bone Joint Surg Am, 2005 pubmed.ncbi.nlm.nih.gov

How many reps should you do in strength training?

  1. Nuzzo et al., "Maximal Number of Repetitions at Percentages of the One Repetition Maximum: A Meta-Regression and Moderator Analysis of Sex, Age, Training Status, and Exercise", Sports Med 54:303-321, 2024 pmc.ncbi.nlm.nih.gov
  2. Schoenfeld et al., "Loading Recommendations for Muscle Strength, Hypertrophy, and Local Endurance: A Re-Examination of the Repetition Continuum", Sports 9(2):32, 2021 www.ncbi.nlm.nih.gov
  3. Morton et al., "Neither load nor systemic hormones determine resistance training-mediated hypertrophy or strength gains in resistance-trained young men", J Appl Physiol 121:129-138, 2016 www.ncbi.nlm.nih.gov
  4. Schoenfeld et al., "Strength and Hypertrophy Adaptations Between Low- vs. High-Load Resistance Training: A Systematic Review and Meta-analysis", J Strength Cond Res 31(12):3508-3523, 2017 pubmed.ncbi.nlm.nih.gov
  5. Campos et al., "Muscular adaptations in response to three different resistance-training regimens: specificity of repetition maximum training zones", Eur J Appl Physiol 88:50-60, 2002 pubmed.ncbi.nlm.nih.gov
  6. Refalo et al., "Influence of Resistance Training Proximity-to-Failure on Skeletal Muscle Hypertrophy: A Systematic Review with Meta-analysis", Sports Med 53:649-665, 2023 pubmed.ncbi.nlm.nih.gov
  7. Robinson et al., "Exploring the Dose-Response Relationship Between Estimated Resistance Training Proximity to Failure, Strength Gain, and Muscle Hypertrophy: A Series of Meta-Regressions", Sports Med 54(9):2209-2231, 2024 pubmed.ncbi.nlm.nih.gov
  8. Burd et al., "Low-load high volume resistance exercise stimulates muscle protein synthesis more than high-load low volume resistance exercise in young men", PLoS One 5(8):e12033, 2010 pmc.ncbi.nlm.nih.gov
  9. Damas et al., "Resistance training-induced changes in integrated myofibrillar protein synthesis are related to hypertrophy only after attenuation of muscle damage", J Physiol 594(18):5209-5222, 2016 pubmed.ncbi.nlm.nih.gov
  10. Schoenfeld, Ogborn and Krieger, "Dose-response relationship between weekly resistance training volume and increases in muscle mass", J Sports Sci 35(11):1073-1082, 2017 pubmed.ncbi.nlm.nih.gov
  11. Morán-Navarro et al., "Time course of recovery following resistance training leading or not to failure", Eur J Appl Physiol, 2017 pubmed.ncbi.nlm.nih.gov

What do the adrenal glands do?

  1. Dickerson SS, Kemeny ME. Acute stressors and cortisol responses: a theoretical integration and synthesis of laboratory research. Psychol Bull. 2004;130(3):355-91 pubmed.ncbi.nlm.nih.gov
  2. Fries E, Dettenborn L, Kirschbaum C. The cortisol awakening response (CAR): facts and future directions. Int J Psychophysiol. 2009;72(1):67-73 pubmed.ncbi.nlm.nih.gov
  3. Dutt M, Wehrle CJ, Jialal I. Physiology, Adrenal Gland. StatPearls. 2023 pubmed.ncbi.nlm.nih.gov
  4. Lam J, et al. Anatomy, Abdomen and Pelvis: Adrenal Glands. StatPearls. 2022 www.ncbi.nlm.nih.gov
  5. Cadegiani FA, Kater CE. Adrenal fatigue does not exist: a systematic review. BMC Endocr Disord. 2016;16(1):48 doi.org
  6. Adam EK, et al. Diurnal cortisol slopes and mental and physical health outcomes: a systematic review and meta-analysis. Psychoneuroendocrinology. 2017;83:25-41 pmc.ncbi.nlm.nih.gov

How do you stimulate the vagus nerve?

  1. Laborde S et al. Effects of voluntary slow breathing on heart rate and heart rate variability: A systematic review and a meta-analysis. Neurosci Biobehav Rev. 2022;138:104711 doi.org
  2. Jose AD, Taylor RR. Autonomic blockade by propranolol and atropine to study intrinsic myocardial function in man. J Clin Invest. 1969;48(11):2019-31 doi.org
  3. Wolf V et al. Does transcutaneous auricular vagus nerve stimulation affect vagally mediated heart rate variability? A living and interactive Bayesian meta-analysis. Psychophysiology. 2021;58(11):e13933 doi.org
  4. Koopman FA et al. Vagus nerve stimulation inhibits cytokine production and attenuates disease severity in rheumatoid arthritis. Proc Natl Acad Sci U S A. 2016;113(29):8284-9 doi.org
  5. Taylor IL, Feldman M. Effect of cephalic-vagal stimulation on insulin, gastric inhibitory polypeptide, and pancreatic polypeptide release in humans. J Clin Endocrinol Metab. 1982;55(6):1114-7 doi.org
  6. Garg P et al. Effect of breathing exercises on blood pressure and heart rate: A systematic review and meta-analysis. Int J Cardiol Cardiovasc Risk Prev. 2024;20:200232 doi.org
  7. Meehan ZM, Shaffer F. Do longer exhalations increase HRV during slow-paced breathing?. Appl Psychophysiol Biofeedback. 2024;49(3):407-417 doi.org
  8. Ma X et al. The effect of diaphragmatic breathing on attention, negative affect and stress in healthy adults. Front Psychol. 2017;8:874 doi.org
  9. Caspers C et al. Diving reflex: can the time course of heart rate reduction be quantified?. Scand J Med Sci Sports. 2011;21(1):18-31 doi.org
  10. Foley JO, DuBois FS. Quantitative studies of the vagus nerve in the cat. I. The ratio of sensory to motor fibers. J Comp Neurol. 1937;67(1):49-67 doi.org

What happens in the body during breath holding?

  1. Lindholm P, Lundgren CE. Alveolar gas composition before and after maximal breath-holds in competitive divers. Undersea Hyperb Med. 2006;33(6):463-7 pubmed.ncbi.nlm.nih.gov
  2. Lindholm P. Loss of motor control and/or loss of consciousness during breath-hold competitions. Int J Sports Med. 2007;28(4):295-9 doi.org
  3. Baković D et al. Spleen volume and blood flow response to repeated breath-hold apneas. J Appl Physiol. 2003;95(4):1460-6 doi.org
  4. Dujic Z et al. Involuntary breathing movements improve cerebral oxygenation during apnea struggle phase in elite divers. J Appl Physiol. 2009;107(6):1840-6 doi.org
  5. Mulder E et al. Unlocking the depths: multiple factors contribute to risk for hypoxic blackout during deep freediving. Eur J Appl Physiol. 2023;123(11):2483-93 doi.org
  6. Bosco G et al. Arterial blood gas analysis in breath-hold divers at depth. Front Physiol. 2018;9:1558 doi.org

How does lymph flow without a heart to pump it?

  1. Moore JE Jr, Bertram CD. Lymphatic system flows. Annu Rev Fluid Mech. 2018;50:459-82 pubmed.ncbi.nlm.nih.gov
  2. Olszewski WL, Engeset A. Intrinsic contractility of prenodal lymph vessels and lymph flow in human leg. Am J Physiol. 1980;239(6):H775-83 pubmed.ncbi.nlm.nih.gov
  3. Swartz MA. The physiology of the lymphatic system. Adv Drug Deliv Rev. 2001;50(1-2):3-20 pubmed.ncbi.nlm.nih.gov
  4. Havas E et al. Lymph flow dynamics in exercising human skeletal muscle as detected by scintography. J Physiol. 1997;504(Pt 1):233-9 doi.org
  5. Schmitz KH et al. Weight lifting in women with breast-cancer-related lymphedema. N Engl J Med. 2009;361(7):664-73 doi.org
  6. Lattuada M et al. Abdominal lymph flow in an endotoxin sepsis model: influence of spontaneous breathing and mechanical ventilation. Crit Care Med. 2006;34(11):2792-8 doi.org
  7. Tan IC et al. Assessment of lymphatic contractile function after manual lymphatic drainage using near-infrared fluorescence imaging. Arch Phys Med Rehabil. 2011;92(5):756-764.e1 doi.org
  8. Hinton LR et al. The effect of respiration and body position on terminal thoracic duct diameter and the lymphovenous junction: an exploratory ultrasound study. Clin Anat. 2022;35(4):447-453 doi.org
  9. Moazzam S et al. The physiology of thoracic duct pressure and flow: a review of the literature. Physiol Rep. 2026;14(2):e70742 doi.org

Sex hormones

How do hormones change during the menstrual cycle?

  1. StatPearls, "Physiology, Ovulation And Basal Body Temperature", NCBI www.statpearls.com
  2. Tucker et al., "The Effect of the Menstrual Cycle on Energy Intake: A Systematic Review and Meta-analysis", Nutrition Reviews, 2025 www.ncbi.nlm.nih.gov
  3. Reed and Carr, "The Normal Menstrual Cycle and the Control of Ovulation", Endotext, NCBI www.ncbi.nlm.nih.gov
  4. Bull et al., "Real-world menstrual cycle characteristics of more than 600,000 menstrual cycles", npj Digital Medicine, 2019 pmc.ncbi.nlm.nih.gov
  5. Wilcox et al., "Timing of sexual intercourse in relation to ovulation", N Engl J Med, 1995 pubmed.ncbi.nlm.nih.gov

How do hormones change during pregnancy?

  1. Wilcox, Baird and Weinberg, "Time of implantation of the conceptus and loss of pregnancy", New England Journal of Medicine, 1999 pubmed.ncbi.nlm.nih.gov
  2. Cole, "Biological functions of hCG and hCG-related molecules", Reprod Biol Endocrinol, 2010 pmc.ncbi.nlm.nih.gov
  3. Csapo et al., "The significance of the human corpus luteum in pregnancy maintenance", Am J Obstet Gynecol, 1972 pubmed.ncbi.nlm.nih.gov
  4. Nana and Williamson, "Pituitary and Adrenal Disorders of Pregnancy", Endotext, NCBI www.ncbi.nlm.nih.gov
  5. Barnhart et al., "Symptomatic patients with an early viable intrauterine pregnancy: hCG curves redefined", Obstet Gynecol, 2004 pubmed.ncbi.nlm.nih.gov
  6. Lee and Saha, "Nausea and vomiting of pregnancy", Gastroenterol Clin North Am, 2011 pmc.ncbi.nlm.nih.gov
  7. de Haas et al., "Physiological adaptation of maternal plasma volume during pregnancy: a systematic review and meta-analysis", Ultrasound Obstet Gynecol, 2017 doi.org

Which hormones change at menopause?

  1. McKinlay, Brambilla and Posner, "The normal menopause transition", Maturitas, 1992 pubmed.ncbi.nlm.nih.gov
  2. NICE, "Menopause: identification and management" (NG23), 2015 www.nice.org.uk
  3. Randolph et al., "Change in follicle-stimulating hormone and estradiol across the menopausal transition", JCEM, 2011 (SWAN study) pmc.ncbi.nlm.nih.gov
  4. Avis et al., "Duration of menopausal vasomotor symptoms over the menopause transition", JAMA Intern Med, 2015 (SWAN study) pubmed.ncbi.nlm.nih.gov
  5. Do et al., "Predictors of age at natural menopause", Ann Hum Biol, 1998 pubmed.ncbi.nlm.nih.gov

Which hormones are released after ejaculation?

  1. Bohlen et al., "Heart rate, rate-pressure product, and oxygen uptake during four sexual activities", Archives of Internal Medicine, 1984 pubmed.ncbi.nlm.nih.gov
  2. Krüger et al., "Specificity of the neuroendocrine response to orgasm during sexual arousal in men", J Endocrinol, 2003 pubmed.ncbi.nlm.nih.gov
  3. Krüger et al., "Orgasm-induced prolactin secretion: feedback control of sexual drive?", Neurosci Biobehav Rev, 2002 pubmed.ncbi.nlm.nih.gov
  4. Krüger et al., "Neuroendocrine and cardiovascular response to sexual arousal and orgasm in men", Psychoneuroendocrinology, 1998 pubmed.ncbi.nlm.nih.gov

When is testosterone highest?

  1. Bhasin et al., "Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline", Journal of Clinical Endocrinology and Metabolism, 2018 pubmed.ncbi.nlm.nih.gov
  2. Brambilla et al., "The effect of diurnal variation on clinical measurement of serum testosterone and other sex hormone levels in men", JCEM, 2009 pubmed.ncbi.nlm.nih.gov
  3. Leproult and Van Cauter, "Effect of 1 week of sleep restriction on testosterone levels in young healthy men", JAMA, 2011 pubmed.ncbi.nlm.nih.gov
  4. Harman et al., "Longitudinal effects of aging on serum total and free testosterone levels in healthy men", JCEM, 2001 pubmed.ncbi.nlm.nih.gov
  5. Kuiri-Hänninen, Sankilampi and Dunkel, "Activation of the hypothalamic-pituitary-gonadal axis in infancy: minipuberty", Horm Res Paediatr, 2014 doi.org
  6. Handelsman, Hirschberg and Bermon, "Circulating Testosterone as the Hormonal Basis of Sex Differences in Athletic Performance", Endocr Rev, 2018 pubmed.ncbi.nlm.nih.gov

The brain

How do neurons communicate with each other?

  1. PubMed pubmed.ncbi.nlm.nih.gov
  2. PubMed pubmed.ncbi.nlm.nih.gov

Bones, kidneys and sun

How long in the sun to make vitamin D?

  1. Webb AR, Kline L, Holick MF. Influence of season and latitude on the cutaneous synthesis of vitamin D3. J Clin Endocrinol Metab. 1988;67(2):373-8 pubmed.ncbi.nlm.nih.gov
  2. Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357(3):266-81 pubmed.ncbi.nlm.nih.gov
  3. Madronich S. Analytic formula for the clear-sky UV index. Photochem Photobiol. 2007;83(6):1537-8 pubmed.ncbi.nlm.nih.gov
  4. EFSA NDA Panel. Dietary reference values for vitamin D. EFSA Journal. 2016;14(10):4547 doi.org
  5. Neale RE, et al. The effect of sunscreen on vitamin D: a review. Br J Dermatol. 2019;181(5):907-15 doi.org

Why do bones become fragile with age?

  1. Compston JE, McClung MR, Leslie WD. Osteoporosis. Lancet. 2019;393(10169):364-76 pubmed.ncbi.nlm.nih.gov
  2. Weaver CM, et al. The National Osteoporosis Foundation's position statement on peak bone mass development and lifestyle factors. Osteoporos Int. 2016;27(4):1281-386 pubmed.ncbi.nlm.nih.gov
  3. Greendale GA, et al. Bone mineral density loss in relation to the final menstrual period in a multiethnic cohort (SWAN). J Bone Miner Res. 2012;27(1):111-8 pubmed.ncbi.nlm.nih.gov
  4. Charles JF, Aliprantis AO. Osteoclasts: more than 'bone eaters'. Trends Mol Med. 2014;20(8):449-59 pmc.ncbi.nlm.nih.gov
  5. Daponte V, et al. Current perspectives on the multiple roles of osteoclasts: mechanisms of osteoclast-osteoblast communication and potential clinical implications. eLife. 2024;13:RP95083 doi.org

How does a kidney stone form, and does it pass on its own?

  1. Scales CD Jr, Smith AC, Hanley JM, Saigal CS. Prevalence of kidney stones in the United States. Eur Urol. 2012;62(1):160-5 pubmed.ncbi.nlm.nih.gov
  2. Coll DM, Varanelli MJ, Smith RC. Relationship of spontaneous passage of ureteral calculi to stone size and location as revealed by unenhanced helical CT. AJR Am J Roentgenol. 2002;178(1):101-3 pubmed.ncbi.nlm.nih.gov
  3. Borghi L, et al. Urinary volume, water and recurrences in idiopathic calcium nephrolithiasis: a 5-year randomized prospective study. J Urol. 1996;155(3):839-43 pubmed.ncbi.nlm.nih.gov
  4. Tasian GE, et al. Daily mean temperature and clinical kidney stone presentation in five U.S. metropolitan areas: a time-series analysis. Environ Health Perspect. 2014;122(10):1081-7 pubmed.ncbi.nlm.nih.gov
  5. Borghi L, et al. Comparison of two diets for the prevention of recurrent stones in idiopathic hypercalciuria. N Engl J Med. 2002;346(2):77-84 pubmed.ncbi.nlm.nih.gov