The science is real. Here are the details.

Your chronotype is your genetically influenced preference for when you sleep, wake, and feel most alert. It's governed by clock genes — particularly PER and CRY — that regulate your internal 24-hour cycle. A 2016 genome-wide association study (Hu et al., Annals of Neurology) identified 15 gene loci linked to morningness, and Kalmbach et al. (2017, Sleep Medicine Reviews) demonstrated that chronotype predicts peak cognitive performance, hormone timing, and mood patterns throughout the day. In short, your chronotype is the genetic blueprint for when your body works best.

The four-chronotype model (Lion, Bear, Wolf, Dolphin) was developed by Dr. Michael Breus, building on decades of morningness-eveningness research that began with Horne and Östberg in 1976. The Morningness-Eveningness Questionnaire (MEQ) is the most widely validated instrument in chronobiology — cited in over 3,000 studies. While the original MEQ uses a continuous scale, the four-type classification maps to distinct clusters observed in population studies and captures the full spectrum from strong morning types to individuals with fragmented sleep patterns.

No. We are an independent product and are not affiliated with, endorsed by, or sponsored by Dr. Michael Breus or The Sleep Doctor. Our assessment is built on the publicly published morningness-eveningness research — the Horne-Östberg Morningness-Eveningness Questionnaire (MEQ) and the broader chronobiology literature it comes from — and all of our quiz questions, chronotype descriptions, schedules, and recommendations are our own original work. We credit Dr. Breus for popularizing the four-type framing referenced elsewhere on this page.

Your core chronotype is approximately 50% heritable and remains relatively stable throughout adult life. However, age-related shifts are well documented. Roenneberg et al. (2004, Current Biology) showed that adolescents and young adults shift toward later chronotypes ("night owls"), peaking around age 20, then gradually shift earlier across the lifespan. External factors like light exposure, shift work, and travel can temporarily override your chronotype, but your baseline preference tends to reassert itself when those pressures are removed.

Every human has a circadian rhythm — a roughly 24-hour biological cycle governed by the suprachiasmatic nucleus (SCN) in the hypothalamus, synchronized by light input from the retina. Your chronotype is your individual position within that cycle. Think of circadian rhythm as the universal clock mechanism, and chronotype as your personal timezone setting within it. Two people have the same circadian machinery, but a Lion's cortisol peaks 2-3 hours before a Wolf's.

Your Body Clock Code is a personalized daily timing schedule built from your chronotype, lifestyle inputs, and health goals. It covers optimal sleep and wake windows, meal timing aligned to your metabolic rhythms, peak exercise windows matched to your core body temperature curve, cognitive performance windows for focused work, supplement timing based on absorption and hormone cycles, and organ clock alignment showing which body systems are most active at each hour.

The quiz is based on validated morningness-eveningness assessment measures. Research by Kantermann et al. (2015, Chronobiology International) demonstrated that self-reported chronotype from questionnaires correlates with dim-light melatonin onset (DLMO) — the gold-standard biomarker for circadian phase measured in sleep laboratories. The quiz captures your natural sleep timing, energy patterns, and alertness preferences to classify your chronotype with high reliability.

Most people notice improved sleep quality within 3-7 days of consistently following their chronotype-aligned schedule. Burgess and Eastman (2006, Journal of Biological Rhythms) showed that systematic phase-shifting protocols — moving sleep, light exposure, and meals to circadian-optimal times — produce measurable changes in melatonin onset within one week. Full adaptation of energy patterns, digestion, and exercise performance typically takes 2-4 weeks of consistent timing.

Your digestive system follows a circadian clock independent of when you choose to eat. Sutton et al. (2018, Cell Metabolism) demonstrated that early time-restricted eating — consuming meals aligned with your body's daytime metabolic peak — reduced insulin resistance and blood pressure even without calorie changes. Jamshed et al. (2019, Obesity) confirmed that front-loading calories to the morning improves glucose tolerance and reduces appetite hormones. The takeaway: the same meal has different metabolic effects depending on when you eat it.

Yes — and the evidence is strong. Muscle strength, power output, and reaction time peak in the late afternoon when core body temperature reaches its daily high. Racinais et al. (2010, Scandinavian Journal of Medicine & Science in Sports) documented performance variations of 5-10% across the day. A comprehensive meta-analysis by Chtourou and Souissi (2012, Sports Medicine) confirmed that VO2max, anaerobic capacity, and flexibility all follow circadian patterns. This doesn't mean you should only train in the afternoon — it means matching your training intensity to your body's readiness window produces better results.

The organ clock is a timing framework — a proprietary blend of circadian science and empirical timing — supported by modern molecular biology. Zhang et al. (2014, PNAS) published a circadian transcriptome atlas showing that nearly half of all protein-coding genes follow circadian expression patterns, with each organ system peaking at specific times. Cortisol peaks early morning, testosterone around 8 AM, liver detoxification enzymes peak overnight, and growth hormone surges in early deep sleep. Your Body Clock Code maps these peaks to actionable timing recommendations.

Coach Pro gives you a protocol generator that builds chronotype-specific timing plans for each client. After a client completes their chronotype assessment, you can generate evidence-based schedules covering training windows, nutrition timing, recovery protocols, and supplement stacks — all personalized to their biology. You can track client adherence and adjust protocols as needed.

Circadian coaching is a differentiation most competitors cannot match. When clients see measurable improvements — better sleep quality scores, faster recovery, stronger performance at their peak times — they stay longer and refer others. Coaches using chronotype-based programming report higher client satisfaction because the protocols have a clear scientific rationale clients can understand and verify.

Every timing recommendation in a generated protocol is grounded in peer-reviewed research. When a client asks "why am I training at 5 PM instead of 6 AM?" you can point to the specific circadian performance data. This builds trust and positions you as a science-driven practitioner — not someone following generic templates.

Coach Pro is $79 per month, and you can start with a 14-day free trial. Cancel anytime from your dashboard settings — no contracts, no cancellation fees.

Take the free chronotype quiz. It takes about 2 minutes and gives you your chronotype result immediately — no account required, no email gate. You'll get a summary of your chronotype traits and peak timing windows right away.

Yes, anytime. Your most recent results are always available in your account. If your sleep patterns or lifestyle have changed significantly, retaking the quiz can refine your timing recommendations.