The Power of When: Discover Your Chronotype--and the Best Time to Eat Lunch, Ask for a Raise, Have Sex, Write a Novel, Take Your Meds, and More

As a chronic insomniac, I was excited to read something that might offer new solutions. So I took the test and came out as a Dolphin, which seemed a perfect fit at first, since I am high strung and stay up at nights ruminating. But when I read further, lots of the what he said about dolphin didn't fit at all. I love to eat, for example (I've never forgotten a meal in my life, and sure wish I had that wiry thin body he talked about!). And far from getting a burst of evening energy, I generally feel so exhausted after 8pm I can barely string words together. So I seem to be hungry like a bear, high-strung like a dolphin, and rise early like a lion. What the heck am I? A Dol-bear-ion?I had hoped buying the book would clear up for me what type I am, but it only further confounded me. And the advice for each type is wildly conflicting. Should I exercise in the morning like a Dolphin, or save it for afternoon, like a Lion, to give me more evening pep? Should I force myself to stay up till midnight (which would probably make me ill, is my guess), or go to bed with the sun? The advice conflicts so much that it only works if you fit neatly into one group or another.This book clearly seems to be working for lots of people, but I'd recommend taking the online quiz before you buy it, and then reading through the descriptions of each of the types, first. If you find yourself to be a hybrid like me, you might as well skip the purchase and save your money.EDITED TO ADD:After finishing the book, there are a few pieces of advice that apply to any chronotype, that I wanted to share for those who feel, like me, that they don't fit into a specific type:The first is to delay coffee until a couple of hours after awakening. According to the author, drinking caffeine immediately upon waking is a waste. For all types it's better to wait until you get an energy lull closer to mid-morning. On the other hand, no type should drink caffeine within eight hours of wanting to go to sleep, so don't wait too long. And limit yourself to one or two cups a day.Second, no type should sleep in on the weekends. He's very firm about this. For all types, it's better to lose a bit of sleep on the weekends (if you're staying out late and socializing) then to sleep in and wind up with "social jetlag" which will throw off your entire week. The most anyone should sleep in is an extra 30-45 minutes.Finally, for all types, use sunshine, exercise, protein, and cold showers when you want to wake yourself up or give yourself some extra pep. Then use warm baths, meditation, stretching, and carbs when you want the opposite, to be winding down and preparing for sleep. So, if you have trouble waking up in the morning, start out with some push ups (or whatever) followed by a cold shower, a walk outside, and a plate of eggs. If you get tired too early in the evenings and want to be able to stay up later, then use those things in the late afternoon. Conversely, if you are too alert in the evenings and have trouble falling asleep, then eat some carbs, stretch, meditate, and have a warm bath at or after dinner time.That advice all seems pretty sound to me and it's the advice I'm taking from the book and applying, despite feeling like I don't fit neatly into a chronotype. He also has a chapter on adjusting to jet lag that some might find helpful.Good luck everyone!

I participated in the survey and received Dr. Breus' feedback and suggestions as a part of a consultation to a corporate client. I reviewed his book in relation to that feedback. The criticism I offer is largely based on the limitations of the survey and the tightly defined criteria in the categories--dolphin, lion, wolf, bear. Like another reviewer, the issue arises when you are not squarely within one of his categories and a hybrid of two or more. As a psychologist I'd expect Dr. Breus would at least qualify that these categories are handy, but not definitive, and that respondents will likely fall along a continuum that may straddle categories or include traits from multiple categories. In my case, I found Dr. Breus' summary of my category based on the survey result was substantially incorrect (at least half of the characteristics he attributed were not accurate), and objectively contrary to the answers actually given in the survey. In reading the summary description of categories in the book, it is clearly not close. This problem arises, aside from failure to address the categories in terms of a continuum and instead shoehorn participants into one discreet classification, from what I think are two problems with the survey itself. First, it presents a number of questions as binary "this or that" without clarifying what constitutes a "best response". As an example, there is a question about whether, when you have an appointment or event scheduled for the morning, you set your alarm, set multiple alarms, or naturally awaken at the appropriate time. I in fact naturally awaken at the appropriate time--I'm one of those people for whom the ability to do so is "uncanny". However, as a responsible person I also set my alarm as a failsafe. I'm not saying the question or methodology is necessarily flawed, because we're not sure what he's really attempting to get at since his approach goes beyond sleep habits and extends into the realm of personality traits and behavior. The question, however, leaves the door open to ambiguous response which is the thrust of my criticism. There are numbers of questions like this one. Second, if you've already done research, educated yourself and/or consulted with a professional or trainer about sleep, rest and recovery, you probably won't be looking at this book (and I wouldn't either, if not conscripted to respond as a part of the corporate consultancy). That said, for those who have already modified sleep habits, sleep environment, and other behavior related to sleep and rest, the survey does not clearly instruct respondents to account for that versus our natural tendencies before modification. As an example, my natural disposition is to stay up late, typically midnight to 1 a.m. or even later, and to awake at 7 a.m. I typically operate on 5-6 hours sleep, may feel times of fatigue which I power through, and catch up with an extra hour of sleep when able. However, after resuming intensive strength and cardio training and athletic competition, I got "religion" about rest and recovery and modified sleep habits, environment and timing to optimize recovery. That matters, because I responded to the survey based on my modifications, not my natural predisposition. I assume Breaus is interested in the natural predisposed habits and behaviors, for purposes of his chronotyping. That may explain, as well, why his attempts to characterize personality and behavior traits based on his rigid chronotype categories is so wildly off-base in my case--I intentionally adopted the sleep habits of another category in part, but in fact am a much closer fit on a continuum along two others. Be aware of these points when you take his survey and when reading back the results. I endorse the other reviewer's suggestion to take his survey online and then assess whether you think the initial readout you get is a fit--if so, you may benefit and if not don't waste your time. I give the book two stars for the above reasons, the limited utility of Dr. Breus' approach here, and because, while the book indeed contains good information that is going to be useful to the reader, none of it is unique to this book and is readily available in materials that stick closer to the peer reviewed research in the field and steer away from the gimmicky and I think flawed attempt at rigid typology that might confuse and mislead readers unnecessarily. Honestly, there seems little doubt about the validity of Breus' credentials, but he's not the only bona fide specialist who seems more fixated on marketing his branded products than good research and its proper application to individuated cases. That said, if you take the online survey and it clicks for you, Breus certainly includes a range of research and data-based ideas and recommendations you may find helpful if you haven't already looked at the generally available guidance on age-based sleep requirements, quality of sleep relative to rest and recovery values, diet and nutrition related to sleep, pre-sleep habits like avoiding certain meals and substances, avoiding blue screen viewing (video or e-readers or poring over your iPhone texts and emails) just before bed, and keeping the room quiet, dark, cool (65-68 degrees), as well as free of video monitors and electronic devices while sleeping. There's good information about bedding, and bed clothes (or lack thereof). There's good information about rhythms, jet lag, alert and aroused states, and optimal times to perform certain activities in light of that information. A lot of it is provided in this book, and all of it is available elsewhere. Other reviewers have already addressed the fact that the book also fails to adequately address those who do shift work or are otherwise required by the mandates of operations and work schedules, to be awake and functional outside the lines of their optimal waking period and can't sleep in accordance with their optimal sleep guidelines.