Apple CEO Tim Cook wakes up every day at 3:45 a.m. I tried doing it for a week, and it made me shockingly productive.

With seven hours of sleep under my belt, 3:45 a.m. came quickly. I bolted out of bed — lest I fall back asleep — and immediately embarked on my day: exercise, shower, and settling down to work.

The good news was that even with a 30-minute high-intensity workout at the start of the day, I was at my desk by 5:30 a.m., and I was able to accomplish by 9:30 a.m. what usually takes me until noon. Barely an hour after many people have breakfast, I had already accomplished half my workday. And even though it's really only a few hours sooner, psychologically I felt a huge boost from seeing major to-do items cleared off my Trello board so early in the day.

In fact, this felt like a great time for an email break. I usually hide from email — with so much work on my plate, I often delay dealing with messages because I'm so nervous about getting work done. But now I could comfortably take an hour to deal with email without anxiety. Major win for the 3:45 a.m. wake-up.

Monday was a great start. Despite not wanting to get out of bed, my energy was high throughout the day, and I managed to shut down about 6 p.m., feeling productive and confident.

Unfortunately, bedtime slipped to nearly 10 p.m. Monday night, but I told myself it was fine — I'm used to getting by on about six hours of sleep anyway. When the alarm went off, I again leapt into action. As a creature of habit, I like keeping to a schedule, and I was eager to exercise, shower, and settle down to work.

This was the day, though, when I noticed a distressing trend about my eating habits while on the Tim Cook schedule. I am not generally much of a breakfast person. Sometimes I'll have a breakfast bar, but that's about it. But when you get out of bed at 3:45 a.m., lunch is eight long hours away.

On both Monday and Tuesday, I had noticeable hunger pangs, and took a break around 7 a.m. for breakfast. But I wasn't done — by 10 a.m., my stomach was growling again and I snacked some more. It might be purely psychological — if lunch is just four or five hours after the work day starts, I can wait it out. But eight hours demands a worrisome number of snack breaks.

On the other hand, I discovered that waking up at 3:45 a.m. on the West Coast is an extraordinary advantage for folks like me who need to communicate with people in New York. Usually, when I open Outlook at 8 a.m., it's already 11 a.m. on the East Coast, and I'm playing catch up with email sent to me hours earlier. I don't like feeling a step behind, which is something else that typically ratchets up my anxiety during the day.

But today I realized that if I rescheduled my morning, I could take a break to manage email around 6 a.m., which lets me send morning email before many East Coasters even show up to the office. Getting up early levels the time-zone playing field, and that's awesome.

Unfortunately, there was no 8:30 p.m. (or even 10 p.m.) bedtime for me today. Thanks to a show for which I'd been holding reservations for weeks, I didn't get home until 11 p.m. With an energy level too low to be measured by modern science, I crashed a half hour later.

Wednesday was not a good day.

Operating on the kind of fumes you get from four hours of sleep, I was a zombie right from the moment I woke up. Unable to even bear the thought of burpees, I sat in bed for a half hour, checking the news and following the Twitter activity about a story I had published the day before.

I actually wanted to dedicate some time to email, but my inbox was empty. This is the flipside of the early morning email advantage I discovered yesterday. It's so early that even the spambots aren't awake yet, much less anyone with something important to say to me.

And Wednesday dragged like that all day long. Since I skipped my morning exercise, my energy level stayed low all day, and I made even worse diet choices than the day before.

I really started to question the wisdom of my new schedule, and was remarkably unproductive all day, taking frequent social media breaks when I really should have been writing or researching. I called it a day a little on the early side, but anxiety about deadlines sent me back to work for a few hours after dinner. In the end, I didn't get to bed until about 10 p.m.

Despite the fact that my alarm continued to go off at 3:45 a.m. — a solid three hours earlier than my usual wake up time — I was starting to normalize the experience of getting up before the roosters.

Already used to having the extra time to work, feeling behind the eight ball from the day before, and sensing the week ending with large deadlines looming, I made the decision to skip my daily workout for the second day in a row — this time because I didn't think I could spare the time.

Let's be clear about this — that was the wrong decision. Tim Cook clearly has time to go to the gym every day, and he runs the world's most profitable company. I should have been able to spare a half hour out of my newfound morning time, but I was gripped by irrational work anxiety.

And as I suspected might happen, my bedtime had managed to creep back to my usual time, while I continued to get up at 3:45 a.m., which I know is not healthy. I could really feel the lack of sleep starting to affect my alertness, energy level, and mood. By the early afternoon, I had a headache that affected my ability to concentrate.

Despite again not getting enough sleep (I went to bed at about 10 p.m. Thursday evening), I woke up full of energy, probably because I subconsciously knew I was going to sleep in over the weekend.

Looking back on the week, I realized something else I liked about settling down at my computer at 5 a.m. — it was still pitch black outside. With sunrise not until 7:22 a.m., I got to work for over two hours with the view out my window shrouded in darkness. Your mileage may vary, but I found that exhilarating, and it genuinely made me more productive.

For my last day, I was back on schedule: exercise, shower, work for a while, and then email. Then I was back to work until lunch. In the afternoon, I worked in 25-minute, Pomodoro-like chunks on a few different projects, and got to stop the workday by 6 p.m., knowing I'd do a little more work on the weekend to catch up.

Read more: I divided my work day into precise 25-minute chunks — and it was the key to staying disciplined while working from home

And so ended a week of waking up with Tim Cook.

It seems to me the mistake a lot of people make when trying to imitate the habits of successful people is that they don't really internalize the underlying reasoning behind the activity.

When we hear a CEO wakes up at 4 a.m. or declares email bankruptcy or never works on any single project more than 25 minutes at a time, we often rush to try it ourselves.

If you don't have insight into the context of why these techniques work for them, trying them for yourself can be a catastrophe.

The 3:45 a.m. wake-up works for Tim Cook no doubt because he spends every moment of the business day in meetings, and this schedule gives him time to care for his health, address his inbox, and reserve time for uninterrupted thinking.

But you and me? We should know our own "why" before committing to a change like this.

Personally, I liked working early — and even getting a head start on the East Coast — enough that I will definitely continue to do it. But not 3:45 a.m. It's simply not sustainable, since I still have regular evening activities and a desire to keep a little "life" in my work-life balance.

As soon as I was done with this experiment, I immediately transitioned into my new schedule — a 4:30 a.m. wakeup.

It's somewhat more forgiving of going to bed at 11 p.m. (as I will inevitably do with alarming regularity). It still gives me hours to work in the early morning darkness, to deal with email as the East Coast is rolling into the office, and to get a huge amount of work done by midday.

Hopefully, I can get my craving for mid-morning snacks under control. Thanks, Tim Cook, both for my gadgets and for a new way to approach my daily schedule.