I am fascinated by Chris Bailey. After hearing about his productivity experiments, you will be too.

Over the course of the year, Chris Bailey, author of the new book The Productivity Project, completed several personal experiments to assess which ones positively and negatively impacted his productivity. Let’s highlight some intriguing ones that worked, as well as a few that didn’t.

Working 90 Hours a Week

When Bailey was working 90-hour weeks, he got a lot done, but only during the first few days of the week. After that, he didn’t have the time or mental space to recharge, so his productivity dropped.

In the long-run, working long hours pushes you to procrastinate more, work less efficiently, and causes you to get less done. In fact, after 40 hours, Bailey reported that your marginal productivity begins to drop, until at approximately eight 60-hour weeks, the total work done is the same as what would have been done in eight 40-hour weeks. And with 70 and 80-hour weeks, you reach the break-even point in just three weeks.

Why does this happen? When you work excessive hours, that extra time has to come from somewhere, which may force you to push away the very things that reenergize you, like working out and spending time with loved ones. Then, you begin to fight a losing battle, and become stressed out, unmotivated, and ultimately less productive.

Bailey suggested that instead of working longer, work smarter. Step back from your work: spending more time planning (not just executing), scheduling less time for things, guarding and nurturing your energy levels, and reminding yourself of what’s most important.

Living in Isolation for 10 Days

Living and working without people interrupting him didn’t help Bailey’s productivity either. At the end of this experiment, he said he was less productive than he would have been normally. Everyone has a different definition of productivity, but most of the benchmarks Bailey uses involve people, such as how happy he makes other people, and the difference he’s able to make in people’s lives. When he took people out of that equation, he was either a) not able to accomplish much, or b) not able to accomplish much that was meaningful.

Bailey also shared that he “let himself go” when there weren’t other people around. Surrounded by more people, one tries harder to be a better person. And when he hit the lows of this experiment – taking three hours to fall asleep, battling a huge cold, and getting depressed, he had no social support network as a safety net.

Taking 3 Hour Naps

Bailey’s finding here? The format of a three-hour siesta is simply incompatible with Western cultures and won’t improve productivity if everyone around working traditional 9-6 business hours. Plus, even when Bailey was ultra-motivated and productive before his siesta, a three-hour break was enough time for him to lose motivation.

However, although long naps might not be helpful, short naps certainly are. According to Bailey’s cited research, napping improves memory, makes you more attentive and alert, helps prevent burnout, and boosts your creativity and ultimately your productivity. According to a NASA study on sleepy military pilots and astronauts, a 40 minute nap improved performance by 34 percent and alertness by 100 percent.

Bailey recommended that you nap at the time of day when your energy levels tend to dip. Ten to 20 minute naps have been shown to make you the most productive. If you can’t nap when your energy flags, take a break, and if you can’t take a break, schedule less important activities instead of the ones that require the most focus.

Meditating 35 Hours Over 7 Days

Bailey’s the first to admit that he’s a huge fan of meditation. He said that a computer’s RAM is like its short-term memory. By having a singular focus during meditation, you clear your mind of thought, which not only works out your attention muscle, but also clears your brain’s RAM. This reduces stress and allows you to focus better throughout the day.

Bailey found that a lot of meditation made it much easier to identify the highest leverage activities in both his work and personal lives. Meditation let him step back from the things he was doing so he could see the whole forest instead of just the trees. He could also achieve flow, which is that feeling of being completely immersed and energized by something. Finally, it allowed him to procrastinate less and get more done in the same amount of time.

Meditating for 10 minutes a day is apparently better than meditating for 70 minutes once a week. Bailey suggested meditating frequently, even if that just means sitting comfortably for a few minutes. It’s okay if your mind wanders – you will still receive the benefits.

Using Your Smartphone Only 60 Minutes a Day

Bailey had this epiphany with his smartphone experiment:

Your smartphone is like a little black hole in your pocket that sucks you into its vortex dozens of times every day. If you pick it up when you’re in an elevator, on a bus, or going for a walk, it sucks up 100 percent of your attention as you use it. Just as a practice like meditation can help you work out your attention muscle, I think losing control of your attention, like when you become completely absorbed in your cellphone, can do the opposite.

Bailey’s most productive ideas come from out of the blue, especially when he is bored. So leaning on his smartphone when he’s bored is, at least in the long-term, a pretty unproductive thing to do – especially because most of the things he does on his phone are a waste of time. They involve diluted social interaction, bite-sized status updates, and other things that have a very short shelf-life.

Bailey’s conclusion? Smartphones are useful and even necessary, and severely limiting their use can have an adverse impact on your productivity. However, you should identify the activities on your smartphone (and any wearables that resemble a smartphone) that will provide you with the highest return for your time and focus on those.