The Mental/Physical Disconnect
Have you ever stayed up all night toward the end of a project, only to suffer from a huge slump in productivity the next day, or even several days afterward? IT professionals tend to work really hard to meet deadlines; then, following the crunch period, they crash just as hard.
Some desk workers have difficulty concentrating throughout the day. They stare at the computer screen, hoping that they'll somehow regain mental focus.
Many people bring work home, and some even drag it into bed with them at night. Ambitious technical workers might have trouble sleeping because they're attempting to solve problems in their heads, while at the same time trying to nod off. Mentally working through a bug fix or trying to think up a clever design is a far cry from counting sheep.
Even if you get plenty of rest, other issues might disturb your concentration. As physical beings, minor aches can prevent us from sitting comfortably. A sore lower back or stiff shoulders can make it hard to focus on your work, which can keep you from making progress on an assignment.
These are just some of the ways in which we humans might suffer from a misalignment of physical and mental focus, affecting our performance at work. What can desk workers do to keep their energy at peak performance levels? Many things can help, but this article will focus on five simple, basic life changes that can improve your work and boost the satisfaction you get from it.
Tip 1: Get the Sleep You Need
Sleep researchers have discovered that our bodies send us two different kinds of signals—one telling us to wake up, and the other telling us to go to sleep. We get each of these two signals twice a day. Typically the first wakeup call comes at around 6 or 7 a.m., and the second occurs at around 5 or 6 p.m. The average person gets a "go to bed" cue just after lunch, and then again at around 10 or 11 p.m. 
Scientists also report that each of us has a daily sleep requirement, and there's nothing we can do to change our personal quota. Some people need as little as 5 hours a night, and others need as much as 10 hours, but the average person needs around 7.5 hours of sleep. If you're a person who needs 10 hours of sleep, don't fret. Albert Einstein is said to have slept at least that much, and he managed to find the time outside his day job at the Bern patent office to change our understanding of physical reality.
Another important finding in the relatively new field of sleep medicine is that we accumulate a sleep debt. If you don't get your share of shuteye tonight and tomorrow night, you'll have to "pay back" that missing amount almost hour-for-hour at some point, whether next week or next year. Furthermore, as long as you have a debt, you won't be performing at your best. On the other hand, most people need a little sleep deficit to fall asleep, as few of us can just will ourselves to drift off.
It takes a week or so to get into an optimal pattern of sleep. During this adaptation period, try choosing your wakeup time, and let your body tell you when to hit the sack. Get up at the same time every morning, and go to bed only when you're so tired that you can't stay awake. If you feel sleepy during the day while you're working out this new sleep system, don't take a nap. You need to build up so much sleep deficit that your body forces you into a deep slumber at night.
Tip 2: Watch What You Eat and Drink
Our bodies put a lot of energy into the process of digesting food. If you eat a heavy lunch, you'll burden your system right about the time when you get your first cue telling you to go to bed. Caffeine and alcohol also upset our body rhythms. A large coffee in the morning might lift you up for an hour or so, but you'll pay back that boost—with interest—later in the day. Too much alcohol at lunch will accentuate your body's desire to sleep in the early afternoon.
As the old adage goes: Garbage in, garbage out. Look for breakfast foods that give you a slow, steady rise in blood sugar over a long period. A bowl of oatmeal or nutritious cereal in the morning does exactly that.
Replace at least part of your coffee intake with green tea. You won't get a jolt from green tea, but it will pick you up a little. It's also soothing, and it never causes a drop later in the day, like coffee does.
Be mindful of what you eat for lunch. If you stuff yourself with fried chicken and French fries, you probably won't get much done in the afternoon. On the other hand, if you stop eating when your stomach is only about 80% full (an Okinawan practice called Hara Hachi Bu) and stay away from greasy food, you'll have no trouble working after your midday meal.
Tip 3: Exercise Regularly
Fitness experts tell us that aerobic exercise makes you more energetic overall, but nobody is really sure how that works. The prevailing theory is that when your heart gets a regular workout, your circulatory system becomes more efficient, giving you a higher return on the oxygen and nutrients you bring into your body.
One mistake many people make is to jump right into an intense exercise routine. If you start out with a program that pushes your body too hard, you're likely to "throw in the towel" fairly quickly, and you'll wind up with less energy rather than more.
Get an aerobic workout on three separate occasions every week—preferably not on consecutive days, as your body needs time to recover between sessions. Exercise for an hour, if you can. Starting from scratch? Set aside 15–20 minutes for each drill, and build up slowly. After all, it defeats the purpose if you push yourself to the point of zapping your energy for the next two days.
Worried that all this exercise will take a big bite out of your free time? If you're an average person, awake around 115 hours a week, 3 hours of exercise amounts to an investment of just over 2.5% of your most precious resource, time. I wish I could come up with a way of quantifying the return, but suffice it to say that you'll notice the difference in your mood and overall productivity.
Tip 4: Optimize Your Work Posture
Instead of sitting at your desk all day, find ways of working on your feet from time to time. Consider getting a standing (or standup) desk, or try holding standup meetings. If your job leaves you stuck in a sitting position at your desk, get up and walk around or march in place for five minutes once every hour.
Do small stretches throughout the day. One way of stretching all your "big muscles" is to get up and reach both hands toward the ceiling for one minute. Do this stretch three times a day, and you'll probably feel less scrunched when you sit back down.
Tip 5: Align Your Daily Schedule with Your Body's Natural Rhythms
On three separate days, once an hour note any changes in your physical energy, concentration, wakefulness, and outlook. Look for patterns that occur on different days. By doing this tracking, you'll get a pretty good idea of your personal rhythms, and you can align yourself accordingly.
Above all, don't forget about play and relaxation. You need variety in what you do during a given day. If you don't allow yourself to have a little fun and laughter every day, you'll find it's harder to focus when you need to get serious and concentrate.
If you can mix play and work, you'll be ahead of the game. The more fun and passion you bring to your occupation, the more energy and focus you summon.
There you have it—five relatively simple changes that you can make in your life, without a huge commitment of time, equipment, money, or even effort. You don't have to tell anyone you're doing it. But if you can take advantage of at least one or two of these ideas, your capabilities at work will very likely improve, and someone will probably notice enough to compliment you. Better yet, not only will you do a better job; you'll also feel good while you do it.
Let's try not to squander the seconds in each day; they add up. If we can just master the moments, the hours will take care of themselves.
 William C. Dement, M.D., Ph.D., and Christopher Vaughan, The Promise of Sleep: A Pioneer in Sleep Medicine Explores the Vital Connection Between Health, Happiness, and a Good Night's Sleep. Dell, 2000.
 Lawrence J. Epstein, M.D. and Steven Mardon, The Harvard Medical School Guide to a Good Night's Sleep. McGraw-Hill, 2006.
 Tuomo Rankinen, Ph.D. and Claude Bouchard, Ph.D., "Dose-Response Issues Concerning the Relations Between Regular Physical Activity and Health." President's Council on Physical Fitness and Sports Research Digest (Sept. 2002), Series 3, No. 18.
 Michael L. Pollock, Ph.D., et al., "American College of Sports Medicine Position Stand: The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." Medicine & Science in Sports & Exercise (June 1998), Vol. 30, No 6, pp. 975–991.