WHEN TO EXERCISE: THE ULTIMATE GUIDE
I’ve focused mostly on the emotional and cognitive aspects of our lives. But what about the physical? In particular, what’s the best time to exercise? The answer depends in part on your goals. Here’s a simple guide, based on exercise research, to help you decide.
Exercise in the morning to:
• Lose weight: When we first wake up, having not eaten for at least eight hours, our blood sugar is low. Since we need blood sugar to fuel a run, morning exercise will use the fat stored in our tissues to supply the energy we need. (When we exercise after eating, we use the energy from the food we’ve just consumed.) In many cases, morning exercise may burn 20 percent more fat than later, post-food workouts.1
• Boost mood: Cardio workouts—swimming, running, even walking the dog—can elevate mood. When we exercise in the morning, we enjoy these effects all day. If you wait to exercise until the evening, you’ll end up sleeping through some of the good feelings.
• Keep to your routine: Some studies suggest that we’re more likely to adhere to our workout routine when we do it in the morning.2 So if you find yourself struggling to stick with a plan, morning exercise, especially if you enlist a regular partner, can help you form a habit.
• Build strength: Our physiology changes throughout the day. One example: the hormone testosterone, whose levels peak in the morning. Testosterone helps build muscle, so if you’re doing weight training, schedule your workout for those early-morning hours.
Exercise in the late afternoon or evening to:
• Avoid injury: When our muscles are warm, they’re more elastic and less prone to injury. That’s why they call what we do at the beginning of our workout a “warm-up.” Our body temperature is low when we first wake up, rises steadily throughout the day, and peaks in the late afternoon and early evening. That means that in later-in-the-day workouts our muscles are warmer and injuries are less common.3
• Perform your best: Working out in the afternoons not only means that you’re less likely to get injured, it also helps you sprint faster and lift more. Lung function is highest this time of the day, so your circulation system can distribute more oxygen and nutrients.4 This is also the time of day when strength peaks, reaction time quickens, hand-eye coordination sharpens, and heart rate and blood pressure drop. These factors make it a great time to put on your best athletic performance. In fact, a disproportionate number of Olympic records, especially in running and swimming, are set in the late afternoon and early evening.5
• Enjoy the workout a bit more: People typically perceive that they’re exerting themselves a little less in the afternoon even if they’re doing exactly the same exercise routine as in the morning.6 This suggests that afternoons may make workouts a little less taxing on the mind and soul.
FOUR TIPS FOR A BETTER MORNING
1. Drink a glass of water when you wake up.
How often during a day do you go eight hours without drinking anything at all? Yet that’s what it’s like for most of us overnight. Between the water we exhale and the water that evaporates from our skin, not to mention a trip or two to the bathroom, we wake up mildly dehydrated. Throw back a glass of water first thing to rehydrate, control early morning hunger pangs, and help you wake up.
2. Don’t drink coffee immediately after you wake up
The moment we awaken, our bodies begin producing cortisol, a stress hormone that kick-starts our groggy souls. But it turns out that caffeine interferes with the production of cortisol—so starting the day immediately with a cup of coffee barely boosts our wakefulness. Worse, early-morning coffee increases our tolerance for caffeine, which means we must gulp ever more to obtain its benefits. The better approach is to drink that first cup an hour or ninety minutes after waking up, once our cortisol production has peaked and the caffeine can do its magic.7 If you’re looking for an afternoon boost, head to the coffee shop between about 2 p.m. and 4 p.m., when cortisol levels dip again.
3. Soak up the morning sun
If you feel sluggish in the morning, get as much sunlight as you can. The sun, unlike most lightbulbs, emits light that covers a wide swath of the color spectrum. When these extra wavelengths hit your eyes, they signal your brain to stop producing sleep hormones and start producing alertness hormones.
4. Schedule talk-therapy appointments for the morning
Research in the emerging field of psychoneuroendocrinology has shown that therapy sessions may be most effective in the morning.8 The reason goes back to cortisol. Yes, it’s a stress hormone. But it also enhances learning. During therapy sessions in the morning, when cortisol levels are highest, patients are more focused and absorb advice more deeply.
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* We can also explain this with some simple math. Suppose there’s a 2 percent chance (.02) that Linda is a bank teller. If there’s even a whopping 99 percent chance (.99) that she’s a feminist, the probability of her being both a bank teller and a feminist is .0198 (.02 x .99)—which is less than 2 percent.
* Here’s an even simpler method. What time do you wake up on weekends (or free days)? If it’s the same as weekdays, you’re probably a lark. If it’s a little later, you’re probably a third bird. If it’s much later—ninety minutes or more—you’re probably an owl.
2.
AFTERNOONS AND
COFFEE SPOONS
The Power of Breaks, the Promise of
Lunch, and the Case for a Modern Siesta
The afternoon knows what the morning never suspected.
—ROBERT FROST
Come with me for a moment into the Hospital of Doom.
At this hospital, patients are three times more likely than at other hospitals to receive a potentially fatal dosage of anesthesia and considerably more likely to die within forty-eight hours of surgery. Gastroenterologists here find fewer polyps during colonoscopies than their more scrupulous colleagues, so cancerous growths go undetected. Internists are 26 percent more likely to prescribe unnecessary antibiotics for viral infections, thereby fueling the rise of drug-resistant superbugs. And throughout the facility, nurses and other caregivers are nearly 10 percent less likely to wash their hands before treating patients, increasing the probability that patients will contract an infection in the hospital they didn’t have when they entered.
If I were a medical malpractice lawyer—and I’m thankful that I’m not—I’d hang out a shingle across the street from such a place. If I were a husband and parent—and I’m thankful that I am—I wouldn’t let any member of my family walk through this hospital’s doors. And if I were advising you on how to navigate your life— which, for better or worse, I’m doing in these pages—I’d offer the following counsel: Stay away.
The Hospital of Doom may not be a real name. But it is a real place. Everything I’ve described is what happens in modern medical centers during the afternoons compared with the mornings. Most hospitals and health care professionals do heroic work. Medical calamities are the exceptions rather than the norm. But afternoons can be a dangerous time to be a patient.
Something happens during the trough, which often emerges about seven hours after waking, that makes it far more perilous than any other time of the day. This chapter will examine why so many of us—from anesthesiologists to schoolchildren to the captain of the Lusitania—blunder in the afternoon. Then we’ll look at some solutions for the problem—in particular, two simple remedies that can keep patients safer, boost students’ test scores, and maybe even make the justice system