The Difference Between Sleep and Napping
Next to food and water, sleep is our body’s most non-negotiable need, and if we don’t get enough, our mental and physical performance can quickly deteriorate. You already know that most people should get the mythical eight hours of sleep, but as we’ve seen, different people have slightly different needs. No matter your chronotype, your body needs a daily opportunity to rest and refresh itself.
Some people find naps are a great way to recharge and relax, whereas others find they interfere with their sleep that night and only leave them feeling groggy. However, not all naps are the same, and it’s worth understanding the different types so you can nap strategically for your chronotype.
Kinds of Naps
• Recovery naps are the kind that make up for sleep deprivation the night before.
• Appetitive naps are taken just because you enjoy napping! You might find they simply relax you and improve your mood and energy levels.
• Prophylactic naps are taken in advance to prepare for an anticipated period of sleep deprivation—for example, a late night or shift work.
• Essential naps are when you’re ill and you need to rest deeply to give your immune system time to fight off infection. Your body will often force you to sleep whether you want to or not.
• Fulfillment naps are for children who need more sleep than adults do. They can occur spontaneously or be planned throughout the day for babies and toddlers.
Bearing in mind the natural phases of sleep, a five-minute nap is simply too short to take you into the deeper, restorative phases. After thirty minutes, your body can go into the deeper sleep phases, but then there’s another problem—you are no longer napping but full-on sleeping. Waking from this can leave you groggy, not refreshed, and interfere with your sleep that night. So-called power naps are in between, at around ten or twenty minutes.
Daily sleep is essential, but are naps necessary? Recovery naps, prophylactic naps, and essential naps are all useful and play their part. Other naps can be good or bad, depending on their length, their timing, your age, and what you do immediately afterward.
“Homeostatic sleep drive” refers to, essentially, feeling sleepy. Like hunger builds the longer you don’t eat, sleep drive builds the more you don’t sleep. Napping can lower this sleep drive. This a good thing in that being less sleepy means you can perform better, focus, learn better, and even self-regulate your mood more effectively. However, it’s a bad thing if decreasing your homeostatic sleep drive results in you not being sufficiently tired to sleep that night. You could establish a vicious cycle of insomnia.
As you can see, the advantage and disadvantage of naps is really the same thing. Reducing sleep pressure can combat fatigue in the short term, but exacerbate it by interfering with your natural sleep patterns. If you constantly need a nap, you may in fact be trying to compensate for a broader sleep problem—or the naps themselves may be the problem!
People who have difficulty going to sleep at night should avoid napping (for example, dolphin chronotypes). The best way to know that napping isn’t right for you personally is to notice its effect on your sleep cycle. If napping makes you sleep later in the evening and wake later the next morning, then you may be so tired the next day that you feel you need another nap—and the cycle continues. Generally, it’s best to stick to occasional recovery or essential naps and push through any fatigue so you continue to build up sleep pressure and sleep deeply that evening instead.
If, however, you are the type of person who finds naps useful and refreshing—without compromising their sleep—then there are a few ways to optimize your nap.
• Keep it from ten to twenty minutes only
• Nap halfway between the time you wake up and the time you sleep—this will vary for chronotypes. Avoid napping a few hours before bedtime.
• Nap in a cool, quiet, dark place that is comfortable and private.
• Use relaxation techniques to clear your mind and set aside worries so you’re not ruminating instead of resting.
• Notice how you feel after napping and the broader effect it has on you, and adjust accordingly.
Naps can be a great way to refresh yourself, boost alertness, and feel more relaxed. Avoid napping if a) you suspect the desire to nap may be masking a bigger sleep issue, or b) the napping habit itself is interfering with your circadian rhythms.
One thing to remember is that you don’t necessarily need to fall asleep to rest and recuperate. You can rest your brain, recenter yourself, and clear your mind with a bout of meditation, a breathing exercise, or a relaxation technique—all without compromising your sleep quality later that night.
Now, let’s return to the question of blood sugar and how you can manage it for optimum energy levels throughout the day.
Eating for Glucose
Eating for energy consists mainly of focusing on blood sugar levels. You can think of the amount of readily available glucose in your bloodstream as a physiological analogue to “energy”—it’s the literal fuel you need to power everything in your body, including the thoughts in your brain. However, there are consequences for having both too much and too little: you know the consequences for too little glucose, but with too much, the body will overcompensate and create a “crash” effect in your energy levels. Keep your blood sugar levels constant and moderate, and the machine of your body will be well-functioning.
The easiest way to start thinking about blood sugar levels is to talk about the glycemic index (GI). The GI is a measure of how quickly your body breaks down different foods, mostly carbohydrates, into glucose. In other words, it measures how much and how quickly a food will affect your blood sugar levels. The higher the GI, the more quickly it evaporates into your bloodstream as glucose.
After a typical meal, your blood sugar level spikes and then insulin is released to regulate it. Your body has ways to keep your blood sugar in a relatively stable range—i.e. releasing stored energy from muscle, liver, or fat tissue when blood sugar is low, or releasing insulin to usher excess away when blood sugar is high. When the body detects a large amount of blood sugar, a proportionately large amount of insulin is released, and this is what creates the aforementioned crash effect on energy levels.
Thus, the goal with eating for glucose and abiding by the glycemic index is to try to keep your blood sugar levels as constant as possible. Avoid energy peaks and crashes, and instead cultivate sustained, moderate energy throughout the day. You can do this by understanding timing and food selection.
The lower the GI of a food, the less extreme its effect on the insulin response and the more slowly and steadily it releases sugars into the blood. The result is stable energy levels and appetite. Foods with a higher GI cause the body to release huge spikes of insulin that then clear blood sugar more quickly, leaving you with a “crash” afterward—one that feels exhausting and can make you hungry all over again. Basically, lower GI foods lead to more stable blood sugar, energy levels, appetite, and mood, while higher GIs can cause us to feel extreme blood sugar and energy fluctuations, plus incite cravings that force us to eat more when we don’t need to.
The blood-sugar roller coaster is all about highs and crashes from eating refined carbohydrates and simple sugars. Though GI is not the only feature to look for in a food, it’s an important thing to consider with regards to energy. GI says nothing about the caloric value or the nutrient density of a food, so it’s worth remembering to use GI as only one factor of many when planning a diet for optimal energy.
Glycemic load (GL) is another measure, and essentially takes into account the quantity of carbohydrates you’re eating at any time, and the effect this has on your blood sugar. Portion size makes a difference. The higher the glycemic load, the higher the spike in blood sugar levels. Ideally, you want both the GI and GL to be as low as possible. Luckily, the foods with the lowest levels are conveniently the ones that are healthiest in other ways too—i.e. they’re packed with vitamins, minerals, fiber, and antioxidants.
There’s nothing wrong or unhealthy about carbohydrates per se, but the more refined varieties (i.e. the ones that are immediately converted into glucose) are more likely to lead to unstable blood sugar and the resulting energy spikes and slumps. Fruits and vegetables, after all, are carbohydrates too, but if a food also contains lots of fiber and water, its total glycemic load may be low enough to offset the fact that the bulk of its calories come from simple sugars. So, although things like bananas and potatoes are high-GI foods, they are natural, plant-based foods that still contain plenty of nutrition to outweigh any negative GI effects.
When planning a diet to optimize your energy levels, opt for small amounts of high-quality fats, plenty of protein, and carbohydrates primarily from plant sources. Avoid nutrient-poor refined carbs like cakes and white bread, sugary sweets, soda, white rice, and pasta. If you do decide to have them, try smaller portions and combine them with other low-GI foods so that the total meal’s GI is still on the low side. And of course, if you must eat high GI foods, eating them with fat and protein will aid in slowing the glucose absorption.
