Filed under: Sleep
That “slow to wake up” feeling of grogginess in the morning has a name: sleep inertia. HPRC asked a sleep expert whether sleep inertia is a real threat to performance, and the answer may surprise you: While sleep inertia is a real phenomenon, the threat it poses to performance has never been seriously studied but probably isn’t as bad as you might think.
However, sleep inertia can be a serious issue when cognitive performance—such as problem solving and decision making—is called for immediately on waking. For example, physicians who are awakened by calls from nursing staff have been known to make serious errors. For most situations, though, it’s better to sleep (and pay down any “sleep debt”) rather than stay awake with the intent of being alert just in case you’ll be called on, our expert concluded.
If your head does need to be in the game quickly after awakening, call on some caffeine to help; it can give you the boost you need to get out of your sleep inertia. Popping in some caffeine gum when you wake up (but only when essential) can produce near-normal cognitive performance within about five minutes.
Sleep is essential for optimal performance! The recent Warrior Resilience Conference V hosted by the Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury included a session called “Scheduling Sleep – A Clear Mind, A Combat Edge,” which highlighted how sleep is critically important to:
- Moral judgment
All of these have a serious impact on performance—not only for Warfighters, but for everyone. Lack of sleep is also linked to increased risk of motor vehicle accidents, depression, substance abuse, weight gain, heart and kidney disease, reduced immune response, and loss of focus. Make it a goal to get seven to eight hours of sleep a night, and reap the performance and health benefits.
Regular physical activity can make you sleep better—but how close to bedtime should you exercise? While the general opinion has been that vigorous exercise within three hours of bedtime might negatively affect your sleep, new research is reexamining this belief. Some preliminary studies have found that exercise before bed (both moderate and vigorous) didn’t negatively impact sleep quality. However, more research is needed to better understand truly how exercise closer to bedtime can impact sleep. Remember—there are many factors that contribute to a good night’s sleep. Just be aware that if you exercise in the evening, it might affect how well you sleep at night. Check out HPRC’s Sleep Optimization section for additional information.
Total Force Fitness requires optimal performance, and optimal performance requires optimal sleep. One way to get your best sleep may lie in some of the subtle sounds you hear every day. You may have heard of “white” noise, a type of random, constant sound that can filter or mask surrounding noises. Studies have now found that another kind of sound—“pink” noise—can help your sleep be even more restful than actual silence. Unlike white noise, the volume of pink noise is essentially the same regardless of its frequency. (For serious audio buffs, here’s an explanation from Georgia State University’s “HyperPhysics” department.) When you think of pink noise, think of rain falling or the rhythm of a heartbeat. This kind of noise regulates and synchronizes with your brainwaves, which enhances the percentage of time you’re in a restful, stable sleep. Pink noise might be another strategy to add to your arsenal for getting better sleep. You can get recordings of pink noise from a variety of sources online—some even free—for your smartphone or other mp3 player or cd/dvd player. A little searching should turn up something you like. And read more about the importance of sleep and how it affects your performance.
According to a recent report about post-exercise recovery and regeneration for athletes, men over 19 and women over 18 needs 8-10 hours of sleep a night (plus a 30-minute afternoon nap, as needed) for optimal athletic performance.
Continuing good sleep habits established earlier in adolescence such as regular meals, early morning light exposure, and a nightly sleep routine remain important. However, it’s also important to monitor the effects of stress and changes in sleep due to training/military operations.
Even if you’re not an athlete, the recommendations above still apply, except that your total sleep needs are seven to nine hours a night to keep you at your best.
Some additional tips for sleep:
- Regular exercise during the day can help you sleep better at night.
- If you have a question about whether to exercise more or sleep, choose sleep!
- During the night, if you wake up and after 20 minutes haven’t gone back to sleep, get out of bed, do something relaxing, and then get back in bed. You’ll probably fall right asleep.
Also, for a better understanding of your current sleep habits, afterdeployment.org has an online “sleep assessment” that you can take. For more information on how to optimize your sleep, visit the HPRC’s Sleep Optimization section.
Did you know that missing a night of sleep can produce performance results similar to those of being legally drunk? Even losing just a few hours of sleep can result in accidents and poor physical and mental performance. Sleepiness can inhibit balance, coordination, concentration, and response time—creating “the perfect storm” for accidents.
Make sure your sleep is optimal by turning off your electronics and other distractions well before bedtime, exercising during the day, avoiding caffeine late in the day, and sticking to a consistent sleep schedule. If you are in a situation where sleep is hard to come by, try to squeeze in naps when possible. For more information and ideas, check out HPRC’s article on sleep and visit HPRC’s Sleep Optimization resources.
Do you know how much sleep you and your loved ones are getting—and supposed to be getting? Keep in mind the recommendations differ by age group. According to a report from Canadian Sport for Life on optimal sleep for athletic performance at all life stages:
- Children under the age of six need 13–16 hours of sleep daily, including longer nighttime sleep and fewer daytime naps as they get older.
- As girls reach the ages of 6–8 and boys reach 6–9, their sleep needs drop to 10–11 hours of sleep a night.
- Girls 8–11 and boys 9–12 need 9 ½ to 10 hours of sleep a night.
- Girls 11–15 and boys 12–16 need around nine hours of sleep a night.
- In addition to their nightly sleep, girls 6-15 and boys 6-16 need a 30-minute-plus nap between 2–4 pm every day.
For young children, meals—particularly breakfast—are an important part of establishing a reliable sleep routine, and as children age they should start developing a 15–30 minute routine before bedtime to get ready physically for sleep. This is also a great opportunity for some quality time between parents and children that you can all look forward to each night.
To make this goal easier, be sure your kids avoid computers and TVs (anything with electronic stimulation) for one to two hours before bedtime. Allow an hour to unwind before bed—try soothing music, reading, and dim lighting.
As children become teenagers, make sure they don’t start incurring a sleep debt by sleeping less than needed. Encourage them to keep regular sleep hours, get early morning light exposure, and carefully gauge their caffeine consumption close to bedtime.
The report mentioned above suggests using a sleep log (and provides a sample log) to get an idea of your and your child’s sleep patterns. Remember that the warrior athletes of tomorrow need to develop good sleep habits today!
Caffeine in moderate doses can boost both physical and cognitive performance. It can help maintain alertness when you are doing long boring activities such as highway driving. It is especially effective for enhancing alertness and mental performance when individuals are sleep deprived. However, if you can, it is better to get the sleep your body needs. The suggested level of intake for enhancing cognitive performance is relatively low—one or two cups of coffee or one or two energy drinks (about 80-200 mg of caffeine). Larger doses can cause side effects (e.g. nervousness, irritability, shakiness, and trouble sleeping). It is very important not to consume large amounts of caffeine before trying to sleep. Blood levels of caffeine peak at about 60 minutes and are maintained for approximately two to three hours. Thus, although each person is different, another dose after four hours may confer additional benefits for activities of long duration or when alertness must be maintained.
The bottom line is, more caffeine will not improve performance—and may actually degrade it due to various negative side effects at higher doses.
Operation Supplement Safety (OPSS) has now been launched to answer many of your questions about Dietary Supplements. Visit the OPSS section of HPRC’s website now to learn more!
For many students, sleep is often sacrificed for studying. If it comes down to one or the other, sleep may be the better choice. According to a 2012 study, when students sacrificed sleep for studying, it was harder for them to pay attention in class and perform well on tests or assignments the following day. Warfighters are students too, as they often have to learn on the job. So help yourself and your children to optimize learning by optimizing sleep! Check out HPRC’s “Sleep Optimization” section and articles in response to “Questions from the Field” about sleep for ideas about how to do so.
Our bodies know when to sleep thanks to “circadian rhythms,” which are regulated by our brains on a 24-hour cycle. Circadian rhythms are linked to core body temperature, so ideally you should always sleep between 0300 and 0500, when your core body temperature is lowest and your performance abilities are at their lowest. Keep in mind that your individual circadian schedule is based on where you are and takes cue from environmental factors such as the sun and from social patterns. When crossing time zones, your internal clock needs time to adjust, which can take several days. Factors that influence this adaptation are:
- how many time zones are crossed, and
- whether you fly eastward or westward—the former takes longer to adjust.
Keep in mind that, in order to make up sleep or to adjust to a new zone, the best times to sleep are between 0300-0500 or 1300-1500.
For tips on how to improve your quality or length of sleep check out HPRC’s Sleep Optimization section, and for information on how sleep loss impacts all of the areas of Total Fitness check out HPRC’s Overview on sleep loss.