text: Chapter 11
  Sleep Readiness
  The brain is the only organ or body part that requires sleep. Sleep is crucial for tissue
  repair and hormone synthesis to maintain peak performance mentally and physically.
  Sleep sustains brain and physical health, cognition, the immune system, and recovery
  after physical activity. This chapter provides tools and techniques for leaders and
  individuals exercising sleep readiness tactics, techniques, and procedures for a range
  of occupations and operational environments.
  PRINCIPLES
  11-1. There are three basic interrelated principles of sleep health: sleep duration, sleep timing, and sleep
  continuity. Of these, sleep duration is paramount because the health and functioning of the brain is primarily
  a direct function of the amount of sleep obtained—the more sleep obtained the better. Sleep timing is critical
  because the brain’s internal clock strongly influences the ability to initiate and maintain sleep as well as
  maximize the amount of sleep obtained. The extent to which sleep is undisturbed by arousals and
  awakenings—sleep continuity—is important because this influences both the duration and the depth of sleep,
  with deeper sleep being more restorative. Ultimately, the promotion of sleep health in the operational
  environment entails optimizing each Soldier’s sleep duration, timing, and continuity to the greatest extent
  possible, given existing mission constraints. See ATP 7-22.01 for H2F testing and ATP 7-22.02 for drills and
  exercises. See also ATP 6-22.5 for further discussion on the leader’s role in sleep readiness.
  SLEEP DURATION
  11-2. Cognitive ability and readiness vary as direct function of the amount of sleep obtained. The more sleep
  Soldiers get, the greater their mental acuity, with faster response times, fewer errors, and fewer lapses in
  attention. Also improved are judgment, problem-solving, situational awareness, mood, resilience, and general
  well-being—to name but a few key Soldier attributes.
  11-3. Soldiers and leaders frequently ask “what is the minimum amount of sleep needed to maintain military
  effectiveness?” There is no clear threshold amount of sleep below which effectiveness is compromised and
  above which effectiveness is sustained. Most Soldiers need 7 to 9 hours of sleep every 24 hours to maximize
  health and sustain performance. The relationship between sleep duration and cognitive readiness (and thus,
  military effectiveness) is best thought of as a continuum, with more sleep always producing improved
  performance. Considered this way, the question becomes: “How can the amount of sleep obtained by Soldiers
  be maximized, given the constraints imposed by the current mission?”
  SLEEP TIMING
  11-4. Human beings are diurnal, designed to be awake during the daytime and to sleep during the nighttime.
  A portion of the brain that serves as an internal clock—sensitive to the timing of sunrise in the morning and
  sunset in the evening—largely controls these sleep-wake tendencies. This sensitivity keeps the brain’s clock
  synchronized with the outside world. During those hours that the brain’s clock has learned are local daytime
  hours, the brain produces output that facilitates activity and wakefulness. During those hours that the brain’s
  clock has learned are nighttime hours, it signals brain deactivation, thus promoting sleep. People who work
  at night might be less productive and less well-rested since they work when their brains promote sleep; and
  they try to sleep when their brains promote wakefulness. Likewise, this is what causes “jet lag.” After rapidly
  crossing multiple time zones, the brain’s internal clock is initially out of synch with the local day-night cycle,
  sending out signals to promote sleep during daylight hours and sending out signals to promote wakefulness