Lecture 8: Sleep

Question 1

Sleep is an activity

Answer 1

• Shown through EEG
• Sleep is not a stable state
• Different stages = shown in different brain waves
• Hipnogram = graph shows how someone progresses through stages overnight
• Deeper sleep is concentrated in first half of night
• Go through cycles = about 90mins
• Dreaming occurs more in second half of night

Question 2

Functions of sleep

Answer 2

• Physiological recovery
• Immune system
• Emotional balance
• Learning

Question 3

How long should we sleep?

Answer 3

• 7-9 adults, 8-10 teenagers
• Great variability though
• Presumed athletes might need more sleep than average individual

Question 4

Sleep in elite athletes (Knufinke et al. 2018)

Answer 4

• 40% of elite athletes feel insufficiently refreshed in the morning
• Measured using ‘fitbit-like’ sleep watch, simplified EEG
• Higher levels of deep sleep

Question 5

Sleep-regulating processes

Answer 5

1) Homeostatic sleep drive (process S)
- Longer awake -> more tired we become
2) Circadian drive for arousal (process C)
- Driven by light + temp

Combo of these 2 process -> sleep pressure
Hard to fall asleep = too high temp, mess up bio clock

Question 6

Sleep hygiene

Answer 6

• Behaviour and circumstances that positively influence sleep regulating processes

Question 7

Sleep loss & alterness

Answer 7

• Decrease responding with sleep loss
• One night has little effect but accumulated sleep loss leads to increased disastrous effects
• People get used to feeling sleep deprived = may feel okay but slow RT

Question 8

For sports performance

Answer 8

• Sleep affects = alterness + attention
  = learning + performance
  = injury prevention
• Study on sleep extention (Mah et al. 2011)
  = normal sleep (6hr40min)
  = extended sleep (8hr45min)
  = results -> subjective sleepiness decreased, increase in free throws etc.
• Sleep restriction (Fullager et al. 2014)
  = gross motor skills -> small/inconsistent effects
  = fine motor skills -> stronger effects
  = Larger effect with increased time awake

Question 9

Natural between-day variation in sleep

Answer 9

• Negatively affects RT

- Does not have (systematic) effects on sport-specific performance

Question 10

Powernapping

Answer 10

• Short period of daytime sleep
• To compensate for lack of sleep, recover from training session, prepare for evening match
• Many athletes + coaches recognise positive effect but <20% of athletes nap on regular basis
• Consider training = longer naps can reduce cognitive functioning when awaking but have longer positive benefits