Inadequate sleep and consequences + Interventions to promote sleep in athletes

Question 1

Sleep Needs

Answer 1

• Sleep needs vary by age:
  ○ New-borns (0-3 month old) 14-17 h
  ○ Infants (4-11 month old) 12-15 h
  ○ Toddlers (1-2 y old) 11-14 h
  § 10-12 h at night
  § 1-2 h during the day
  ○ Preschool (3-5 y old) 10-13 h + short naps
  ○ School age (6 - 13 y old) 9-11 h
  ○ Adults (18 – 60 y old) 7-9 h

Question 2

Inadequate Sleep

Answer 2

1. Not sleeping long enough
   ○ Sleep deprivation
   § not being able to sleep enough e.g. lots of assignments so stay up late + need to get up early
   ○ Sleep restriction = only use the term when intentionally restrict sleep such as in experimental conditions or when you undergo a therapy known as Cognitive Behavioural Therapy (CBT)
   § Intentionally limit the amount of time spent in bed
2. Poor sleep quality!
   ○ Obstructive sleep apnoea
   ○ Insomnia, anxiety disorders, depression
   ○ Chronic pain, others
   ○ Can disrupt sleep through the night in healthy people = going to toilet, temp changes

• Try to have most of your water throughout the day = 2 hrs before sleep have less water as kidney takes 2 hrs to go through its cycle

Question 3

consequences of inadequate sleep

Answer 3

• Hypertension
• Impaired cognition
• Craving for sweet + dense foods –> weight gain + obesity e.g. occurs a lot on shift work
• Increased risk of diabetes + CV diseases
• Decreased immune response
• Decreased sports perf
• Cranky kids

Question 4

cognitive processes and mood

Answer 4

• Impaired cognition
  ○ Decrease reaction speed (psychomotor vigilance test, PVT = simple reaction time test) + decrease sustained-attention
  ○ Worsen driving + operating machine skills = if sleep deprived (say 4 hrs of sleep for a few nights) can be equivalent to having an alcohol level of 0.05
• Impaired mood + behaviour
  ○ Irritability, agitation, hallucination e.g. both auditory + visual hallucination
  ○ Subjective sleepiness, aggression

NB Some sleep deprivation-resistant individuals behave differently to the norm!

Question 5

Short sleep linked to metabolic ill health

Answer 5

Concurrent health trends:
○ ↓ in average daily sleep duration
○ ↑ incidence & severity of obesity + metabolic syndrome
○ 35 epidemiological studies linking alteration in sleep time w/ adverse health outcomes
○ If have b/w 7-8hrs of sleep = these people tend to be normal weight (BMI under 28)
○ On the other hand people who get 6 hrs of sleep = tend to be obese (BMI of 31.5 or higher)
○ People who get too much sleep = greater than 9 hrs, have a high BMI = might not have enough time to exercise through the day as sleeping for longer

Question 6

Short Sleep duration - a risk factor for metabolic syndrome?

Answer 6

= affects glucose tolerance

Question 7

What are some different interventions to promote sleep?

Answer 7

Cherry’s or cherry juice = good for sleep as they consist of many ingredients that promote sleep
- ↑Actual sleep time, ↓nocturnal activity = a lot less restless, ↑urinary 6- sulfatoxymelatonin
○ ↓SOL = didn’t take long to fall asleep, ↓WASO, ↑TST, ↑SE, ↓ISI (insomnia severity index)

Question 8

Macronutrients and Sleep

Answer 8

Carbs, fats, proteins
* A high-CHO low-fat meal:
○ ↓SWS, ↑REM sleep compared w/ normal-balanced or low CHO high-fat diet
○ s (Phillips et al, 1975; Porter & Horne, 1981)
* A very low-CHO high-fat, high protein meal: - KETO diet
○ ↑SWS, ↓REM sleep (Afaghi et al, 2007)

• A high glycaemic index rice meal: consumed 4h before bedtime shortened SOL by ~10min compared w. a low GI meal (Afaghi et al, 2008)

Hypothesis
* During SWS your brain accrues glycogen = not really proven
* So if don’t consume enough CHO that forms glycogen, you require a lot more SWS to give yourself the opportunity to accrue glycogen in the brain
* On other hand if on high CHO diet = don’t need as much SWS = as hypothesis that there is still enough glycogen in the brain accrued from dietary intake

Question 9

High GI meal increases TRP level

Answer 9

• Insulin will stimulate specifically the selective muscle uptake of LNAA
• LNAA compete w/ TRP for entry into the brain
• Once in the brain TRP can be converted to serotonin + melatonin = + they promote sleep = so need a high ratio of TRP to LNAA - what does that is insulin = insulin moves LNAA into the muscles, leaving behind TRP + TRP enters the brain + is converted to serotonin + melatonin
• High GI meal essentially increases availability of TRP
• LNAA - Large neutral amino acids
• TRP - tryptophan

Question 10

Interventions to promote sleep

Answer 10

Sleep hygiene
* Sleep env
○ dark, cool, quiet
* Sleep-wake schedules = fairly regular b/w 30mins to an hr, should wake up at the same time every morning = eventually will make bedtime regular
○ Consistent
* Incorporate a 30 min quiet relaxation period prior to bedtime
* Avoid screen time at bedtime - filter out blue light
* Keep stimulant (caffeine, + certain foods) use to AM
* Avoid alcohol + nicotine – sleep disruption
* Avoid sedating med (antihistamines, benzodiazepines) – not shown to benefit perf but potentially addictive - best pill melatonin
* Avoid early morning/ late evening training/ comps = sometimes out of control
* Daytime nap + perf (?)

Question 11

Experimental evidence: Sleep extension Mah et al, 2011

Answer 11

• Stanford Uni men’s varsity basketball team, N=11
• Mean age: 19.4±1.4y
• Baseline: sleep-wake schedule monitored for 2-4 weeks
• Intervention: 5-7 weeks sleep extension (minimal goal: 10h in bed each night –> ↑ by 110.9 min (on average)
• Sleep extension yields:
  ○ Faster timed sprint (on average by 0.7s)
  ○ Improved shooting accuracy (on average by 9%)
  ○ ↓ psychomotor vigilance test (PVT) = improved = arrow could be around the wrong way
  ○ ↓ excessive daytime sleepiness
  ○ ↑ mood