Managing Fatigue
Kirsty McCullochUniSA, Centre for Sleep
Research
When I die, I want to go peacefully,
Like my grandfather didIn his sleep…
Not screaming like thePassengers in his car!!
Background
Module One
In 1910 average sleep length was 9-9.5h
In 1913 tungsten-electric illumination introduced
In 1990 average sleep length was 7.5-8h
Caff
ein
e (
mg
/head
/day)
1910
1930 1950 1970 1990
Sle
ep
(h
rs)
10
9
8
7
500
400
300
200
100
Sleep length versus caffeine consumption 1910-90
Fatigue Definition
• Fatigue is the consequence of inadequate restorative sleep
• Fatigue is an experience that results physiological performance decrements and psychological functioning
Exercise
•Name some of the conditions
that make you feel
particularly tired or fatigued
at work
Causes of Fatigue
Work-related
Hours of work
Workload & environment
Non work-related
FATIGUEFATIGUE
Situation & lifestyle
Medical disorders
Joint Responsibility
Work-related
Hours of work
Workload & environment
Non work-related
FATIGUEFATIGUE
Situation & lifestyle
Medical disorders
Organisational Responsibilities Employee Responsibilities
Consequences of Fatigue
Module Two
Accident Risk
• 10-40% of road accidents involve driver fatigue (Shafer, 1993)– 5-15% of all fatal road accidents
(Hartley et al, 1997; Wang & Knipling, 1994)
• Fatigue is 4 times more likely to cause workplace impairment than drugs or alcohol (Akerstedt, 2000)
• Increase in fatalities beyond the 9th hour of work (Nachreiner etal, 2000)
Comparing Fatigue and Alcohol
• 40 subjects
• 2 experimental conditions•Sleep deprivation (28hours)•Alcohol (one standard drink every
30 minutes from 8:30am)
• Performance measured half hourly via computer based test
Comparing Fatigueand Alcohol
U N P R E D I C T A B L E T R A C K I N G
(CONTROLLED BYJOYSTICK)
CONSTANT MOVEMENT
Comparing Fatigueand Alcohol
-30
-20
-10
0
10
20
0.00 .025 .045 .065 .085 .10+
FIG. 5. Mean relative performance levels for the unpredictable tracking task in the alcoholintoxication (left) and sustained wakefulness condition. The equivalent performance decrement at aBAC of 0.05% and 0.10% are indicated on the right hand axis. Error bars indicate + one s.e.m.
Blood Alcohol Concentration (%)
3 7 11 15 19 23 27
0.05
0.10
Hours of Wakefulness
• Australian road statistics show that night shift workers driving home have a 4 to 7 times higher chance of having an accident
• What will help? Caffeine, a nap plus time to wake up, interesting conversation
• Above all else, pull over if you are fighting sleep because you cannot know the point at which you will fall asleep
Commuting
One of the greatest ‘costs’ of shiftwork and fatigue is paid by families
This is evidenced by: - increased divorce rates- learning difficulties for shift
workers’ children- increased domestic workload- difficulties with childcare; and - decreased involvement in daily
family life
Shiftwork and families
•Shiftworkers frequently cite social disruption as a major stress
•Many shiftworkers will choose to participate in social or community activities in preference to sleep
•If it is appropriate, inform your friends of your work times in advance of their event planning
Shiftwork and social life
“Shiftwork is probably bad for the heart, almost certainly bad for the head and definitely bad for the gut”
Monk &
Folkard, 1992
Shiftwork and health
Smoko Break
Managing the Risk
Module Three
A New Way of Thinking
• Fatigue-related accidents are no longer
viewed as ‘diminished responsibility’,
but as a result of ‘voluntary impairment’
• Liability for accidents is now extended
beyond the individual, to the
company and other
stakeholders
The Magic Cure
Sleep Obtained During Breaks
02468
1012141618202224
Time of Break Onset
7 hrs sleep
6 hrs sleep5 hrs sleep4 hrs sleep3 hrs sleep2 hrs sleep
1 hr sleep
120
0
140
0
160
0
180
0
200
0
220
0
000
0
020
0
040
0
060
0
080
0
100
0
Len
gth
of
Bre
ak
Napping
• Cannot be achieved by everyone
• Can be a powerful supplement to sleep but cannot replace it
• Naps 10 minutes or longer may provide benefits such as improved alertness, communication & mood
• Allow for 15 to 20 minutes wake-up time for sleep inertia to pass
Alcohol & Sleep
• A couple of drinks before bed has no negative consequences on sleep but it is not a recommended strategy
• At higher levels, that is four or more drinks, alcohol acts as a sedative to promote being unconscious
• In addition, at these levels the structure and function of sleep can be negatively effected
Caffeine
• Has stimulant effects that can improve alertness and performance
• Is most effective when used strategically; that is, not all day every day but when you really need help staying awake
• Can be effective for up to 4 hours
Caffeine Levels in Common Drinks
• Instant coffee: 1 teaspoon contains approx. 80 milligrams
• Brewed, plunger or espresso coffee: 1 cup contains between 80 and 120mg
• Herbal tea: 1 cup contains from 0 to 30mg
• Normal tea: 1 cup contains approx. 60mg
• Others: 200ml Red Bull 80mg, 500ml Jolt cola 100mg, 375ml cola 50mg
Foods that Alert Us
• Some studies have shown that eating low-fat high-protein foods can increase alertness
• These foods must be low in fat because high-fat foods will slow you down
• The effect is subtle and may be noticed after approximately 30 minutes
• It is recommended that at least 100 to 120 grams of an appropriate food is eaten
Foods that Alert us• Fish: cooked or tinned
• Low-fat dairy: cottage cheese, yoghurt
• Lean meat: steak, chicken breast, lamb
• Others: hard boiled eggs, protein powder
• NOT deep fried food, nuts, fatty meats or pies, full cream dairy products
Foods that Slow us Down
• Research shows that processed carbohydrates can give a ‘sugar hit’ but ultimately slow us down
• Processed carbohydrates convert to simple sugars (the ‘sugar hit’) but insulin quickly reduces blood sugar levels
• Examples: cakes, lollies, sweet biscuits, soft drinks, white bread, chocolate etc
‘Good’ Carbohydrates
• Any fresh fruit or vegetable
• Wholegrain breads, pasta, cereals and brown rice
• Rice cakes, popcorn
• These ‘good’ carbohydrates have not been found to have any negative effect on alertness
Hydration
• Dehydration slows you down and increases feelings of lethargy
• Working in heat, air conditioning or at night is likely to be dehydrating
• Drinking coffee, tea, soft drinks, cordial and eating salty foods can also make it worse
• Adults should drink at least 2 litres/day
Exercise
• Is obviously good for health and fitness
• May have significant benefits on the quality and quantity of your sleep
• Doesn’t need to be extreme; any activity that keeps your heart rate constantly elevated for at least 20 minutes is good
• Suggested activities include a brisk walk with the dog, swimming, jogging, riding
Relaxation
• If you can’t get to sleep after 30 minutes in bed, get up and do something relaxing
• This can be anything from reading the paper or a book to listening to music; try not to do anything too physical
• Many people have also reported considerable benefits of learning relaxation techniques like meditation or yoga
Finally…
• Managing fatigue will always have its challenges
• There are no golden rules but practical information helps good decision making
• Appropriate solutions will depend on your age, household structure, sleeping environment and any medical condition
• Individual differences will determine your ability to recover from various work regimes and fatigue
Questions??
Contact Details:Centre for Sleep Research, UniSAL7 Playford Building, City East
p: (08) 8302 6624f: (08) 8302 6623
