Firefit Conference 2008
‘Fit for Service, Fit for the Future’
Physiology of Ageing
- and possible effects on firefighters
Kevin Sykes
Professor of Occupational Health & Fitness
Director
Centre for Exercise & Nutrition Science
University of Chester
“So, Mr Jones,
how old are you?”
“32?”
If you didn’t know how old you are……..
….how old would you think you are ?
Many of us are health-conscious
But many still take their
health for granted…..
… until they lose it!
Prevention is better than cure
Increase in Life Expectancy
Females live 5yrs
longer than
males
2005
1950-2005
We can now expect to live 10 years longer than in the 1950s
UK Life Expectancy
• Females: Average 82yrs
Highest
Lowest
86yrs Kensington, Chelsea, E.Dorset
70yrs Glasgow
• Males:
Highest
Lowest
Average 77yrs
81yrs Kensington, Chelsea, E.Dorset
65yrs Glasgow
• 75% of females will be alive after the age of 75
• 50% of males will be alive after the age of 75
28% Cancer
6
37% CVD
24% Cancer
36% CVD
Lifespan v ‘Healthspan’
Expected Lifespan:
Men
77yrs
Women
82yrs
Expected ‘Healthspan’:
67yrs
72yrs
ADD Life to years… not years to life
100% value
sedentary
Aerobic Fitness & Ageing
• Decrease in cardiac function: e.g.
 HR = 220-Age
 Cardiac Output
 Stroke Volume
• Decrease in Circulatory capacity: e.g.
 Increase in peripheral resistance
 Less blood flow to active muscle
• Decrease in muscle O2 uptake: e.g.
 Reduced a-vO2 diff
 Reduction in mitochondria & oxidative
enzymes
• Reduced Respiratory function
 (FVC, FEV, RV, MaxVe-1)
VO2Max decreases by 10% per decade
after 25-30yrs
HOWEVER……
Fit 60yr old fitter than
sedentary 20-30yr olds!
Aerobic Fitness, Ageing &
Longevity
• Low aerobic fitness is more important precursor of
all-cause mortality than any of the other risk factors
Aerobic Fitness, Ageing &
Longevity
* Least fit x2 as likely to die prematurely from all causes
* Reduced lifespan and healthspan
Strength & Ageing
• Max muscle strength is achieved
between 25-35yrs
• Strength decreases around 10% per
decade after 25-30
• Primary cause ‘sarcopenia’:
 50% reduction in Motor Units 2580yrs
 Loss of muscle mass
 Loss of Total muscle fibres
 Reduced muscle X-section
 Loss of Fast twitch fibres
 Reduced CNS responses
However, large individual variations –
some stronger at 60 than many at 30.
Strength & Ageing
Resistance training can markedly improve
strength in both males and females at all ages
Improvements in strength of 50-70yr olds males
following resistance training.
Many 60yr olds were stronger than 30yr olds
Ageing & Flexibility
• Decrease in passive and active range of
movement
• Shortened muscles
• Weaker ligaments, tendons, joint capsule
• Increased likelihood of injury
• Decrease in kinaesthetic awareness
Ageing & Body Composition
• Gradual gain in body weight from 20-70yrs
• Decrease in muscle
• Increase in fat (subcutaneous, depot, intramuscular &
essential)
• Decrease in bone mass (e.g. mineral density)
Hazardous Waste
Hazardous Waist
Advancing age – spreading waistline - reduced fitness –
Metabolic Syndrome
A cluster of CV risk factors
-
insulin resistance
hyperinsulinaemia
impaired glucose tolerance or diabetes
raised triglycerides
raised LDLs
decreased HDLs
“Diabesity”
When insulin is bound to
the insulin receptor of
the cell, glucose can be
transported into the cell
and be used.
Normal
Type 2 Diabetes
• Insulin receptors not
functioning
• Insulin cannot bind
• Glucose cannot be
transported into the
cells
Around 90% of all diabetics are Type 2
Benefits of Exercise for Diabetes
• Improve
insulin
sensitivity
• Improve
glycaemic
control
Possible Effects of Ageing
on Firefighters
Typical aerobic cost of fire fighting = 35mlsO2/kg/min
To be working at 80-85% of maximum, aerobic capacity
needs to be at least 42mlsO2/kg/min
Proposed minimum aerobic fitness standard = 42mlsO2/kg/min
Firefit Steering Group (2007).
Norms for Aerobic Capacity (mlsO2/kg/min)
Males
Age Group
Fitness Rating
15-19
20-29
30-39
40-49
50+
60+
55+
50+
46+
44+
Good
48-59
44-54
39-49
37-45
35-43
Average
39-47
35-43
32-38
30-36
27-34
Below Average
30-38
28-34
22-31
24-29
22-26
<30
<28
<26
<24
<22
Excellent
Poor
Females
Age Group
Fitness Rating
15-19
20-29
30-39
40-49
50+
Excellent
55+
50+
46+
43+
41+
Good
44-54
39-49
35-45
34-42
33-40
Average
36-43
32-38
29-34
27-33
26-32
Below Average
29-35
27-31
24-28
22-26
20-25
Poor
<29
<27
<24
<22
<20
Sykes 1996
100%HRMax
85%HRMax
Intense physical activity is a strong triggering factor for
heart attack, especially among physically inactive,
older and unfit individuals.
Heat Stress Tolerance & Ageing
• Reduced thermal tolerance
• Reduced sweat production – less heat lost
by evaporation
• More susceptible to fatal heat injuries
Ageing & Balance
• Good balance important for operational firefighters • Working on roofs, smoky places, slippery surfaces while
wearing PPE & BA
• Wearing PPE & BA affects functional balance in older
compared to younger firefighters (BA was more a sig.
factor).
• Postural balance (with eyes closed) was more negatively
affected among the older subjects than the younger ones.
Dynamic (Functional) & Static (Postural Sway) Balance
- general decrease with ageing
Punakallio et al (2003)
An Integrated Workplace Health & Fitness Programme
for Operational & Civilian Staff
….. OH, FBU, HR, H&S and Welfare …..
Workplace Health & Fitness Programme
• Systematic reduction in sickness rates
& injury
• Systematic improvements in BP, BW,
BMI, Waist, Lipids, Fitness
Ageing and Firefighter Fitness
• Aerobic Endurance
• Strength
• Local Muscle Endurance
Flexibility
• Agility & Balance
• Body Composition
• Metabolic Fitness - Insulin
sensitivity, glucose tolerance, normal BP, hearthealthy blood lipid profiles & fat-burn capability
Ageing & Operational Firefighting
• Age is a poor predictor of job performance among operational
firefighters
• Physical fitness and mental abilities showed the strongest
relationship with job performance
• These vary greatly across individuals regardless of age
• Increase in MSDs
• Fit note or Sick Note ?
• Gender issues ?
• Importance of Physical Fitness
Trainability & Age
Exercise training
improves
physiological
responses and
fitness levels at
any age.
37yrs
Bill Pearl
59yrs
Extracurricular Coronary
Firefit Conference 2008
‘Fit for Service, Fit for the Future’
Physiology of Ageing
- and possible effects on firefighters
Physical Fitness for Firefighting
Kevin Sykes
Professor of Occupational Health & Fitness
Director
Centre for Exercise & Nutrition Science
University of Chester
k.sykes@chester.ac.uk