AGING AND EXERCISE

1
AGING AND EXERCISE
2
Major Questions
w What is the effect of aging and training on
body composition?
w How are changes in strength and endurance
affected by aging?
w What changes occur to muscles with aging?
w How does training affect biological aging and
What is the difference between aging and physical
activity?
w What cardiovascular and respiratory changes
occur with aging and What is the effect of
training on these changes?
w What is the trainability of older athletes for
strength and endurance?
3
Overview

• Biology of Aging Major Theories
• Scope and nature of the problem of muscle loss
• Causes and Treatment of Sarcopenia
• Recent Studies
• Relation to Major Theories

4
Disease Aging ActivityCV, muscle, bone, brain
5
Biology of Aging Why do we age?

• Cumulative Damage (Environment)
• Inherited (Genetic, passive or programmed)
• Gene x Environment interaction

6
Biology of AgingSpecific Mechanisms

• Cellular damage
• Free-Radical hypothesis
• Oxidative stress
• Mitochondrial Mutation
• Somatic mutation
• Lipid peroxidation
• Glycation
• Random vs. environment
• Genetic Variation protecting

7
Biology of AgingSpecific Mechanisms

• Cellular Repair
• Replication senescence (Telomeres)
• Hormones
• Apoptosis
• Genetic Variation modified

8
Biology of AgingSpecific Mechanisms

• Calorie Restriction
• Replication senescence (Telomeres)
• Metabolic potential, Heart rate limit
• Reduced environment exposure to mutagens
• Genetic Variation modified

9
Biology of AgingSpecific Mechanisms

• Variation in Lifespan between species
• Species protected from predation tend to have
  longer maximal lifespans
• Perhaps grandparents role in survival of
  grandchildren has enhanced selection of
  longevity genes (Active selection)
• Studies of the genetic contribution to longevity
  in humans are confounded by the unanswerable
  question of whether a person is genetically
  predisposed or just dodged a lot of bullets
• The bottom line is that our genes are selected
  based upon reproductive success and not our
  ability to resist the effects of aging

10
Of Mice and Men Voluntary Wheel Running in
Rats
One of the most difficult things to determine is
whether physiological deterioration with age is
due to aging per se or to the dramatic decrease
in daily activity levels. It is undoubtedly a
combination of the two.
11
Body Composition and Aging A Double Whammy
12
CHANGES IN BODY HEIGHT AND WEIGHT
13
CHANGES IN MUSCLE MASS
14
(No Transcript)
15
TOTAL WEIGHT AND RELATIVE FAT
16
FAT MASS AND FAT-FREE MASS
17
Body Composition and Training
One of the important things about physical
training as one ages is that it can help offset
age-related loss of fat-free mass and gains in
fat mass, i.e., the double whammy.
18
Strength Changes With Aging
w Maximal strength decreases
w Muscle mass decreases
w Percentage of ST muscle fibers increases
because of death of fast twitch alpha-motoneurons
followed by reinnervation of the denervated fast
muscle fibers by slow motoneurons, which converts
the muscle fibers to ST
w Total number and size of muscle fibers decreases
w Nervous system response slows
w Little change in oxidative enzyme capacity or
number of capillaries
19
CHANGES IN STRENGTH WITH AGING
20
Number of motor units declines during aging -
extensor digitorum brevis muscle of human beings
AGE-ASSOCIATED ATROPHY DUE TO BOTH Individual
fiber atrophy (which may be at least partially
preventable and reversible through exercise).
Loss of fibers (which as yet appears
irreversible).
Campbell et al., (1973) J Neurol Neurosurg Psych
3674-182.
21
Motor unit remodeling with aging
Central nervous system
Muscle
Motor neuron loss
AGING

• Fewer motor units
• More fibers/motor unit

22
(No Transcript)
23
(No Transcript)
24
Effects of Training on Strength
While endurance training does not prevent the
aging loss in muscle mass, resistance training
can maintain or increase the muscle fiber
cross-sectional area in older men and women.
25
Computed Tomography Scans of Arms of Three
57-Year-Old Men of Similar Body Weights
Biceps Brachii M.
Humerus
Triceps Brachii M.
Untrained Swim-Trained
Strength-Trained
26
MUSCLE FIBER CHANGES WITH AGING
27
Cardiovascular Function and Aging
w Aerobic capacity decreases about 1 per year
after age 25
w Maximum heart rate decreases about 1 beat per
year
w Maximum stroke volume decreases, though it can
be well maintained with training
w Maximum cardiac output decreases
28
Maximal HR and Age
Maximal heart rate can be estimated with the
following equation
HRmax 208 0.7 ? age
29
LEG BLOOD FLOW DURING CYCLING
Thus, the older athletes maintain oxygen
consumption during increasing levels of exercise
by increasing a-vO2diff to a greater extent than
the younger athletes.
30
Cardiovascular Changes With Aging
w HRmax decreases due to decreased sympathetic
nervous system activity and changes in cardiac
conduction.
w SVmax decreases primarily due to increased
total peripheral resistance (increased afterload).
31
Respiratory Changes With Aging
w Vital capacity (VC) and forced expiratory
volume in 1 s (FEV1.0) decrease linearly with age
w Residual volume (RV) increases
w Total lung capacity (TLC) remains unchanged
w RVTLC increases (less air can be exchanged)
w Elasticity in lung tissue and chest walls
decreases, which is the primary mechanism for the
above listed changes there may also be a
decreased function of the respiratory muscles
32
MAXIMAL EXPIRATORY VENTILATION
33
Respiratory Aging and Performance
w Endurance training in middle and older age
reduces the loss of elasticity from the lungs.
w The pulmonary ventilation capabilities of
endurance-trained athletes are only slightly
decreased with aging.
w Arterial oxygen saturation does not decrease
during strenuous exercise for normally active
older adults.
34
Studies of Older Athletes
w There are individual differences in the rate of
decline with aging.
w Prior training offers little advantage to
endurance capacity later in life unless you stay
active.
35
(No Transcript)
36
Changes in Aerobic Capacity and Maximal Heart
Rates With Aging in a Group of 10 Highly Trained
Masters Distance Runners
37
(No Transcript)
38
Aging versus Inactivity
39
Trainability of the Older Athlete
40
CHANGES WITH AGE IN RUNNING RECORDS
41
(No Transcript)
42
(No Transcript)
43
(No Transcript)
44
(No Transcript)
45
(No Transcript)
46
(No Transcript)
47
CHANGES WITH AGE IN SWIMMING RECORDS
48
Swimming Performances at Age 20 and 50 Years for
a Male Masters Swimmer
49
CHANGES WITH AGE IN POWERLIFTING RECORDS
U.S. National Masters records for males for total
(bench, squat, and deadlift) weight class(es)?
50
Sport Performance and Aging
w Running, swimming, cycling, and weight-lifting
records indicate that we are in our prime during
our 20s and early 30s.
w Some swimmers have seen their best swimming
performances in their 40s and 50s this is often
attributed to improvements in swimming technique,
skill, and endurance.
w Performance generally declines with aging
beyond our prime, primarily due to decrements in
muscular and cardiovascular endurance and
strength.
51
Environmental Stress and Aging
w The capacity to perform normal activity at high
altitude is not reduced with aging.
w Aging might provide some protection against the
symptoms of acute altitude sickness, HAPE, and
HACE.
w The ability to adapt to exercise in the heat is
reduced due to reduced sweat production with
aging.
52
Aging versus Inactivity
Since physical activity tends to decline
substantially as we age, distinguishing between
the effects of aging and those of reduced
physical activity is difficult when studying
lifelong changes in physiological function.