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Rehabilitation Medicine
Cardiopulmonary Exercise in the Aging Adult
Matthew N. Bartels, MD, MPH
Professor and Chairman of Rehabilitation Medicine Albert Einstein College of Medicine
Chairman, Department of Rehabilitation Medicine Montefiore Medical Center
Declarations/Disclosures
Unfortunately no Conflicts of Interest
–Working on that……
No off label uses of medications or devices
Objectives
Effects of aging on cardiopulmonary exercise capacity Review the basics of exercise physiology Beneficial effects of aerobic and strengthening exercise on
cardiovascular physiology in older individuals
Bad News and Good News with Aging
Bad News–Capacity declines as you age
Good News–You can do something about it–Fatigue and immobility are not inevitable parts
of aging–Fitness isn’t all that hard to achieve
The Bad News About Aerobic Exercise with Aging
Bad News 1: Muscle function changes with age– Strength decreases due to loss of muscle mass.– Fiber type switching to type II x– Increased fibrous tissue in muscle
Bad News 2: cardiovascular function change with age
–Maximum heart rate decreases with age (MHR = 220 – age)
–Resting cardiac output declines about 1%/year during adulthood
–Coronary artery disease is more common
–Blood flow during exercise is less
–Maximum exercise declines gradually with age
Bad News 3: Pulmonary Function Changes with Age
Lung capacity declines
Chest wall is stiffer (less compliance)
Decreased oxygen absorbtion (lower DLCO)
Breathing becomes less efficient with age
Loss of lung with aging (1% per year)
Bad News 4: Aging Alters Body Composition
Body Composition Increased Fatty Tissue
Decreased Lean Mass
Stature We grow shorter as we get older by about one-half
inch per decade after age 30.
Bad News 5: Multiple factors may explain the changes in functional capacities with age
True aging phenomena
Unrecognized disease processes
Disuse phenomena
Deconditioning
Medications
Assessment of Demands of Exercise Activities
Usually used for dynamic exercise
Typically described in terms of metabolic equivalents
–1 MET = 3.5 ml O2/Kg weight/min
Use of standardized MET tables can help assess independence AND GOALS
Oxygen Consumption with Exercise
Relationship of Dynamic Exercise and Oxygen Uptake
Heart Disease
Limits on O2 ConsumptionStroke Volume–End Systolic Volume–End Diastolic Volume–Effected by position
Reduced in Cardiac Disease–Myocardial Infarction–Heart Failure
Muscle mass decreasedNeurologic dysfunction
Limits on O2 Consumption: Blood
Arterial Oxygen carrying capacity–Increased with exercise–Increased with increased Hemoglobin
Increased CaO2 - CvO2
–Mostly due to decreased CvO2
–Increased Peripheral extraction Shunting of increased Output to active tissues This is where blood doping in professional sports
comes in! –Autotransfusion, Epo, etc.
Oxygen Carrying CapacityBlood doped!
Tissue Blood Shunting with Exercise
Rest Blood Flow (mL)
% Blood Flow
Exercise Blood Flow (mL)
% Blood Flow
Muscle 1,000 20.0% 21,000 84.0%
Heart 200 4.0% 1,000 4.0%
Liver 1,350 27.0% 500 2.0%
Kidneys 1,100 22.0% 250 1.0%
Brain 700 14.0% 900 3.6%
Skin 300 6.0% 600 2.4%
Other 350 7.0% 750 3.0%Total Blood
Flow 5,000 25,000
Effects of Dynamic Exercise on Blood Pressure
Minimal change in Diastolic BP–May actually drop a little
Marked Rise in a linear fashion in SBP–Does not usually rise above 200 mmHg
Moderate rise in Mean BPBP increase due to increased CO, not increased
peripheral resistance.Effects are about 10% higher for arm exercise
than leg exercise.
Effects of Dynamic Exercise on Blood Pressure
Response to Isometric Exercise This is not safe type of exercise for Cardiac Patients! Lower metabolic demand for a given activity Marked increases in SBP, DBP, MBP
– Can easily exceed 220/110 mmHg (SBP/DBP) Marked heart rate increase
– Out of proportion to the metabolic demand of the activity SV lowered with activity, rebounds with relaxation Cardiovascular steady state not achieved Muscle blood flow decreased during >40%
contraction, increased at <30% contraction
Blood Pressure Responses to Isometric Exercise
Effects of Inactivity on ExerciseDecreased VO2
Increased resting heart rate, blood pressureDecreased stroke volume at rest and with
exercise–Possibly due to decreased venous return
Have alterations in red blood cells, less red cellsDecreased responsiveness in muscle vascular
beds – higher blood pressure!
Inactivity and Exercise Capacity
Good News 1: There are Benefits to Aerobic Exercise
Improved sense of well being
Weight control
Decreased fatigue
Improved immunity
Decreased bone/lean body mass loss
Decreased cardiac disease
Decreased decline in function
Good News 2: These benefits of exercise come about in many ways
Improved efficiency– Increased cardiac function– Improved circulation– Improved muscle function– Improved neural control of
function– Increased lean body mass– Improved basal metabolic
function
Good News 3: Improved Heart Function
Improved cardiac output– Increased stroke volume
Decreased resting heart rate– Decreased anginal symptoms
– Decreased work of the heart
Decreased systemic blood pressure– Less resistance for cardiac work
Good News 4: Improved Circulation
Decreased arterial resistance
Decreased blood pressure
Improved capillary function
–Decreased diastolic blood pressure
–Improved delivery of oxygen to the peripheral tissues
Improved muscle tone in the blood vessel walls
Good News 5: Improved Muscle Function
Improved muscular circulation
Improved capacity to aerobically metabolize and perform work
Increased mitochondria (muscle power generation)
Increased muscle fiber density
Good News 6: Increased Lean Body Mass
Increase in muscle tissue Decrease in fatty tissue Improved metabolism–Increase use of fat–Decreased storage of fat
Helps with weight maintenance Decreased appetite–Moderate exercise decreases appetite
SURPRISE! Aerobic Exercise is Reasonably Easy to Do
Even Moderate daily activities are helpful– Brisk walking
– Gardening
– Yard work
– Housework
– Climbing stairs
– Active recreational pursuits
Principles of aerobic training for a healthy older adult
Mode:– Aerobic activity
Intensity: – An intensity of 55 to 90 percent of maximal heart
rate or 40 to 85 percent of maximum heart rate reserve
Duration: – A duration of 20 to 60 minutes a session (or in 10-
minute bouts accumulated throughout the day) Frequency:
– A frequency of three to five days per week
Estimation of Maximum Heart Rate
Usual Method: Max HR = 220-Age Alternative method (for older ages):
– Max HR = 208 - 0.7(Age) (conventional technique underestimates the peak HR for age.
Example for 40 and 60 year old people– Standard Way: 220 - 40 = 180
220 - 60 = 160– Alternative Way: 208 - 0.7(40) = 180
208 - 0.7(60) = 166
Karvonen Technique
Calculate target heart rate based on intensity HRtarget = HRrest + %(HRmax - HRrest) Example: 30 year old woman to exercise at 80% of capacity after
testing– Resting HR = 75 bpm, Max HR on CPET 185 bpm– HRtarget= 75 + 0.80(185-75) = 163 bpm
Estimate method: HRtarget= 0.80(220-30) = 152 bpm Estimated HR targets usually lower and less accurate. But
preserves safety in situation with no testing.
Caution 1: Recommendations for Developing and Maintaining Fitness
Use large muscle groups Continuous, rhythmical, aerobic
activities Use heart rate guidelines Use Warm-up and Cool-down Assess cardiac risk–Simple history => family history–Unexplained dyspnea
Orthopedic risks
Types of ExerciseDynamic–Aerobic - Cardiac–Conditioning - Cardiac
Static–Anaerobic - Non Cardiac–Strengthening - Non Cardiac
Remember Basic Physiology!
Endurance activity requires more aerobic fibers– This is predominantly Type 1 fibers
Sustain activity for hours, but slow twitch speed and small fiber size
Short burst activity requires more anaerobic fibers– These are predominantly Type 2 fibers subdivided into:
2a moderately fast – long term anaerobic (<30 min) 2x fast – intermediate short term aerobic(<5 min) 2b very fast – short term aerobic (<1 min)
35
Basic Terminology Measurement of exercise capacity–Aerobic Training
VO2 – defined as LO2/minute or mlO2/kg/min MET – one metabolic equivalent - 3.5 mlO2/kg/min Wattage – Resistance on an ergometer – this is power output Heart rate – Used to determine the level of intensity once
power at a given heart rate established RPE – can guide exercise once power rates determined
–Resistance Training Maximum Voluntary contraction – one rep max
36
Basic Exercise for Health
37
Warm-up and Cool-down GuidelinesWhat constitutes an effective warm-up? • Ideally the warm-up should involve low to
moderate intensity exercise that mimics thephysical activity to follow.
• Helps prevent musculoskeletal injuriesBenefits of cooling down after low to moderate activity Helps to clear lactic acid from the blood Prevents blood pooling in the lower extremities, which can
cause dizziness/vasovagal syncope Helps maintain increased muscle and connective tissue
temperature, increasing flexibility
Conclusion Moderate aerobic exercise is very
beneficial and safe in most individuals Even (especially) individuals with
cardiac, pulmonary, or peripheral vascular disease will benefit.
After the age of 40, consider if there are risks prior to high intensity exercise, moderate is always safe
Qualified supervision in disease states– May benefit from specific programs
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