Exercise: what the experts say Darwin Deen, MD, MS AECOM Aug. 2002.
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Transcript of Exercise: what the experts say Darwin Deen, MD, MS AECOM Aug. 2002.
Exercise: what the experts say
Darwin Deen, MD, MS
AECOM
Aug. 2002
This presentation and all of Dr. Deen’s PowerPoint presentations can be found at:
http://www.aecom.yu.edu/family/ugdeenpresents.htm
Healthy People 2010 lists Physical Activity as a Leading Health Indicator
Exercise and Health
In spite of the known health benefits of exercise (reduction in all-cause mortality, CVD, DM, colon CA, depression & anxiety), less than half of adolescents and young adults engage in regular vigorous exercise.
Exercise and Health
All-cause mortality is reduced up to 40% by an increase in weekly energy expenditure from 500 kcal to 2000 kcal.
In 1999 65% of adolescents engaged in the recommended amount of physical activity. The 2010 goal is 85%.
In 1997 only 15% of adults performed the recommended amount of physical activity. 40% reported no leisure-time physical activity. The 2010 goal for adults is 30%.
Healthy People 2010
What is “recommended”? For adolescents: vigorous physical activity
that promotes cardiorespiratory fitness 3 or more days per week for 20 or more minutes per occasion.
For adults: regular (preferably daily), moderate physical activity for at least 30 minutes.
Exercise and Chronic Disease
Evidence-based Guidelines
Joint National Committee VI
Regular aerobic physical activity—adequate to achieve at least a moderate level of physical fitness— can enhance weight loss and functional health status and reduce the risk for cardiovascular disease and all-cause mortality.
When compared with their more active and fit peers, sedentary individuals with normal blood pressure have a 20- to 50-percent increased risk of developing hypertension.
Joint National Committee VI
Blood pressure can be lowered with moderately intense physical activity (40 to 60 percent of maximum oxygen consumption), such as 30 to 45 minutes of brisk walking most days of the week.
Most people can safely increase their level of physical activity without an extensive medical evaluation.
Patients with cardiac or other serious health problems need a more thorough evaluation, often including a cardiac stress test, and may need referral to a specialist or medically supervised exercise program.
NCEP - ATP III
Physical inactivity is a major risk factor for CHD. Increased emphasis on regular physical activity. Has clear benefits for the management of the
metabolic syndrome. The purposes of regular exercise are:
to promote energy balance to maintain healthy body weight,
to alleviate the metabolic syndrome, and to independently reduce baseline risk for CHD.
NIH Consensus Conference: Guidelines for the Evaluation and Treatment of Obesity
Evidence Statement:
Physical activity, i.e., aerobic exercise, in overweight and obese adults results in modest weight loss independent of the effect of caloric reduction through diet.
Evidence Category A.
NIH Consensus Conference: Guidelines for the Evaluation and Treatment of Obesity
Evidence Statement:
Physical activity in overweight and obese adults modestly reduces abdominal fat.
Evidence Category B.
NIH Consensus Conference: Guidelines for the Evaluation and Treatment of Obesity
Evidence Statement:
Physical activity in overweight and obese adults increases cardio-respiratory fitness independent of weight loss.
Evidence Category A.
USPSTF:Guide to Clinical Preventive Services
Being sedentary doubles CVD risk and getting active results in a 41% decrease in mortality (smoking cessation causes a 44% reduction).
The risk of HT is also half in those who exercise and the risk of weight gain leading to obesity is less.
There is a 6% decrease in the risk of Type II DM for each 500 cal expended per week.
Exercise is associated with less osteoporosis risk and improved mental health.
Moderate physical activity is that which can be sustained for an hour. Vigorous physical activity results in exhaustion after 30 minutes.
Metabolic Equivalents
Caloric expenditure during exercise is expressed as METs (multiples of REE).
Shooting baskets only 4.5.
Baseball & recreational football ~5.
A 70 kg person would burn ~6 kcal/min in a 5 MET activity.
Biking 4-10 METS*
Walking 3.5-6
Running 8-13
Basketball ~8
Swimming ~8
Tennis ~8
ranges depend upon speed
Examples of Sedentary and Active Energy Expendituresfor Common Activities
SEDENTARY kcal ACTIVE kcal
Using remote control device
to change television channel
<1 Getting up and
changing channel
3
Reclining for 30 min
of phone calls
4 Standing for 3 10-min
phone calls
20
Using garage door opener <1 Raising garage door 2x/d 2-3
Hiring someone to
clean and iron
0 Ironing and vacuuming
each for 30 min
152
Waiting 30 min
for pizza delivery
15 Cooking for 30 min 25
Examples of Sedentary and Active Energy Expendituresfor Common Activities
SEDENTARY kcal ACTIVE kcal
Buying pre-sliced vegetables 0 Washing, slicing, chopping vegetables for 15 min
10-13
Using a leaf blower
for 30 min
100 Raking leaves for 30 min 150
Using a lawn service 0 Gardening and mowing
each for 30 min/wk
360
Using car wash 1x/mo 18 Washing and waxing
car, 1 h/mo
300
Letting dog out
the back door
2 Walking dog for 30 min 125
Examples of Sedentary and Active Energy Expendituresfor Common Activities
SEDENTARY kcal ACTIVE kcal
Riding escalator 3x 2 Climbing 1 flight of stairs, 3x/wk in mall
15
Shopping online 1 h 30 Shopping at mall,
walking 1 h
145-240
Sitting in car at
drive-in window, 30 min
15 Parking and walking inside, 3x/wk, total of 30 min
70
Paying at the pump 0.6 Walking into station
to pay, 1x/wk
5
Sitting and listening
to lecture, 60 min
30 Giving lecture 70
Anaerobic vs. Aerobic
Anaerobic
Glucose -> Pyruvate
Aerobic
Pyruvate -> CO2 + H2O
Muscle Metabolism
Lipids are the preferred fuel for muscle cells at up to 25% of maximum work.
At 65%, glycogen is burned preferentially. At high intensities, the longer the duration
of exercise, the greater proportion of fat is metabolized.
With training, muscle burns relatively more fat and less CHO.
Distribution of carbohydrate energy in an average 80-kg person
Muscle Glycogen
Liver Glycogen
Plasma Glucose
Distribution of fat energy in an average 80-kg person
Adipose Tissue
Intramuscular TG
Plasma TG
Plasma FFA
The Exercise Prescription
Type of exercise Resistance exercise to improve strength Aerobic training to improve aerobic capacity
Frequency: 3-5 days/week Intensity: 60-85% of maximal oxygen
consumption (maximal heart rate =220-age)
Duration: 20-60 min
Physical Activity Counseling
Little or no desire to engage in additional physical activity
“I know I should exercise but right now I have too much going on to even think about it.”
Explain the benefits, specific to the individual.
Encourage patient to express their reservations.
Precontemplation
Physical Activity Counseling
“I’ve never been very athletic, and at this stage of my life, it does not seem like a good time to begin.”
Define how much activity they need for health benefits.
Give clear advice r.e. how important it is.
Precontemplation
Physical Activity Counseling
Patients understand the benefits but lack the skills, support, or confidence to initiate action.
Practice active and reflective listening.
Use information provided by the patient to motivate.
Contemplation
Physical Activity Counseling
“I want to, I just haven’t gotten started.”
Explain how the patient can work exercise into their daily routine.
Help the patient develop a specific plan with realistic goals.
Contemplation