Exercise prescription as defined by Dr. Amer Suleman, as the specific plan of fitness – related activities designed for a specific purpose, which is often developed by a fitness or rehabilitation specialist for the client or patient. Components of exercise prescription generally includes specific recommendations: (1) type of exercise or activity (walking, swimming, cycling) (2) specific workloads (watts, walking speed) (3) duration of activity or exercise session (4) intensity guidelines – target heart rate range (THR) and estimated rate of perceived perception (RPE) and (5) precautions regarding certain orthopedic or other concern related comments. Dr. Suleman further explains that Heart rate reserve (HRR) is defined as the maximal heart rate (HR max) observed during a symptom-limited exercise stress test minus the resting heart rate (HR rest). A percentage of the HRR range is added to the HR rest to determine a THR range to be used during exercise. This approach accounts for individual variability in the HR rest and better reflects the peak exercise oxygen consumption (VO2). Exercise intensity is generally recommended to be 60-90% of the HR max or 50-85% of the VO2 maximum (VO2 max) or HRR. For example, a patient with coronary heart disease on beta-blockade medication has an HR max of 120 beats per minute (bpm) and an HR rest of 55 bpm. The recommended THR would be calculated as follows: (1) HRR = 120 – 55 = 65 (2) THR range = [(HR max - HR rest) X (0.5 - 0.85)] + HR rest (3) THR = 65 X 70% = 46 + 55 = 101 bpm. Thus, the suggested THR range would be 96-108 bpm. The VO2 max is the maximal amount of oxygen that an individual can consume and use during exercise or physical work. This value may be measured or estimated and is expressed commonly in milliliters of oxygen per kilogram of body weight per minute (mL/kg/min).
src=”http://pagead2.googlesyndication.com/pagead/show_ads.js”>
style=”text-align:justify;text-indent:.5in;line-height:200%”>
style=”text-align:justify;text-indent:.5in;line-height:200%”>
style=”text-align:justify;text-indent:.5in;line-height:200%”>
The RPE scale is used widely in
exercise science
and sports medicine to monitor or prescribe levels of exercise intensity. The
95%-limits-of-agreement technique has recently been advocated as a better means
of assessing within-subject (trial-to-trial) agreement. The perception of
exertion is a monitoring behavior that uses all sources of information
to govern
actions that can benefit or preserve health and partake of adaptive pursuits.
How a person feels about exertion moderates his or her response to exercise and
effort. The perception of what is happening in exercise, and its concomitant
effect on physiological function, must be known to further understand
the nature
of an exercise response. How a person feels modifies reactions to exercise
stress and the mechanisms that underlie them. The Borg scale is as follows: (1)
Six – No exertion at all (2) Seven to eight – Extremely light (very,
very light)
(3) Nine to ten – Very light (A1 warm-up / recovery) (4) Eleven – Light (A2
aerobic threshold) (5) Twelve to thirteen – Moderate (EN-1 anaerobic threshold)
(6) Fourteen to fifteen – Hard (EN-2 VO2 max or 400 m swimming pace)
(7) Sixteen to seventeen – Very hard (AN-1 peak lactate or lactate tolerance,
200 m swimming pace) (8) Eighteen to nineteen – Extremely hard (very, very hard
[AN-2 anaerobic power, 25-50 m swimming pace]) (9) Twenty – Maximum all-out
effort with absolutely nothing being held in reserve (1998).
Instructions for use as suggested by Dr. Amer
Suleman:
During the exercise you are to rate
your perception of exertion. Use this scale where 6 mean no exertion at all and
20 means a totally maximum effort. The 13, on the scale is somewhat heavy
exercise but capable of being performed at steady state (i.e., anaerobic
threshold). When at a level of 17, the effort level requires you to push
yourself hard even though it is possible to continue for some time. For many
people 19, is about as strenuous as exercise becomes because they often reserve
a small amount of possible extra effort. Try to appraise the feeling
of exertion
as honestly as possible. Do not underestimate nor overestimate it. It is of no
value to underestimate the level to produce an impression of being
“brave” or
“tough”. Your own feeling of effort and exertion is all that
is of interest.
Look at the scale and wordings and decide on the word that best describes your
effort level and the number alternative associated with that
description.
Considering the different modes of exercise: (1)
Intensity: This should range from low to moderate for healthy individuals. (2)
Duration: Continuous aerobic activity for 20-60 minutes is recommended. (3)
Frequency (3a) Individuals with a less than 3-MET capacity should engage in
multiple short sessions each day. (3b) Individuals with a 3- to 5-MET capacity
should engage in 1-2 sessions per day. (3b) Individuals a greater than 5-MET
capacity should engage in 3-5 sessions per week.
ACC/AHA (American College of
Cardiology / American Heart Association Task Force on Practice
Guidelines) 2002,
Guideline Update for Exercise Testing: The weight of evidence was
ranked highest
(1) if the data were derived from multiple randomized clinical trials that
involved large numbers of patients and intermediate (B) if the data
were derived
from a limited number of randomized trials that involved small numbers of
patients or from careful analyses of non – randomized studies or observational
registries. A lower rank (C) was given when expert consensus was the primary
basis for the recommendation. The ACC/AHA classifications II, III, and I are
used to summarize indications as follow:
Class I: Conditions for
which there is evidence and/or general agreement that a given procedure or
treatment is useful and effective.
Class II: Conditions for
which there is conflicting evidence and/or a divergence of opinion about the
usefulness/efficacy of a procedure or treatment.
Class IIa: Weight of
evidence/opinion is in favor of usefulness/efficacy.
Class IIb:
Usefulness/efficacy is less well established by evidence/opinion.
Class III: Conditions for
which there is evidence and/or general agreement that the
procedure/treatment is
not useful / effective and in some cases may be harmful.
The general context
for the use
of exercise testing is outlined in Figure 1.
src=”new_page_1_files/image002.jpg”
v:shapes=”_x0000_s1025″>
Figure
1.General context of the exercise testing guidelines
Source:
ACC/AHA Task Force on Practice Guidelines
src=”new_page_1_files/image004.jpg”
v:shapes=”_x0000_s1026″>
Figure 2:
Nomogram of the prognostic relations embodied in the treadmill score
Source:
Source: ACC/AHA Task Force on Practice Guidelines
The value of exercise
testing, according to
Bowling, A., Bond, M., McKee, D. et al. is that exercise testing has a
sensitivity of 78% and a specificity of 70% in detecting coronary artery
disease. Hence a negative test does not adequately rule out disease. A positive
test is much more likely to be false in a young person than an older person
unless there is a very good history as they are at much lower risk. Therefore
testing of young, asymptomatic people is controversial. There is a suggestion
that not enough women and the elderly are being tested (2001). Hence, as stated
by
Doctor Paul Hewish style=”font-size:11.0pt;line-height:200%;font-family:Helvetica;color:windowtext”>,
prognostic testing
can be useful. A positive test at a low workload is a poor prognostic sign and
it indicates the need for urgent treatment. Bayes’ theorem of diagnostic
probability states that the predictive value of an abnormal test varies
according to the probability of the disease in the population being study.
Therefore, exercise testing is usually performed in patients with a moderate
probability of coronary artery disease, rather than in those with a very low or
high probability (2004).
Bruce protocol
is very widely used and has been extensively
validated. There are 7 stages of 3 minutes each so that a complete
test takes 21
minutes. The level of exercise is estimated in METs. 1 MET or metabolic
equivalent is the amount of energy expended at rest or 3.5ml oxygen
per kilogram
per minute. At rest, the average person has an oxygen consumption of 1 MET (or
3.5 ml/kg-min). MET values increase as more activity is performed.
In stage 1 the patient walks at 1.7
mph (2.7 km)
up a 10% incline. Energy consumption is estimated to be 4.8 METs during this
stage. The speed and incline increase with each stage. The information from an
ETT can be used to advise the patient on what activities and exercise
levels are
reasonable. An example of an MET chart is as follows:
cellpadding=”0″ style=”border-collapse: collapse; border: medium
none”>
METs
Exercise
Recreational
Occupational
Activities of DL
1.5 – 2.0
Strolling 1 – 1.5 mph, 1 mile in 40 – 60
minutes
Knitting; playing cards; sewing;
watching TV
Desk work; driving auto/truck;
sitting doing
light assembly; typing; using hand tools; writing
Brushing hair / teeth, light housework;
making bed; partial bath; polishing furniture; washing clothes
2.0 – 3.0
Walking, level 2.0 – 2.5 mph, 1 mile in 24-
30 min cycling, level outdoors – 5mph
Horseback riding (walk), light golf (power
cart); playing musical instrument; shuffle board; woodworking
Bartending; crane operation; standing doing
light or medium assembly; TV / auto / car repair; working heavy
lever
Cooking; driving car; ironing; riding lawn
mower; scrubbing floor; walls, cars; widows; showing; sweeping;
tub bath
3.0 – 4.0
Walking 3.0 – 4.0 mph, 1 mile in
15 – 20 min
cycling, outdoors 5.5mph
Billiards; bowling; canoeing; croquet; fly
fishing; golf (pulling cart); shopping; volleyball (non –
competitive)
Baling hay; driving heavy truck; heavy
machine assembly; janitorial work; light welding; operating large levers;
plastering; plumbing; stocking shelves
Cleaning windows; climbing stairs (slowly);
General House work; kneeling; light work; pack/unpacking; power lawn mowing
(light); sexual intercourse; stocking shelves; vacuuming
4.0 – 5.0
Walking 3.5 – 4.0 mph, 1 mile in cycling,
8mph calisthenics swimming (20 yd/min)
Ballet; dancing; gardening (how? Weeding,
digging); golf (carrying clubs); table tennis; tennis (doubles);
volleyball
Building interior of house;
carrying trays /
dishes; farm work (sporadic); house painting, lifting, carrying objects (20
– 40 lb); light carpentry; mechanic work
Raking leaves; shoveling light
loads
5.0 – 6.0
Walking 4.0 – 4.5mph 1 mile in 13 – 15
minutes, biking in 10 mph
Canoeing (4m/hr); gardening (digging);
skating (ice / roller); social / baseball (non- game); stream
fishing
Handyman work (moving, shoveling); heavy
carpentry; putting in sidewalk
Raking leaves; shoveling light
loads
6.0 – 7.0
Walking/jogging,
4.0-5.0 mph
1 mile in 12-13 min
Biking, 11 mph
Swimming (breaststroke)
Backpacking (light); Badminton; Hiking;
Hunting; Horseback riding (trot), Skiing (cross country 2.5 mph); Skiing
(light downhill); quare dancing; Tennis (singles)
Exterior home building; Lifting, carrying
objects (45-64 lb); Shoveling (10/min, 9 lb); Splitting wood
Lawn mowing (push mower); Snow shoveling
(light snow)
7.0 – 8.0
Walking, 5 mph
1 mile in 12 min
Biking (outdoors) 12 mph
Swimming (backstroke), 40 yd/min
Badminton (competitive); Basketball
(non-game); Canoeing (5 mph); golf (carrying bag); Horseback (gallop);
Skiing (downhill, vigorous)
Ascending stairs with 17 lb load; Lifting,
carrying (65-84 lb); Moving heavy furniture; Sawing
8.0 – 9.0
Jog/run 5.5 mph
Biking (outdoors) 13 mph
Swimming (breaststroke) 40 yd/min
Rowing machine; Rope jumping (60-80 skips/min)
Basketball (non-game);
Handball/squash/racquetball; Mountain climbing; Soccer (non-team); Touch
football; Tour skiing
Lifting, carrying (85-100 lb); Moving heavy
furniture (moving van work); Shoveling (14 lb scoops, 10 scoops / min);
Using heavy tools
9.0-10.0
Jog/run, 6 mph
1 mile in 10 min
Football (competitive); sledding /
tobogganing
Heavy labor; Lumberjack; Shoveling (16 lb
scoops)
Ascending stairs carrying 54 lb
11.0+
Run 7 mph (11.5 METs)
8 mph (13.5 METs)
Competitive sports: Basketball, Handball,
Racquet, Rowing
Figure 3: MET chart
Source: University of Iowa: Cardiac
Rehabilitation Guide (2006)
style=”text-align:justify;text-indent:.5in;line-height:200%”>
Patients who are candidates
for exercise testing may have stable symptoms of chest pain, may be stabilized
by medical therapy after symptoms of unstable chest pain, or may be
post-myocardial infarction or postrevascularization patients. Patients who are
unable to exercise or who have uninterpretable ECGs because of pre-excitation,
electronically paced rhythm, left bundle-branch block, or ST depression greater
than 1 mm require imaging studies and are beyond the scope of these guidelines.
Imaging studies are considered in other ACC/AHA guidelines
(5,348-350).
Although some studies suggest an even lower training threshold than
the one used
in the particular study (i.e., < 70% maximal heart rate), especially in
extremely deconditioned subjects, if individuals can regularly attain
a training
intensity of at least 70% maximal heart rate via brisk walking, it is likely
that they will achieve improved aerobic fitness. These findings may be
especially relevant for the inactive patient in whom the subjective discomfort
of vigorous physical training may serve as a deterrent to long-term compliance
with exercise therapy (Anthony, 2002). The ability of exercise training as told
by Wannamethee, S.G., Shaper A.G., & Walker, M. (2000) is to
reduce morbidity
and mortality rates hasn’t been well established for elderly patients, but
limited data suggest some benefit (Table 1).
style=”border-collapse: collapse; border: medium none; margin-left:
5.4pt”>
style=”text-align:center;line-height:200%”>
Intervention
style=”text-align:center;line-height:200%”>
Reduces Mortality
style=”text-align:center;line-height:200%”>
Reduces Morbidity
Control of diabetes mellitus
Yes
Yes
Control of obesity
Not clear
Not clear
Dyslipidemia therapy
Yes
Yes
Exercise
Yes*
Not clear
Hypertension therapy
Yes
Yes
Psychosocial interventions
Not clear
Not clear
Smoking cessation
Yes
Yes
Table 1: Impact of
Interventions on All – Cause Mortality and Cardiovascular Morbidity in Elderly
Patients
Source: American Family
Physician News and Publications (2005)
style=”text-align:justify;text-indent:.5in;line-height:200%”>
In the British Regional Heart Study, which
enrolled men with known CHD (mean age, 63 years), light to moderate physical
activity in the form of regular walking, frequent recreational
activities (e.g.,
gardening), or once-weekly sporting activities (e.g., jogging, swimming), was
associated with a significant reduction in all-cause mortality at five years of
follow-up. More
vigorous types of activities did not show a statistically significant reduction
in that same endpoint (2000). A Cochrane review of men and women of all ages
with previous MI, revascularization or angina found that exercise-only cardiac
rehabilitation reduced all cause mortality by 27%, cardiac death by 31% and a
combined end point of mortality, non fatal myocardial infarction and
revascularization by 19% (2000).
style=”text-align:justify;text-indent:.5in;line-height:200%”>
Prior to initiating an
exercise
program for the post-rehab client, the trainer will need to obtain a health
history form, a signed informed consent, a physician’s referral / release for
exercise
and, if possible, a copy of the client’s rehab records. The physician’s
referral/release form should indicate the trainer’s credentials and state that
no medical monitoring (e.g., blood pressure, ECG, pulse oximetry, etc.) will be
performed. The physician should be asked to provide a training intensity if
age-predicted target heart rate range is not appropriate. A request for
exercise
precautions should also be included (Salge, 2001).
style=”text-align:justify;text-indent:.5in;line-height:200%”>
For most patients, clinical risk stratification
based on history, examination and resting ECG combined with a functional
capacity test such as a shuttle walking test or a six minute walking test will
be sufficient. The test was supervised by a physical therapist and was
performed,if indicated by the physician, using telemetry
monitoring.
Subjectswere asked to walk at their own maximal pace along a 35-m
long,flat, and straight hospital corridor. No encouragement was
offered.The test was symptom limited, so patients were allowed to
stopif signs or symptoms of significant distress occurred
(severe
dyspnea, dizziness, angina, skeletal muscle pain), though they
were instructed to resume walking as soon as possible. The distance
covered during the test was recorded in meters.
The 6MWT has become one of the most popular
clinical exercise tests for evaluating functional capacity. It
is a practical, simple, and inexpensive test, and does not require
any exercise equipment or advanced training for technicians (The American
Thoracic Society, 2004). The shuttle walking test (cited in SIGN
Publication No.
57) is a low cost low tech alternative to exercise testing that informs the
rehabilitation team on a suitable exercise programme and appropriate training
heart rate, and allows assessment of progress during cardiac rehabilitation
without the need for cardiac technicians, physicians or expensive equipment
(2005). The shuttle walking test protocol is given in Box 1.
style=”border-collapse: collapse; border: medium none”>
Shuttle Walking Test
Equipment
required
Calibrated cassette player and shuttle walk
test tape. Two marker cones and non slippery, flat walking surface at least
10 meters in length. Heart rate
monitor with record facility and adjustable upper alarm limits.
style=”font-family:Arial;color:windowtext”>Protocol
Each subject should be screened by a member
of the cardiac rehabilitation team for any exclusion criteria before
proceeding. Place two cones exactly 9 meters apart, thus allowing the
subjects to walk 10 meters when they go round the cone at the end of each
shuttle. Subjects then listen to the
instructions on the audio cassette. These should be repeated verbally to
ensure that they understand what is expected during the test. Subjects walk
around the 10 meter course aiming to be turning at the first marker cone
when the first audio signal is given, and turning at the second cone at the
next audio signal. Subjects
should be
accompanied around the first level of the test to help them keep pace with
the audio signals. Thereafter the operator stands mid way between the two
marker cones offering advice on completion of a level: ‘Walk a
bit faster
now if you can’. Progression to the next level of difficulty is
indicated by a triple bleep which lets the subject know that an increase in
walking speed is required. The full
test comprises 12 levels each of one minute duration with walking speeds
that rise incrementally from 1.2 miles per hour (1.9 km per hour) to 5.3
miles per hour (8.5 km per hour). style=”font-family:Arial”>The
test is completed at 12 minutes or if one of the termination criteria is
met.
Termination
criteria
o
Any anginal symptoms or
feeling too breathless to continue.
o
Feeling dizzy or faint.
o
Leg pain limiting further
exercise.
Achieved level of perceived exertion >=15 (Borg
Scale)
Achieved heart rate >=85% predicted (detected by audible
upper alarm limit). Failure to meet the speed requirements of the test -
subject more than half a meter from the cone when the bleep sounds.
Following
the test
Subjects should continue to walk slowly
around the course a further four times to avoid any syncopal attacks
associated with abrupt cessation of exercise. Subjects are then seated and
asked to confirm their limiting symptom.
Record total distance walked heart rate and
perceived exertion for each level completed, peak heart rate and reason for
test termination. If subjects have
fully recovered after 10 minutes then no further action is
required. If they
report continuing breathlessness or angina then a further rest
period should
follow during which they may receive sublingual nitrates, have an ECG or be
seen by a doctor as appropriate.
Box 1.Shuttle
Walking Test
Source: SIGN Publication No.
57 (2005)
style=”text-align:justify;text-indent:.5in;line-height:200%”>
style=”text-align:justify;text-indent:.5in;line-height:200%”>
Cardiac rehabilitation (Giannuzzi, P. et al.) today targets
people with
ischaemic heart disease, congestive heart failure and people with a
high risk of
developing ischaemic heart disease. The short-term goals of cardiac
rehabilitation are to stabilize heart disease, to limit the physical and mental
effects of heart disease, to improve the functioning of the people with heart
disease and to improve their quality of life. The long-term goals are to reduce
patients’ long-term risk of heart disease, to stop the progression of heart
disease and to reduce morbidity and mortality. According to current evidence,
these goals can best be realized through comprehensive cardiac rehabilitation
programmes based on exercise training, patient education, lifestyle
intervention, risk factor management and clinical assessment, psychosocial
support and optimizing the pharmaceutical treatment of symptoms. Pharmaceutical
treatment comprises an important part of overall rehabilitation
(2003).
Efforts to prevent heart disease can be divided into
primary, secondary
and tertiary prevention.
Primary
prevention
means preventing disease from arising at all.
Secondary
prevention
means identifying patients at high risk of developing ischaemic heart disease
and identifying symptoms and disease at early stages to reduce the course of
disease and contribute to improving the prognosis. Tertiary prevention means
preventing remission of disease and preventing chronic conditions, including
reduced functioning as a result of disease (Kamper, Jørgensen F &
Almind G ,
2003).
In summary, the
finding
of this particular study
suggest that physicians and allied health professionals can prescribe brisk
walking on a flat surface to their
cardiac
patients with confidence that this intensity will achieve cardiorespiratory and
health benefits. Furthermore, these results serve to discount the lingering
notion that
cardiac patients need to participate in vigorous
exercise
such as jogging or running in order to benefit from an
exercise
training program. Phase II
cardiac
rehabilitation
programs are associated with improvements in
exercise
tolerance, coronary risk factors, and psychosocial well-being. Nevertheless,
previous reports have generally evaluated the global effectiveness of these
programs (i.e., on all subjects, collectively), which may serve to
camouflage or
attenuate the impact of these interventions on specific
patient
subsets. In one particular study, the researchers investigated the
effectiveness
of a contemporary,
exercise-based
cardiac
rehabilitation
program that included a cardiovascular risk-reduction intervention, using a
computerized database on 117 patients (average age, 66.5 years; 68% men; 96%
white) who completed pre-phase II and post-phase II evaluations (Gordon, 2002).
As pointed out by, (Dr. Bonnie Sanderson, 2004) cardiac rehabilitation begin
with a patient assessment that helps us develop an individualized,
goal-directed
treatment plan with short-term and long-term objectives for reducing
cardiovascular risk and improving quality of life. Ideally, patients should be
referred to cardiac rehabilitation within 1 month of a coronary event, but they
can begin the program (12 to 36 sessions, depending on individual need) for up
to 1 year after an event. Therefore, there are short term and long term goals
that will benefit the patient in a short term basis and long term basis
depending on the program that was intended for the patient and the
extent of the
disease. Dr. Vera Bittener also added, physicians have an obligation
to strongly
recommend cardiac rehabilitation and reinforce that message in
follow-up visits.
More patients would comply with the recommendation if the message —
that cardiac
rehabilitation increases survival and improves quality of life — were strongly
emphasized (2004).
Credit:ivythesis.typepad.com
0 comments:
Post a Comment