KNPE 255 Chapter Notes - Chapter 1-25: Stress Fracture, Diabetic Nephropathy, Epiphysis
Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a
Clinical Vital Sign
• Mounting evidence has firmly established that low levels of cardiorespiratory fitness (CRF) are
associated with a high risk of cardiovascular disease, all-cause mortality, and mortality rates
attributable to various cancers.
• Risk Factors: Smoking, hypertension, high cholesterol, and type 2 diabetes.
• CRF reflects the integrated ability to transport oxygen from the atmosphere to the
mitochondria to perform physical work.
o Can be measured directly as VO2 max or peak work rate.
• CRF is a strong predictor of mortality as established risk factors such as cigarette smoking,
hypertension, high cholesterol, and T2DM.
o >5 METs in adults is high risk of mortality; >8-10 METs are associated with increased
survival.
• Efforts to improve CRF should be a standard part of clinical encounters (e.g., an accepted "vital
sign").
• CFR strongly predicts outcomes across a wide spectrum of CVD outcomes, including those
related to stroke, HF, and surgery.
• Optimizing CRF prior to surgical interventions improves outcomes including surgical risk,
mortality, and function in the postsurgical period.
• The addition of CRF to traditional risk factors significantly improves reclassification of risk for
adverse health outcomes.
• Traditional risk scores (such as Framingham risk score) are enhanced by adding CRF.
• CRF is a variable that is responsive to therapy, and serial measures of CRF are valuable in risk
stratification. Individuals whose CRF increases between examinations have a lower risk of
adverse health and clinical outcomes than those whose CRF decreases, and this should be
communicated to patients.
• Higher levels of CRF are associated with a reduced risk of adverse health outcomes and
chronic diseases in addition to CVD.
• A disproportionately high reduction in adverse health outcomes and cardiovascular risk factors
occurs between the least fit and the next least fit cohorts.
• Physical activity interventions targeting the least fit individuals will likely have the largest
benefit.
• CPX combines conventional exercise testing procedures with ventilatory expired gas analysis,
which allows for the concomitant assessment of 3 prognostic/functional parameters.
o CPX, especially peak VO2, represents the "gold standard" for assessing exercise capacity;
other parameters, including the VE/VCO2 slope, have become primary clinical measures
in many patient subsets, including those with HF, pulmonary arterial hypertension, and
lung disease.
o Although CPX involves higher levels of training and proficiency, as well as equipment and
costs, for many patients the independent and additive information obtained justifies its
use.
o The use of CPX for direct determination of CRF has become more feasible.
o Though not readily available, and CRF can be estimated based on the attained treadmill
speed, grade, and duration of ergometer workload, expressed as watts, from
standardized protocols.
o Shouldn't hold handrails.
o Care should be taken to select a protocol that optimally matches a person's exercise or
functional capacity.
• Other performance tests, including submaximal exercise protocols and the 6MWT, can provide
valuable information in clinical practice and should be considered when resources are limited.
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However, these assessments are not as precise as peak or symptom-limited exercise testing in
quantitating CRF.
• While avoiding the cots and the modest risk associated with exercise testing, non-exercise
algorithms using readily available clinical variables may provide reasonably accurate estimates
of CRF.
o Non-exercise estimated CRF should not be viewed as an alternative for objective
assessment of CRF, especially in some at-risk patient populations.
• Non-exercise estimates of CRF may be useful to provide an initial estimate of one's
CRF, particularly to identify those at increased risk of CVD because of low CRF.
• In most clinical patient subsets, non-exercise estimated CRF should not be viewed
as a replacement for objective assessment of CRF.
• Age and sex significantly impact average CRF levels and should be considered when using CRF
in clinical situations.
• Multiyear studies need to be conducted to better delineate the changes in the biological
mechanisms by which sedentary behaviour and exercise alter CRF.
• Habitual endurance-type exercise produces a variety of biological adaptations that lead to an
increase in peak/maximal CRF, primarily because of an increase in stroke volume and a
decrease in venous oxygen content resulting from an increase in O2 extraction from trained
muscle.
• CRF can be increased in most people by regularly performing rhythmic contractions of large
muscle groups continuously for an extended period of time at a moderate or vigorous
intensity or with recovery breaks at a lower intensity if the exercise approaches maximal
effort.
• When performed frequently over weeks or months, a wide variety of endurance-type physical
activity regiments produce clinically significant increases in CRF.
• CRF more responsive to intensity than duration or frequency.
• Need more vigorous exercise if baseline CRF is high.
o Both HIT and MICT regiments can be effective. When total work is constant, HIT may be
better.
o The role of HIT regimens in the reduction of cardiovascular clinical events remains
unclear.
o Although HIT may be as safe as MICT, for patients with CVD, more data are needed.
• You do not need to be super fit to see benefits in CRF as it's most effective with least fit
groups.
Chapter 10 - PA, Fitness, and Cardiac, Vascular, and Pulmonary Morbidities (pgs. 161-172)
• CVD can be coronary heart disease, stroke, hypertension, rheumatic fever, congenital heart
defects, congestive heart failure, and peripheral vascular disease.
• Also lung disease - chronic obstructive pulmonary disease and asthma.
• There is a dose-response relationship between PA level and coronary heart disease risk.
• The influence of PA and fitness on peripheral vascular disease risk has not been thoroughly
examined.
o However, because about 75% of the deaths in individuals with peripheral vascular
disease are caused by coronary heart disease or stroke, and because physical inactivity
and low fitness are risk factors for coronary heart disease and stroke, it is reasonable to
assume that physical inactivity and low fitness are also risk factors for peripheral
vascular disease.
• Cardiorespiratory fitness level is a stronger predictor of cardiovascular disease than is PA level.
This is explained by the greater degree of measurement error for PA.
• Individuals with cardiovascular and lung disease often have many illnesses, diseases,
functional problems, and psychosocial issues. Thus, PA programs for these patients need to
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focus on improving overall health and well-being and not merely the symptoms of the specific
disease.
Chapter 2- Historical Perspectives on Physical Activity, Fitness, and Health (pgs. 21-36)
• The idea that physical activity enhanced health has been around for thousands of years, e.g.,
yoga.
• Greeks, e.g., Hippocrates stressed the urgency of physical activity.
o Father of preventative medicine.
o Galen also thought that PA could treat basically all diseases and could be used by
virtually all people.
• Scientific evidence for this didn't really come until the 20th century.
• Greek knowledge faded during middle ages but came back around the Renaissance period.
• Italian physicians prescribed it for healthy development for children during the 1500s.
• In 1700s, Ramazzini found negative health effects in certain occupations and how there aren't
many health problems in runners.
o "Diseases of Workers".
• One of the first exercise physiologists - R. Tait McKenzie looked at PA on the body before and
after sport participation.
• Harvard Fatigue Laboratory was one of the first exercise laboratories.
• More of the early physiologists looked more at performance than health benefits.
• London Bus Study was one of the first important studies for epidemiology and PA.
• Dr. Ralph Paffenbarger did a lot of work on long-term epidemiological studies focusing on the
relationship between physical activity and outcomes such as death attributable to
cardiovascular disease.
• W.A. Guy noted the superior health of men in active occupations.
• Collectively, the epidemiology studies have demonstrated that achieving and maintaining at
least a moderate level of physical fitness provide very important health benefits, including
reduced risk of death attributable to cardiovascular disease, and increased longevity.
o Important because showed it at the population level.
• Paul Dudley White important for clinical science as he prescribed exercise for patients with
coronary heart disease.
• Claude Bouchard has been a pioneer in the application of genetics to the study of human
responses and adaptations to exercise.
o Identical vs. fraternal twins.
o Heritage family study.
• Marti Karvonen was important for exercise guidelines.
o The investigation of the HR level needed to produce an increase in cardiorespiratory
fitness set the stage for the development of PA guidelines.
• American College of Sports Medicine (ACSM) guidelines.
o Updated more recently to include more moderate exercise.
• AHA helped make PA be seen as a risk factor for CVD.
o Same with sedentary behaviour.
• CDC-ACSM recommendation was seen as controversial initially.
o 30 mins of PA a day.
o Though, later, some panels agreed that many people require more than 30 mins of daily
PA to prevent excessive weight gain and that more PA is needed to induce and maintain
weight loss in formerly obese individuals than is needed to prevent excessive weight
gain in the first place.
Improved Reclassification of Mortality Risk by Assessment of PA in Patients Referred for Exercise
Testing
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Document Summary
Importance of assessing cardiorespiratory fitness in clinical practice: a case for fitness as a. Crf, particularly to identify those at increased risk of cvd because of low crf. Chapter 10 - pa, fitness, and cardiac, vascular, and pulmonary morbidities (pgs. This is explained by the greater degree of measurement error for pa. Individuals with cardiovascular and lung disease often have many illnesses, diseases, functional problems, and psychosocial issues. Thus, pa programs for these patients need to focus on improving overall health and well-being and not merely the symptoms of the specific disease. Chapter 2- historical perspectives on physical activity, fitness, and health (pgs. Scientific evidence for this didn"t really come until the 20th century: greek knowledge faded during middle ages but came back around the renaissance period. Italian physicians prescribed it for healthy development for children during the 1500s. In 1700s, ramazzini found negative health effects in certain occupations and how there aren"t many health problems in runners.
