Clinical Exercise Physiology

3 Main Purposes of Exercise Testing

3 Main Purposes of Exercise Testing

Functional- level of fitness Diagnostic- underlying disease Prognostic- evaluating progress after starting an exercise program or determining the likelihood of a positive test

Reasons for Screening

To weigh the indications vs. contraindications Make sure its safe for an individual to be tested and start an exercise program Determine the appropriate exercise test Determine if medical supervision is needed for the individual and type of test

Indications

Reason to exercise test

Contraindications

Reasons not to perform an exercise test

PAR-Q

Physical activity readiness questionnaire Useful for apparently healthy individuals considering an exercise test or program

Medical History

Diagnoses, hospitalizations, medications- dose and frequency, family history, physical activity history

Physical Evaluation

Everyone needs one Auscultation, blood pressure, pulse rate, pulmonary function, resting electrocardiography, EKG

Depolarization- EKG

Exciting heart for contraction

Repolarization- EKG

Returning the heart to resting potential for relaxation

P Wave (EKG)

Artial depolarization Leads to atrial contraction (systole)

CRS Complex (EKG)

Ventricular depolarization Leads to ventricular contraction (systole)

T Wave (EKG)

Ventricular repolarization Leads to ventricular relaxation (diastole) Chemical or mechanical

Informed Consent

Agreement between client and physician concerning the procedures, risks, benefits, and expectations for test/study

Graded Exercise Training (GXT)

Usually conducted on treadmill or cycle Usually lasts 8-15 minutes Maximal or submaximal Increased intensity in stages End point may be related to oxygen consumption, heart rate, blood pressure, subject's feelings Different populations require different end points

Oxygen Consumption

VO2 The amount of oxygen that you take in, transport, and use Relative and Absolute Measured via indirect calorimetry- oxygen removed from air, CO2 added to air Typically described in terms of METs- metabolic equivalents

Relative VO2

Takes into account body size mL O2/kg body weight/min At rest: 3.5 mL/kg/min

Absolute VO2

L O2/min

Relative-> Absolute VO2

3.5 mL/kg/min x body weight in kg / 1000mL

METs-> Relative VO2

__ METs x 3.5 mL/kg/min/1 MET

Absolute-> Relative VO2

(__ L/min x 1000 mL)/__ kg

VO2 Max.

Maximum aerobic capacity Related to endurance Most accepted index of fitness Decreases with age after around 30 Oxygen in- oxygen out Activity level, age, gender

Maximal GXT Protocols

Bruce Protocol Naughton Protocol Balke Protocol

Bruce Protocol

Used for: fit population Starts at 4.5 METs and increases 3 METs per stage Steep hill, 3 min. stages Very reliable and valid results

Naughton Protocol

Used for: older, diseased populations Starts at 2 METs and increases 1 MET per stage Lower speeds than Bruce

Balke Protocol

Used for: older, diseased populations Start at 3.5 METs and increases 0.5 METs per stage

GXT Parameters Measured

Oxygen consumption Heart rate Blood pressure EKG Blood lactate concentration (not typical) Dyspnea Angina Borg rating

Borg Rating

Subject's perceived exertion/difficulty level Range: 6-20 Good test: 18+ rating

Exercise Prescription Goals

Improve health Improve physical capacity Ensure safety

Training Principles

Specificity Overload Progression

10% Rule

increase exercise intensity by no more than 10% each week

FITT- Progression

Frequency Intensity Time/duration Type/mode

Frequency and Duration Trade Off

Same level of VO2 max. progression can be seen with different time and frequencies

Special Groups

Heart Disease Post- heart transplant Pulmonary diseases NIDDM- type 2 diabetes Obesity

Heart Disease as a Special Group

Coronary artery disease-> atherosclerosis (plaque build up) in 1+ arteries (over years)-> not enough oxygen to heart cells-> heart attack Treatment: diet, drugs, exercise

Post- Heart Transplant as a Special Group

New heart has no nerve connections

• Vagus Nerve: higher resting heart rate (around 100-110 bpm)

• Cardiac Accelerator Nerve: heart rate can't increase as much or as fast-> only with norepinephrine and epinephrine deliver in blood- slower Max. HR may only be around 20-40 above resting HR, slow exercise response Treatment: immunosuppressive drugs

Pulmonary Diseases as a Special Group

Most common: COPD: combination of emphysema and chronic bronchitis Also: asthma, pulmonary fibrosis (scar tissue in lungs) Sleep Apnea: less O2, more CO2-> heart beats faster to try to get little oxygen delivered to blood and CO2 to lungs to get rid of it-> higher blood pressure (the silent killer) Treatment: stop smoking, drugs, diet, exercise

NIDDM (Type 2 Diabetes) as a Special Group

Factors: family history, inactivity, obesity Symptoms (both types): polyuria, polydipsia, polyphagia, glucosuria Diagnosis: glucose challenge: see if body can handle super sugary drink- blood samples to see how well the glucose is cleared from the blood Treatment: exercise and weight loss can improve insulin sensitivity Diabetes Prevention Plan

Obesity as a Special Group

Correlated With: hypertension, insulin resistance, low HDL, osteoarthritis Increasing in children and adolescents ACSM Guidelines: no less than 1200 kcals/day; exercise up to 1000 kcals/day; rate of weight loss: up to 1 kg/week

Polyuria

excessive urination

Polydipsia

excessive thirst

Polyphagia

excessive hunger

Glucosuria

sugar in urine