Clinical Exercise Physiology

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