1. ACE Personal Trainer Manual
5th Edition
Chapter 8: Physiological Assessments
Lesson 8.2

2. After completing this session, you will be able to:
LEARNING OBJECTIVES
After completing this session, you will be able to:
Discuss the various assessments of cardiorespiratory fitness, and the appropriateness of each
Demonstrate and evaluate the results of various cardiorespiratory fitness assessments:
Cycle ergometer test
Ventilatory threshold testing
Field tests
Step test

3. CARDIORESPIRATORY FITNESS (CRF) TESTING
CRF – how well the body performs dynamic activity using large muscle groups at a moderate-to-high intensity for extended periods of time:
Valuable in assessing overall health
Depends on the efficiency and interrelationship of the cardiovascular, respiratory, and musculoskeletal systems
Exercise testing for CRF is useful to:
Determine functional capacity, using predetermined formulas based on age, gender, and body weight
Determine a level of cardiorespiratory function [maximal oxygen uptake (VO2max) or metabolic equivalent (MET) level] to serve as a starting point
Determine underlying cardiorespiratory abnormalities that signify progressive stages of cardiovascular disease
Periodically reassess progress following a structured fitness program

4. Submaximal CRF tests are more appropriate in a fitness setting:
VO2MAX AND CRF
VO2max:
An estimation of the body’s ability to use oxygen for energy
Closely related to the functional capacity of the heart
An excellent measure of cardiorespiratory efficiency
Involves the collection and analysis of exhaled air during maximal exercise in a laboratory
Submaximal CRF tests are more appropriate in a fitness setting:
Provide accurate values that can be extrapolated to determine expected maximal efforts
Maximal effort is not appropriate for all populations
Repeated research demonstrates that as workload increases, so do heart rate and oxygen uptake. In fact, heart rate and oxygen uptake exhibit a fairly linear relationship to workload.
This relationship allows the personal trainer to estimate VO2max from the heart-rate response to exercise with fairly good accuracy. The lack of accuracy related to estimated maximum oxygen uptake is influenced by two key variables:
Many estimation calculations are based on the of 220 – Age equation for estimating MHR. This formula is subject to a standard deviation of approximately ±12 beats per minute (bpm). This means that in a group of year-old individuals (for whom this standard MHR calculation would yield an MHR of 180 bpm), the actual MHR for 68% of them would range between 168 and 192 bpm, while the remaining 32% would fall further outside that range.
Maximal oxygen uptake is determined by estimating MHR at submaximal workloads. The charts and equations that are used to determine maximal oxygen uptake are based on the assumption that everyone expends exactly the same amount of energy and uses the same amount of oxygen at any given work rate (remember, VO2max is calculated from equations devised after repeated tests that actually measured oxygen consumption). For this reason, a submaximal test is likely to underestimate or overestimate the true maximum for a given individual. The true value of submaximal cardiorespiratory testing comes when the client can repeat the same test a few months later and then compare his or her individual test results.

5. CARDIORESPIRATORY ASSESSMENTS
Labs typically provide a controlled environment:
Generally a more private setting
Constant temperature
Equipment is centrally located for easy test administration
Graded exercise test (GXT):
Directly measures maximum heart rate (MHR) with an electrocardiogram (EKG) monitoring device
Typically uses a treadmill, cycle ergometer, or arm ergometer
In a clinical setting, GXT is performed to maximal exertion and terminated when:
The client can no longer tolerate the activity
Signs or symptoms arise that warrant termination
The client achieves a predetermined age-predicted MHR
Two methods exist for determining MHR. The most accurate way is to directly measure the MHR with an EKG monitoring device during a graded exercise test (GXT). The other way is to estimate MHR by using a simple prediction equation or formula.
Some of the GXTs are administered in stages that incorporate gradual increases in exercise intensity, while others measure the heart-rate response to a single-stage bout of exercise. On a treadmill, the intensity is raised by increasing the speed and/or elevation; on the cycle or arm ergometer, the intensity is generally raised by increasing resistance, while the cadence, measured in revolutions per minute, is generally held constant.
There are certain risks associated with maximal GXTs, the most severe being cardiac arrest. For this reason, maximal exercise tests are not typically administered in fitness centers or other nonclinical settings.

6. MAXIMAL OXYGEN UPTAKE (ML/KG/MIN): MEN
Submaximal exercise testing is safer and, in many cases, provides a reliable indicator of maximal effort. The information obtained from a submaximal exercise test can be used to determine VO2max. The workload can also be measured in METs. Workload is a reflection of oxygen consumption and, hence, energy use (i.e., 1 MET is the equivalent of oxygen consumption at rest, or approximately 3.5 mL/kg/min).
In addition to measuring cardiorespiratory fitness, a GXT is a valuable tool in identifying those who are at risk of a coronary event. The major indicators include:
A decrease—or a significant increase—in blood pressure with exercise: SBP that is lower during exercise compared to SBP taken immediately prior to the test in the same posture as the test is being performed (i.e., baseline measurement); SBP that rises above 250 mmHg during exercise; or SBP that increases during immediate post-exercise recovery
An inadequate HR response to exercise: An increase in HR of <80% of age-predicted value or <62% for clients on beta blocker medication during exercise
Exercise duration: Stated simply, the longer the individual can tolerate the treadmill test, the less likely he or she is to die of CAD—or of any cause.
Heart-rate recovery: An individual standing in an upright position should show a reduction of 12 bpm at one minute post-exercise, and an individual in a sitting position should show a reduction of 22 bpm two minutes post-exercise.
In addition to monitoring heart rate and blood pressure during the initial interview, it is essential to monitor the client before, during, and after any GXT. The following variables should be constantly assessed and recorded during an exercise test:
Heart rate: Monitor continuously and record during the last 15 seconds of each minute
Blood pressure: Measure and record during the last 45 seconds of each stage
Ratings of perceived exertion (RPE): Record during the last five seconds of each minute
Signs and symptoms (S/S): Monitor continuously and record both personal observations and subjective comments from the client

7. MAXIMAL OXYGEN UPTAKE (ML/KG/MIN): WOMEN

8. CYCLE ERGOMETER TESTING
Used to estimate VO2max without maximal exertion:
Advantages:
Performed in a controlled environment
Stationary cycles are easy to maintain and portable
Easier to measure exercise heart rate (HR) and blood pressure (BP) because the arms are relatively stationary
Suitable for those with balance problems or unfamiliarity with a treadmill
Disadvantages:
Clients may not be used to cycling; the test may underestimate the client’s actual CRF due to premature leg fatigue
Exercise BP may be higher (than if using a treadmill test)
Accuracy is based on an initial MHR prediction
As long as the heart rate has achieved a steady state at an appropriate workload, exercise HR can be used to predict VO2max.
Contraindications:
Cycle ergometer testing should be avoided when working with:
Obese individuals who are not comfortable on the standard seats or are physically unable to pedal at the appropriate cadence
Individuals with orthopedic problems that limit knee range of motion (ROM) to less than 110 degrees
Individuals with neuromuscular problems who cannot maintain a cadence of 50 rotations per minute (rpm)

9. YMCA BIKE TEST
Measures HR response to incremental, three-minute workloads that progressively elicit higher HR responses:
Immediate post-exercise HR (HRss) responses are plotted on a graph against workloads performed
As exercise HR correlates to a VO2 score, the HR response line is extended to determine:
Maximal effort (i.e., MHR)
An estimate of VO2max
This test is commonly used in university settings and clinical research, and it is therefore important for personal trainers to understand the protocol and applications.

10. YMCA BIKE TEST PROTOCOL

11. HEART-RATE RESPONSE TO CYCLING
Heart-rate responses to three submaximal work rates for a 50-year-old, sedentary male weighing 79 kg (174 lb).
VO2max was estimated by extrapolating the heart rate (HR) response to the age-predicted maximum HR of 173 beats per minute [based on 208 – (0.7 x Age)]. The work rate that would have been achieved at that HR was determined by dropping a line from that HR value to the x axis. VO2max is estimated to be 2.1 L/min. The other two lines estimate what the VO2max would have been if the subject’s true maximum HR was ±1 standard deviation (s.d.) from the 173 beats/minute value.
VO2max conversion
Oxygen uptake is dependent on the size of the individual being tested.
To compare VO2max among individuals of different weights, oxygen uptake (in milliliters) must be divided by body weight (in kilograms).
To calculate this conversion, perform the following steps:
Convert L/minute to mL/minute by multiplying by 1,000
Convert body weight in pounds to kg by dividing by 2.2
Divide mL/kg
Oxygen uptake is always measured per minute, so the units become mL/kg/min.

12. VENTILATORY THRESHOLD TESTING
As exercise intensity increases, ventilation increases somewhat linearly.
At certain intensities, metabolic changes occur in the body.
First ventilatory threshold (VT1):
Represents the intensity where blood lactate accumulates faster than it can be cleared
This causes faster breathing to blow off the extra CO2 produced by the buffering of acid metabolites.
Second ventilatory threshold (VT2):
Occurs where lactate rapidly increases with intensity
Represents hyperventilation relative to the extra CO2 being produced
Blowing off CO2 is no longer adequate to buffer the increase in acidity occurring with progressively intense exercise.
Prior to VT1, fats are a major fuel and only small amounts of lactate are being produced. The cardiorespiratory challenge to the body lies with inspiration and not with the expiration of additional amounts of CO2 (associated with buffering lactate in the blood). The need for oxygen is met primarily through an increase in tidal volume and not respiratory rate.
An important note for testing purposes is that the exercise intensity associated with the ability to talk comfortably is highly related to VT1. As long as the exerciser can speak comfortably, he or she is almost always below VT1. The first point where it becomes more difficult to speak approximates the intensity of VT1, and the point at which speaking is definitely not comfortable approximates the intensity of VT2.
Contraindications:
This type of testing is not recommended for:
Individuals with certain breathing problems [i.e., asthma or other chronic obstructive pulmonary disease (COPD)]
Individuals prone to panic/anxiety attacks, as the labored breathing may create
discomfort or precipitate an attack
Those recovering from a recent respiratory infection

13. VENTILATORY EFFECTS DURING AEROBIC EXERCISE

14. Test objectives: VT1 represents:
SUBMAXIMAL TALK TEST FOR VT1
Test objectives:
Measure the HR response at VT1 by progressively increasing exercise intensity and achieving steady state at each stage, and
Identify the HR where the ability to talk continuously becomes compromised
VT1 represents:
The intensity where the individual can continue to talk while breathing with minimal discomfort
An associated increase in tidal volume that should not compromise breathing rate or the ability to talk
Progressing beyond this point where breathing rates increase significantly will render the test inaccurate.
Applying the results of the talk test for VT1:
The HR at VT1 can now be used as a target HR when determining exercise intensity. Those interested in sports conditioning and/or competition would benefit from training at higher intensities, but those interested in health and general fitness are well-served to stay at or slightly below this exercise intensity.

15. VT2 THRESHOLD TEST Onset of blood lactate accumulation (OBLA):
Historically refers to the lactate threshold or anaerobic threshold, and corresponds with VT2
Occurs when blood lactate accumulates at rates faster than the body can buffer and remove it
Represents an exponential increase in the concentration of blood lactate, indicating an exercise intensity that can no longer be sustained
Continually measuring blood lactate is an accurate method to determine OBLA and the corresponding VT2
Lab testing – limitations include equipment accessibility, technical expertise, cost, and collecting blood samples
Field testing – only estimates VT2; influenced by environmental variables; does not assess any direct metabolic responses beyond heart rate
OBLA point has historically been referred to as the lactate threshold or anaerobic threshold, and corresponds with VT2.
The cost of lactate analyzers and handling of biohazardous materials make it impractical for most fitness professionals.
Consequently, field tests have been created to challenge an individual’s ability to sustain high intensities of exercise for a predetermined duration to estimate VT2.
This method of testing requires an individual to sustain the highest intensity possible during a single bout of steady-state exercise.
This obviously mandates high levels of conditioning and experience in pacing.
Consequently, VT2 testing is only recommended for well-conditioned individuals with performance goals.

16. EFFECT OF TRAINING ON LACTATE THRESHOLD
Applying the results of the VT2 threshold test:
The lactate threshold and corresponding VT2 are commonly related to performance. For example, if two athletes with the same VO2max are competing, the athlete with the higher lactate threshold will likely outperform the other athlete. Lactate threshold is improved by endurance training and high-intensity training (up to 105% of VO2max). At these intense training levels, the body can respond and adapt to the increased workloads, thereby “clearing” the blood lactate at a more efficient rate. In essence, lactate-threshold training shifts the lactate curve to the right.

17. If performing field tests outside:
FIELD TESTING
Offers reliable testing for those who do not have access to traditional testing equipment found in a fitness center or health club:
Simple to administer – groups or self-administered
Involves very little expense
If performing field tests outside:
Be mindful of weather conditions
Avoid exercise testing during extreme heat, humidity, or cold
Contraindications:
Outdoor walk/run testing is not appropriate:
In extreme weather conditions
For individuals with health challenges that would preclude continuous walking (e.g., intermittent leg claudication, or osteoarthritis of the knee or hip)
For individuals with breathing difficulties exacerbated by pollution or outdoor allergens
Running tests are not recommended for those who are deconditioned.

18. ROCKPORT FITNESS WALKING TEST (1 MILE)
Estimates VO2max from a client’s immediate post-exercise heart rate response by completing a 1-mile (1.6-km) walking course as fast as possible:
Easy to administer – a running track or treadmill
Inexpensive to conduct
Suitable for many individuals – large groups or self-administered
Generally under-predicts VO2max in fit individuals; therefore may not be the most appropriate test for that group
Research has shown that clients using a treadmill and walking on a track achieved similar VO2max results. When the weather is inclement and/or a track is not available, a treadmill test can be administered.

19. 1.5-MILE RUN TEST
Measures cardiovascular and muscular endurance of the legs by completing 1.5 miles as quickly as possible:
Running track – preferred setting
Effective pacing is important for a successful outcome
Not suitable for those less-conditioned
The 1.5-mile (2.4-km) run test is used by the U.S. Navy to evaluate cardiovascular fitness levels of its personnel.

20. Little investment in supplies (step and risers)
STEP TEST
Step tests require the subject to step continuously at a specific cadence or pace for a predetermined timeframe:
Fitness level is determined by HRss
The lower the exercising or recovery HR, the higher the level of fitness
Little investment in supplies (step and risers)
Takes very little time (usually 3 minutes)
Easy to administer – large groups or self-administered
Not the most appropriate test for fit individuals:
Requires less effort; fit individuals will recover from exercise faster than those who are less fit
Contraindications
Due to the nature of step testing, this assessment may not be appropriate for:
Individuals who are extremely overweight
Individuals with balance concerns
Individuals with orthopedic problems (e.g., knee or low-back)
Individuals who are extremely deconditioned, as the intensity of the test may require near-maximal effort
Individuals who are short in stature, as they may have trouble with the step height

21. YMCA SUBMAXIMAL STEP TEST
Measures cardiorespiratory endurance
Suitable for low-risk, apparently healthy, nonathletic individuals ages 20 to 59
For those who score “below average” to “very poor,” it will be necessary to be conservative in the initial exercise program. Keeping exercise duration and intensity to a minimum will be important. For those who score “above average” to “excellent,” it would be appropriate to focus on exercise duration as well as intensity.

22. SUMMARY
Assessments are an integral part of any personal-training program.
When conducted properly, assessments for cardiorespiratory fitness can provide valuable fitness and performance information for the trainer to use in exercise program planning and implementation.
Not all tests are suitable for all populations. It is up to the trainer to decide the timing and most appropriate battery of tests for each individual client.
Periodic reassessments are also important to gauge progress and continue to foster the client–trainer relationship.