Interpretation of Cardiopulmonary Exercise Testing - Nine Panel Plots

Interpretation of CPET
(Nine Panel Plots)
Presenter : Dr. Saran A. K.
Preceptor : Prof. (Dr.) Tribhuwan Kumar
DM Seminar | 22 March 2025

DEPT. OF PHYSIOLOGY, AIIMS PATNA 2
Prof. Karl Wasserman
(12 March 1927 — 22 June 2020)

Overview
• Introduction
• “9 Panel Plots” currently in use
• New Wasserman UCLA 9-Panel Plot
• Panel wise interpretation of the plots
• Summary

• Exercise is a period of enhanced energy expenditure met by
complex adjustments of metabolic, cardiovascular,
respiratory and thermoregulatory mechanisms.
• A structured physical activity, performed with the intention of
achieving physiological end point.

5
Altalag, A., Road, J., Wilcox, P., Dhillon, S`.S., Guenette, J.A. (2019). Exercise Testing. In: Altalag, A., Road, J., Wilcox,
P., Aboulhosn, K. (eds) Pulmonary Function Tests in Clinical Practice. In Clinical Practice. Springer, Cham.
The Wassermann’s Gears

Cardiorespiratory changes in during exercise
CARDIOVASCULAR CHANGES RESPIRATORY CHANGES
Exercise hyperaemia (up to 20 times)
• Arteriolar dialation
• Opening of closed capilalries
• Local metabolites, Neural and Humoral control
Increase in ventilation
• Reflexes from proprioceptors and psychic stimuli
• Increase in body temperature
• Peripheral chemoreceptor stimulation
• Acidosis produced by lactic acid accumulation
Redistribution of blood flow in the body
Reduction in blood flow to inactive muscles,
splanchnic, cutaneous and renal supply
Increased O2 uptake in the lungs
• Increased perfusion
• Increased alveolar-capillary gradient
• Increased pulmonary diffusion capacity
Increase in cardiac output
↑HR (Central command, metaboreflex, temp etc)
↑SV (↑ Venous Return)
↑Myocardial contractility
Changes at the tissue level
• Increased blood flow to muscle
• Increase in Tissue capillary fluid O2 Gradient
• Shift in ODC towards right
Changes in blood pressure ( Baroreceptor resetting)
Changes in blood volume (Haemoconcentration)
6

• Cardiopulmonary exercise testing (abbreviated CPET or
CPX) permits simultaneous evaluation of the ability of the
cardiovascular and respiratory systems to perform their
major function, that is, gas exchange between the cells and
the environment.
• Indicated in patients with different causes of exercise
limitation and unexplained dyspnoea.

8
Indications for Cardiopulmonary exercise Testing NEJM Evidence

• CPET is the gold standard method used to objectively
assess functional capacity.
• This is a non-invasive maximal exercise test, which uses
gas exchange analysis to provide information about the
respiratory, cardiovascular, metabolic and muscular
responses to physical activity.
• It allows clinicians to define the pathophysiological
limitation to exercise.

Wasserman & Whipp’s Principles of Exercise Testing and Interpretation 6th Edition

• The wealth of data generated during CPET is a major asset
of the method, as it allows a comprehensive view of the
metabolic changes at rest and during exercise.
• At the same time, this wealth of data presents a significant
challenge in terms of selection, display, management, and
interpretation.

• The variables that a cardiopulmonary exercise test aims to
measure can be presented in a number of different ways.
• The standard method of presenting these data is as a three-
by-three array of specifically arranged graphical panels - 9-
panel plot.
• Different 9-panel plots are available; which arrange individual
plots in different orientations.

A new method for detecting anaerobic threshold by gas exchange W. L. Beaver, K. Wasserman, and B. J. Whipp
Journal of Applied Physiology 1986 60:6, 2020-2027

9 Panel Plots currently in use
• The Original Wasserman 9 Panel Plot (1980s)
• The New Wasserman 9 Panel Plot (2011)
• The Whipp 9 Panel Plot (2008)
• The ERS version of the Whipp Plot
ERS = European Respiratory Society

A new method for detecting anaerobic threshold by gas exchange W. L. Beaver, K.
Wasserman and B. J. Whipp J Appl Physiol (1985) 1986 Vol. 60 Issue 6 Pages 2020-7
CPET Made Simple – A Practical Guide to Cardiopulmonary Exercise Testing Tom
Lawson and Helen Anderson

New Wasserman UCLA 9-Panel Plot
Panel 1 – VO₂ and VCO₂ versus work rate (or time)
Panel 2 – HR and VO₂/HR (oxygen pulse) versus work rate (or time)
Panel 3 – VCO₂ and HR versus VO₂
Panel 4 – VE/VCO₂ and VE/VO₂ versus time
VO₂ – Oxygen Consumption, VCO₂ – Carbon Dioxide Production, HR – Heart Rate, VE – Minute
Ventilation, VE/VCO₂ – Minute Ventilation per Carbon Dioxide Production, VE/VO₂ – Minute Ventilation
per Oxygen Consumption, PETO₂ – End-Tidal Oxygen, PETCO₂ – End-Tidal Carbon Dioxide, RER –
Respiratory Exchange Ratio, Vt – Tidal Volume.

Panel 5 – VE versus time
Panel 6 – VE versus VCO₂
Panel 7 – PETO₂ and PETCO₂ versus time
Panel 8 – RER versus time
Panel 9 – VT versus VE
VO₂ – Oxygen Consumption, VCO₂ – Carbon Dioxide Production, HR – Heart Rate, VE – Minute Ventilation,
VE/VCO₂ – Minute Ventilation per Carbon Dioxide Production, VE/VO₂ – Minute Ventilation per Oxygen
Consumption, PETO₂ – End-Tidal Oxygen, PETCO₂ – End-Tidal Carbon Dioxide, RER – Respiratory Exchange
Ratio, Vt – Tidal Volume.

Wasserman, J.E., Hansen, D.V., Sue, D.J., & Whipp,
B.J. (2020). Wasserman & Whipp's Principles of
Exercise Testing and Interpretation (6th ed.). LWW

Lawson T, Anderson H. CPET made simple: A practical guide to cardiopulmonary
exercise testing. Cambridge University Press; 2024.

The two goals of visually interpreting the exercise data in
the nine panel plots are
• Detecting any exercise limitation and
• Identifying the organ system(s) responsible for that
limitation.

Concept of Anerobic Threshold (AT)
• It is the point during incremental exercise at which lactate begins to
accumulate in the blood faster than it can be removed.
• Lactic acidosis of exercise does not take place until a minimum PO2 is
reached in the muscle venous effluent
• Supports the concept that lactate accumulation starts when the muscle O2
supply becomes critical
• It marks the transition from aerobic metabolism to a greater
reliance on anaerobic glycolysis.

Definition of Anerobic Threshold
The exercise VO2 above which anerobically produced high
energy phosphate supplements the aerobically produced high
energy phosphate with
• consecutive lowering in the cytosolic redox state,
• increase in L/P ratio and
• lactate production.
L/P ratio - Lactate/Pyruvate ratio

• Supplements aerobic metabolism- becomes insufficient at higher
levels of exercise
• Normal Value ~45–60% of predicted peak VO2 , highly variable
• AT is called anaerobic because this process is O2- independent.
• Production and accumulation of lactic acid, contributes to muscle
fatigue leading to termination of exercise. Lactate Threshold
• Buffers the rising levels of lactic acid in the blood with bicarbonate
to stabilize the pH.
AT- Anaerobic Threshold

• The extra CO2 is produced, unrelated to O2 consumed VO2
resulting in the rise of RER during exercise which often
exceeds 1 (i.e. more CO2 is produced than the O2 consumed).
• The respiratory system responds by eliminating the extra CO2,
resulting in a rise in VE out of proportion to VO2.

Altered physiological responses to exercise above AT
• Accelerated muscle glycogen utilization and anerobic regeneration
of ATP
• Reduced exercise endurance
• Metabolic Acidosis
• Delay in VO2 steady state
• Increased VO2 over the predicted aerobic metabolism
• Increased ventilatory drive

• Decreased PaCO2 and PETCO2 with time
• Bohr effect rather than PO2 leading to enhanced O2 extraction
• Increased plasma electrolyte concentration
• Hemoconcentration
• Increased concentration of intermediaries
• Increased catecholamines
• Increased double product

• Test Type and Equipment : CPET using
Bicycle Ergometer
• Age/Sex : 32 years/Male
• Height/Weight : 177cm/87 kgs
• Protocol : Auto predicted for age, sex and
daily activity(Max WR of 148 W, 15 watts
increment every minute for 10 minutes)
• Test was done for 8 minutes 15 seconds till
voluntary exhaustion?
Test Protocol and Setup

Nine Panel Plot Display in Medisoft Expair

Interpretation of Nine Panel Plots
• Each of the plots focuses on a different aspect of physiology
occurring during exercise.
• The resulting patterns differ among normal subjects and various
disease states and allow pathophysiology to be identified.
• The x-axis can again either use work rate or time as the
variable, with the resultant curves being the same.

• Horizontal lines show predicted maximums (e.g. heart rate) or
lung volumes (e.g. IC and VC). These may be extended to
show ranges (e.g. 80–100% of predicted).
• Vertical lines can show several different variables, such as the
start of loaded work/recovery, AT, or lung volumes (e.g. MVV).
• Data are often best averaged over 10 or 15 second periods for
presentation purposes.

Panel 8: RER versus Time (or WR) Plot

• The respiratory exchange ratio (RER) is the ratio of carbon dioxide
output (VCO2) to oxygen uptake (VO2) measured in expired gas.
• Under steady state conditions, it is the same as the respiratory
quotient (RQ), which is the ratio of CO2 production to O2 uptake,
measured at the cellular or tissue level.

• RER or RQ can be used to indicate what fuel source (carbohydrate or
fat) is being utilized for metabolic processes
• <0.8 implies fat is the main fuel source
• 0.8–1.0 implies a mixture of carbohydrate and fat
• >1.0 implies carbohydrate is the main fuel source
• RER at rest is <1.0, with a normal range of 0.7–1.0
• Start of exercise - slight dip in RER followed by an increase to 1.0
as muscular activity and cellular respiration increases

• At the anaerobic threshold (AT), the RER must be ≤1.0.
• Rise in RER becomes increasingly steep as HCO3– buffers lactic
acid.
• Beyond AT , RER must be >1.0 since CO2 production increases to
buffer the acidaemia caused by an increase in lactic acid
• In general, patient effort is said to be good if the peak exercise
RER is >1.15.
• Recovery phase - RER increases further, before eventually
decreasing.

Slight dip at
start
AT -RER
closer to 1
Max RER
>1.15
Recovery RER
increases the
drops

Plot 1 : VO2/VCO2 versus WR/ Time

• VCO2 plot - better overall appreciation of exercise capacity,
Reflects metabolic activity and buffering of acids
• The increase in VO2 relative to work rate (ΔVO2/ΔWR) is
dependent on
• The ability of the cardiovascular system to deliver
oxygenated arterial blood
• The ability of the musculature to extract oxygen from
arterial blood.

• VO2 (O2 uptake) is the amount of O2 in liters that the body
consumes per minute (L/min).
• VO2 (in L/min) represents the internal metabolic work and is
directly proportional to the external WR (in watts) applied
through the cycle ergometer or treadmill.
• VO2 is considered equivalent to WR under most circumstances

• Maximum VO2 ( VO2 max) (L/min): is the maximum achievable
VO2
• VO2 max can be detected when the VO2 plateaus in relation to
the external workload (WR), indicating that no further increase
in VO2 can be achieved despite increasing WR.
• VO2 max represents the maximum exercise capacity for a
given subject and is the gold standard indicator of the
subject’s cardiorespiratory fitness.

• Measured peak VO2 (L/min): The highest VO2 that a subject
actually achieves during CPET. Evidence for plateauing of VO2
despite an increasing WR is not required for the determination of
VO2 peak.
• Predicted peak VO2 (L/min): The highest VO2 that a subject is
expected to achieve. Is determined by the patient’s age, sex and
body size.
• In normal subjects, the measured peak VO2 usually equals or
exceeds predicted peak VO2

• Cardiac Disease (e.g., Cardiomyopathy).
• Chronotropic Disorders (e.g., Pacemaker, β-blockers)
• Anaemia or Carboxyhemoglobinemia
• Muscle Disease (e.g., Mitochondrial Disease)

• VO2 should increase linearly during exercise with a similar gradient
to work rate (i.e. in parallel)
• Below AT, VO₂ is more dependent on oxygen extraction and
muscle efficiency, whereas above AT, VO₂ becomes largely
CO-dependent due to the increasing demand for oxygen delivery.
AT- Anerobic Threshold

ΔVO2/ΔWR
• Referred to as work efficiency or response gain
• Marker of O2 transport and utilization, and can give a global
assessment of exercise capacity/tolerance and the presence of
exercise limitation.
• Normal range is approximately 9–12 ml/min/watt.
• Is independent of sex, age, and height.
• Can also be assessed during submaximal exercise.

AT
Beyond RCP: VCO2
increases more
Isocapnic Buffering
Peak VO2
• Plateau in VO₂ with increasing workload
✓ Respiratory Exchange Ratio (RER) ≥ 1.10
o Achievement of age-predicted max heart
rate (HRmax)
o Volitional exhaustion with high Rating of
Perceived Exertion (RPE ≥ 17)
• Blood lactate levels >8 mmol/L

Plot 3 : VCO2 versus VO2 Plot

• The AT is the point at which the gradient of the VCO2-VO2
curve changes and becomes steeper, as VCO2 increases to a
greater degree than VO2.
• Anerobic Threshold can be calculated from Plot 3 using two
methods
• V Slope Method
• Line of One Method

AT is taken as the inflection point where
VCO2 increases more than VO2 (this
increase in CO2 production is eliminated by
an increase in ventilation)
V Slope Method Line of One Method
AT is determined by visually identifying the
breakpoint in the VCO2 vs VO2 relationship using
a line with a gradient of 1. This line is moved
from right to left along the x-axis, and AT is the
first point where VCO2 exceeds VO2

• AT of >40% predicted max VO2 is considered normal.
• If patients do not reach their max VO2, figures may seem
abnormally elevated (e.g. if AT is closer to VO2 peak).
• Trained athlete 61–80%
• Normal 51–60%
• Deconditioned/mild disease 41–50%
• Abnormal <40%

AT AT % - 66 %?

Panel 4 : VEVO2 and VEVCO2 v/s Time

• Ventilatory equivalents are unitless values that describe the
ventilation (ml/min) required to either take up 1 ml of oxygen
(ml/ min) or eliminate 1 ml of carbon dioxide (ml/min).
• Act as an index of lung function, for example, inefficiency can
be shown when there is high ventilation with poor O2 uptake or
CO2 elimination.

• Exercise increases cardiac output, improving apical perfusion and
V/Q matching.
• VE/VO₂ and VE/VCO₂ decrease, indicating more efficient
ventilation.
• Lowest value for VE/VCO₂ > 32 suggests high physiological dead
space and poor gas exchange.
• Lowest value for VE/VCO₂ > 34 is linked to increased clinical risk
and potential pulmonary disease

Anerobic Threshold
• At AT, VE/VO₂ reaches its lowest point before rising as ventilation
increases to clear CO₂ from lactic acidosis.
• The rise in VE/VO₂ reflects metabolic changes, not reduced lung
efficiency, as VO₂ plateaus.
Respiratory Compensatory Point
• VE/VCO₂ starts rising at RCP, beyond AT, as CO₂ clearance
increases.
• The nadir of VE/VCO₂ is less distinct than VE/VO₂, forming a
gradual curve.

• The period between AT and RCP represents lactic acid buffering by
HCO₃⁻.
• RCP is not always observed in CPET but indicates sufficient lactate-
driven acidaemia.
• Presence of RCP suggests good exercise effort and no ventilation
limitation.
• In lung disease, ventilation is limited, preventing an RCP from
occurring.
AT- Anerobic Threshold, RCP – Respiratory Compensatory Point

AT
Lower value of VeqCO2 is 27.7
Respiratory Compensation
Point (RCP)
Isocapnic Buffering

Plot 7 : PETO2 and PETCO2 v/s Time

• Examines the end-tidal partial pressures of O2 and CO2
• PETO₂ and PETCO₂ - the pressure gradients driving gas
diffusion, give hints about ventilation and perfusion matching.
• Like mirror images of each other (with O2 plotted above CO2),
• The magnitude of changes depends on the RER.

• At the start of exercise end-tidal O2 levels will gradually fall as a
greater amount of O2 is extracted from inspired air, leaving less in
expired air.
• Beyond the AT, ventilation increases without an increase in VO2,
hence the end-tidal O2 increases to resemble inspired air again.
• At the start of exercise, end-tidal CO2 levels will gradually rise
due to increased production.
• At the RCP, ventilation increases due to acidaemia and end-tidal
CO2 begins to fall.

Initial drop in PETO2 Beyond AT - Increase
Initial rise in PETCO2
Beyond RCP - Fall
AT- Anerobic Threshold, RCP – Respiratory Compensatory Point

AT
• The AT is seen at the nadir of PETO2 (plateau or falling), that is
PETO2 must not be rising.
• For PETCO2, the AT is seen when PETCO2 plateaus and is not
falling.
RCP
• Respiratory compensation point is the point at which PETCO2
begins to fall.
• The section of the curve between these two points represents
isocapnic buffering.

AT - nadir of PETO2 (plateau or
falling) OR PETCO2 plateaus and
is not falling
Respiratory compensation
point is the point at which
PETCO2 begins to fall.
Isocapnic Buffering

• Low PETCO2 implies either hyperventilation or high V/Q ratio
(i.e. high dead space).
• Checking against RER can help determine whether
hyperventilation is acute or chronic (this can be corroborated by
arterial blood gas analysis or knowledge of plasma HCO3
–).

Panel 2 : HR and VO₂/HR vs Work Rate (or time)

• Maximum HR (bpm) = 220 – age
• Decreases with advancing age.
• Heart rate will steadily (and linearly) increase with exercise to
>85% predicted HRmax.
• Heart rate reserve (HRR) is the ability to increase HR further at
peak exercise (HRR= predicted HRmax - observed HRmax)
• Used to estimate the ‘stress’ on the cardiovascular system
during exercise.
• Normal = zero or <15–20%.

Potential reasons for not reaching HRmax
• Normal interpatient variability
• Poor effort
• Use of negative chronotropic drugs (e.g. beta-blockers)
• Disease processes (e.g. heart, lung, peripheral vascular,
musculoskeletal, etc.)

Low Heart Rate Reserve
• Impaired ventricular function (with or without pulmonary
vascular resistance), where increasing cardiac output relies on
increasing heart rate (rather than stroke volume).
This often results in a rapid rise in HR coupled with a low VO2
max.

High Heart Rate Reserve (HRmax is less than 85% predicted)
• Poor effort
• Chronotropic insufficiency, for example sick sinus
syndrome or beta-blockade
• Angina that limits exercise
• Lung disease resulting in a prematurely ending test
• Peripheral vascular disease with claudication resulting in a
prematurely ending test.

O2 Pulse : (VO2) / HR
• Stroke Volume cannot be easily measured like HR and requires a
more invasive method (e.g. cardiac catheterization).
• A search for a non-invasive method - concept of the “O2 Pulse”.
• Is defined as the O2 uptake or consumption for each cardiac
cycle, i.e. VO2 divided by the HR.
• The Fick equation can then be rearranged to calculate O2 pulse:

• The O2 pulse reflects the SV and O2 extraction and normally
increases with incremental exercise due to increases in both of
these variable
• During maximal or near-maximal exercise, CaO2–CvO2 is assumed to
be relatively constant, O2 pulse becomes equivalent to SV.
• Non-invasive surrogate marker for SV in exercise test interpretation
• Qualitative assessment of Stroke Volume.

• O₂ pulse increases linearly with VO₂ and HR, reflecting rising
stroke volume (SV).
• As exercise continues, O₂ pulse increase slows due to HR-driven
CO rise.
• Predicted O₂ pulse = Predicted VO₂ max / Predicted HR max
• Normal: >80% or >10 ml/beat
• A high O₂ pulse plateau can be normal in trained athletes nearing
max effort, by increasing SV, maintaining lower HR, and improving
oxygen extraction
76

Variations or Abnormal Responses
Low O₂ pulse
• Cardiac disease or low cardiorespiratory fitness.
• Anemia, low lung oxygenation, R-L shunt, or mitochondrial
dysfunction.
• A sudden drop or early O₂ pulse plateau may signal cardiac ischemia
or fixed SV (e.g., aortic stenosis).
High O₂ pulse
• Fitness training
• Beta-blockade use.

Heart Rate Recovery (HRR)
• HRR measures the decline in HR after exercise
cessation, typically at 1 minute.
• HRR = (Max HR - HR at 1 min recovery) / 100
• Normal if HR falls >10% within one minute of recovery
• HRR reflects autonomic nervous system function and
cardiovascular health.

Panel 5 – VE versus time, SBP

• Minute ventilation (VE) is the sum of the volumes of each breath
over the course of a minute.
• Depends on respiratory rate and tidal volume.
• VEmax is measured during CPET; however, it can also be predicted.
• Predicted maximum minute ventilation (VEmax) can theoretically be
estimated using FEV1 (measured in litres).
• Predicted VE max(L/min)= (FEV1 × 20) + 20.

Predicted VE max(L/min)= (FEV1 × 20) + 20.
= (3.21 X 20) + 20
= 64.2 + 20 = 84.2

Maximum Voluntary Ventilation (MVV)
• A measure of maximal breathing capacity.
• Assessed by measuring the maximum airflow, at rest, over a 12–15-
second period.
• This involves a form of hyperventilation, which is not recommended
before cardiopulmonary exercise testing.
• Approximated by MVV = FEV1 × 40.

Breathing Reserve /Ventilatory reserve
• The relationship between the minute ventilation seen during exercise and
the predicted maximal breathing capacity (estimated by MVV)
• Expressed as a percentage or in absolute terms.
• BR= 100(MVV-Vemax)/MVV
• i.e. breathing reserve is the % of MVV not used at peak exercise.
• Normal ≥30% or 15 L/min

• Normal response : Minute ventilation (VE) increases with exercise
and workload
• VE does not normally limit exercise.
• Exercise tends to be limited by cardiac output (in healthy subjects and
those with cardiac disease).
• Hence, VEmax does not reach 70% predicted and there is a high
ventilatory reserve.

In lung diseases
• If peak VO2 is low and
• the subject stops due to ventilatory limitation (VEmax >70%),
• it is likely that their HR will be <85% predicted maximum.
• May appear as if the test has ended prematurely, before maximum
capacity has been reached.
• Lung disease patients will likely have little to no BR at peak exercise.

Panel 6 – VE versus VCO2

• Minute ventilation (VE) increases with exercise along with carbon
dioxide production (VCO2).
• Hence the plot should be linear.
• Beyond the AT, lactate accumulation results in an acidaemia.
• This is initially compensated for by HCO3 (isocapnic buffering) which
increases VE
• However, at the respiratory compensation point (RCP), VE starts to
increase at a higher rate

Parameter Normal Abnormal Interpretation
VE/VCO₂ slope <30 >32
High VE, low VCO₂ • Hyperventilation,
poor lung perfusion
• High dead space,
ventilatory
inefficiency

Respiratory compensation point

Plot 9 : Vt vs VE

• The relationship between tidal volume (Vt) and minute
ventilation (VE).
• The curves may include dashed lines that intersect axes to
represent additional parameters.
• Y-axis – vital (VC) and inspiratory capacities (IC)
• X-axis – maximum voluntary ventilation (MVV).
• The normal shape of the curve is a ‘dogleg’ or building up to a
plateau.

• At low-intensity exercise, VE increases mainly due to increasing
tidal volume.
• As intensity increases, further increases in VE are achieved by
increasing respiratory rate, whilst VT tends to plateau

• Patients with lung disease rely on increasing respiratory rate and
have flatter curves, reaching a plateau earlier.
• A shallow, flatter curve implies obstructive disease.
• A steep curve approaching inspiratory capacity implies restrictive
disease.

References
99
1. Wasserman & Whipp’s Principles of Exercise Testing and Interpretation 6th
Edition
2. Lawson T, Anderson H. CPET made simple: A practical guide to cardiopulmonary
exercise testing. Cambridge University Press; 2024.
3. Alotaibi, A., Road, J., Wilcox, P., & Aboulhosn, K. (Eds.). (2022). Pulmonary
Function Tests in Clinical Practice (2nd ed.). Springer.
4. Kinnear, W., & Hull, J. H. (2021). A practical guide to the interpretation of
cardiopulmonary exercise tests (2nd ed.). Oxford University Press.
5. Altalag, A., Road, J., Wilcox, P., Dhillon, S`.S., Guenette, J.A. (2019). Exercise
Testing. In: Altalag, A., Road, J., Wilcox, P., Aboulhosn, K. (eds) Pulmonary
Function Tests in Clinical Practice. In Clinical Practice. Springer, Cham
6. A new method for detecting anaerobic threshold by gas exchange W. L. Beaver,
K. Wasserman, and B. J. Whipp Journal of Applied Physiology 1986 60:6, 2020-
2027

THANK YOU !
saran.adhoc@gmail.com

Interpretation of Cardiopulmonary Exercise Testing - Nine Panel Plots

More Related Content

Similar to Interpretation of Cardiopulmonary Exercise Testing - Nine Panel Plots (20)

More from Saran A K (20)

Recently uploaded (20)

Interpretation of Cardiopulmonary Exercise Testing - Nine Panel Plots