Transcript testing

Exercise testing
Laboratory exercise testing:
W170
and
maximal tests
W170
Exercise test estimating theoretical physical
working capacity at hear rate of 170 beets/min.
The test is looking for a theoretical load (P) [W] which
should be produced by tested person at his (her) HR
170 beets/min.
Physiological principle:
A linear relation (positive correlation) between HR and intensity
of exercise (load) in a range from 120 to 170 (180) beets/min.
Note: There is no change in systolic volume from 120–170 (180) beets/min and therefore
cardiac output depends only on heart rate. Systolic volume rises till 120 beets/min, from
170–180 beets/min slightly decreases (short diastole).
*
W170
Next characteristics:
1) It is one of the oldest sub-maximal tests evaluating fitness level,
an effect of a training or impact of a rehabilitation intervention….
2) There was a hypothesis of strong correlation of the test with an
aerobic power (VO2max). However, current findings show, that
the test is valid only for common population (mainly for men). It
is not suitable for athletes.
3) HR 170 beets/min is approximately the value when is a healthy
young man reaching his anaerobic threshold. For the elderly or ill
(who has reduced HRmax and HR at AnT) is sometimes used
modification of the test W150 či W130.
*
W170
Equipment: - cycle ergometer
- HR monitor
Protocol:
1) 2(sometimes 3–4) stages. There can be 1 min long optional pause
between stages.
2) duration of each stage 4–6 min (reaching of steady state)
3) measurement of HR at the end of each stage (during last 15 s)
4) load [W] should increase HR:
- at the end of the 1. stage: 120–140 bpm
- at the end of the 2. stage: 140–160 bpm
*
W170
Determination of the load [W] per kg of weight:
♂
♀ and
trained
children
1. stage
1,5 W/kg 1 W/kg
2. stage
2 W/kg
≥ 2 W/kg
1,5 W/kg ≥ 2,5 W/kg
Final power depends on pedal rate as well. The pedal rate should be kept
in the range ±5 revolution/min.
Optimal pedal rate for sedentary is 60 rev/min (55–65), for trained higher
(even 85–95). The higher is load, the higher should be pedal rate.
*
W170
Protocol (♀ 60 kg):
145 bpm
[W]
125 bpm
90 W
Result of the test:
1) 60 W = 125 bpm
2) 90 W = 145 bpm
3) x W = 170 bpm
HR 2
HR 1
60 W
2. stage
1. stage
[min]
5 min
5 min
*
Calculation of W170 (extrapolation)
×
×
140
*
Calculation of W170 (extrapolation)
Result of the test:
1) 60 W = 125 bpm
2) 90 W = 145 bpm
3) 140 W = 170 bpm
×
×
Index W170:
140 W : weight (60) = 2,33 W/kg
140
*
W170
Population norms:
(Heller, 2005)
*
Comparison of a untrained (N) and a trained (T) with
use of three stages
*
W170
To create a line, two points are enough. It means to realize W170, two
exercise stages should be enough too. There are some authors who
recommend at least three stages. More stages reduce the risk of error.
×
×
×
*
W170
Note:
If the HR at the end of the first stage is lower than 120 bpm, there
may be a risk of major error. The reason is linearity from 120 to
170…..
In this case it is useful to add the third stage.
*
W170
W170 test can be use for evaluation of working
capacity at higher HR as well. However, by reason of
above mentioned problems of linear relation… there
is at HR higher than 170-180 bpm increase in error
of the evaluation.
W170 test can be use for indirect determination o aerobic power:
1) Realization of standard test and determination of load at HRmax
which can be calculated from formula 220-age
2) Determined load is used in formula (Bunc, 1989):
VO2max (ml/min) = 10.88 × [W] + 411
- This formula can be used for load from 100 to 400 W, with
considered error 10%.
*
Indirect determination of VO2max for ♀ 60 kg, 20 year
W at HRmax?
1) 220-20= 200 bpm
2) 190 W = 200 bpm
×
VO2max = 10.88 × [W] + 411
VO2max = 10.88 × 190 + 411
VO2max = 2478 ml/min
×
2478 : weight (60 kg)
VO2max = 41,3 ml/kg/min
140
190
*
Maximal exercise test
Laboratory tests when the load is gradually
increasing till maximum.
The main aim is to measure maximum oxygen
consumption (aerobic power) - VO2max(peak). It
means to evaluate efficiency of cardiovascular system
and estimate working capacity or working tolerance.
Sometimes is called spiroergometri.
A working capacity is a load reached immediately before appearance of the signals of
ischemia on EKG record, which are the reasons to stop the test. A working tolerance is
the highest load at the maximum, when the criteria for termination of the test were
reached.
*
Maximal exercise test
The sources of the load:
- cycle ergometer
- treadmill
- arm ergometer
Next equipment:
- HR monitors
- unit for pulmonary gas exchange (PGE) measurement
- analyzers for measurement of O2 a CO2 in inspired and expired air
(importance of calibration one time per day- mixture of gases: e.g. CO2 – 5
%, O2 – 15 %, rest N2)
- flow sensor measuring volume of inspired and expired air
(importance of calibration before every measurement)
Every devises are controlled from one PC = spiroergometrics unit
*
Spiroergometrics unit
Mixture of calibration gases
Calibration pump
Suction pump for EKG
Suction electrodes EKG
PC
HR receiver
Unit for PGE measurement
EKG
Unite for pulmonary gas exchange
measurement
Measurement of O2 consumption and CO2 production
- from difference in concentration in inspired and expired air
Measurement of ventilation
- calculation from breathing frequency and tidal volume
Tested person wears mask or mouthpiece with clamp
Mouthpiece – discomfort, but lower death space
Maska – comfortable (breathing via nose), but bigger death space
(accumulation of CO2) + leaking.
*
*
Air sampling for CO2 a O2 analysis
Information about
volume of inspired and
expired air
Mast fit.
Flow sensor working on principle different pressure in the front of
and behind of membrane.
Disinfection and calibration prior to each measurement.
Maximal exercise test
Increase in the load:
- continual (ramp) test
[W]
O2
[W/kg]
There is steples increase in
the load [W] till maxima.
Problem: delay in O2 consumption
VO2 does not correspond with the
load.
[min]
*
Maximal exercise test
Increase in the load:
- gradual (step) test
[W]
There is gradual increase in
load [W] with use of steps
from low values to maxima:
[W/kg]
0,5; 1; 2–5 min.
O2 consumption corresponds to
the load at the end of each step
(reaching steady state)
[min]
*
Maximal exercise test
Increase in the load:
Every minute (step) increase about o 1/3 W/kg of waight. VO2
should not increase between steps more than 3 METs.
- ♂ 75 kg = 25 W/min
- ♀ 60 kg = 20 W/min
Total duration of the test should be from 8–12 min.
If the test is shorter or longer, VO2max values are lower.
Generally – for sedentary, obese and elderly, tests should e longer with lower
increase in load)
*
Maximal exercise test
Increase in the load :
Sedentary male:
Wmax = 175 (around). If increase about 25W/min, duration
will be 7 minutes.
Trained cyclist
Wmax = 550 (or more). If increase about 25W/min, duration will be 22
minutes.
Solution:
higher increase (30 W) + change in exercise protocol:
1) 4–5 min warming-up at constant low intensity
2) test starts at the load corresponding with load at individual
anaerobic threshold
*
Maximal exercise test
Sedentary: 7 steps x 25 W = 175 W
175 W
*
Maximal exercise test
Trained would need by 22 steps x 25 W = 550 W
Problem:
1) Long duration
2) Low (boring) intensity at the beginning
ACCORDINGLY
550 W
*
Maximal exercise test
Trained would need by 22 steps x 25 W = 550 W
Problem:
1) Long duration
2) Low (boring) intensity at the beginning
ACCORDINGLY
550 W
Minute long brake, not necessary
W at AnT
Test:
3–8 min
4–5 min
*
Maximal exercise test
How to estimate AnT?
THAN
1) Based on population norms...
2) By using W70 test, which could serve as a warming-up at the same time
550 W
W at AnT
test:
3–8 min
4–5 min
*
Maximal exercise test
How to estimate AnT?
Using W170 test as a warming-up before test to maximum
550 W
W 170
Test:
3–8 min
2. step
1. step
*
Maximal exercise test
Chosen monitored parameters:
1) Heart rate (HRmax, HR at AnT) and saturation
Saturation
HR
Digital pulse oxymetere
A saturation means
percentage of
saturation of blood bye
O2 from maximum
possible amount.
It is at the rest about
98% and decreases
during exercise. It can
be lower than 90% at
maximum exercise.
*
Maximal exercise test
Chosen monitored parameters:
1) Heart rate (HRmax, HR at AnT) and saturation
2) Power – P (Wmax, W at AnT)
Work = force acting upon a distance
= [N × m] = [J]
power = work for time
= [Nm/s] = [W]
Or…
force
speed
P=F×v
[W = Nm/s]
*
Maximal exercise test
Chosen monitored parameters:
1) Heart rate (HRmax, HR at AnT) and saturation
2) Power – P (Wmax, W at AnT)
The values of Wmax/kg:
♂
♀
trained
KVS illnesses
3,5
2,8
≥6–9
od 0,5
See next table:
*
*
Maximal exercise test
Chosen monitored parameters:
1) Heart rate (HRmax, HR at AnT) and saturation
2) Power – P (Wmax, W at AnT)
3) Lactate – for estimation of so called metabolic AnT
*
Invasive estimation of AnT from level of a blood lactate
(Placheta et al, 2001)
*
Maximal exercise test
Chosen monitored parameters:
1) Heart rate (HRmax, HR at AnT) and saturation
2) Power – P (Wmax, W at AnT)
3) Lactate – for estimation of so called metabolic AnT
4) Gas exchange (O2 a CO2) and ventilation
RQ =
CO2
RQ of fats = 0,7. RQ of carbohydrates = 1
O2
However during maximal exercise test RQ overlap level of 1. The reason is
reduction of acidity with help of bicarbonates:
H++ HCO-3 → H2CO3 → H2O + CO2
Note: H2CO3 - carbonic acid
*
Maximal exercise test
However during maximal exercise test RQ overlap level of 1. The reason is
reduction of acidity with help of bicarbonates:
H++ HCO-3 → H2CO3 → H2O + CO2
CO2
[l]
O2
Deflection point from
linear trend between CO2
output and exercise
intensity.
AnP
[W]
*
Maximal exercise test
This deflection point represent anaerobic threshold,
which is called as a respiration or ventilation AnT.
Similar increase (deflection point) can be seen on the curve of ventilation - because
increase of pCO2 in blood stimulates ventilation (due to chemoreceptors).
V
[l]
So called „talking“ test
can be used for estimation.
Ventilation AnT
[W]
*
Determination of ventilation AnT
(Tvent)
(Heller, 2005)
*
V-slope method for determination of
AnT
Linear relation is
disturbed for the
benefit of CO2
output.
*
O2 consumption during maximal test
(Heller, 2005)
*
O2 consumption during maximal test
Plateau in O2 consumption:
1) It is situation when VO2max is reached and next increase in exercise
intensity does not cause father increase of it.
2) It is possible to sustain for seconds (trained longer).
3) It is evident among less then 50% tested. The most of the tested finish
early from reason of uncomfortable filings.
4) It is one criteria for reaching maximum exercise intensity.
*
Maximal exercise test is ended when the tested feels
inability to continue - reaching volitional maximum
Maximum = at lest 18.
(Borg, 1982)
*
Criteria of reaching maximum
1) Plateau in VO2.
2) RQ higher than 1.
3) Lactate is 1,5 min after cessation of exercise >8mmol/l
4) HRmax >85 % from predicted maximum
VO2max x VO2peak.
*
Maximum test on treadmill
The example of the set used in our laboratory:
4 min
1 min
than increase every 30 s
Tr. ♂
km/hour
%
8
0
8
5
10 11 12 13 14 15 15
5 5 5 5 5 5 7
Tr. ♀
km/hour
%
7
0
7
5
8
5
9 10 11 12 12 12
5 5 5 7 9 11
Than increase
in inclination
about 2 %
*
Receiver of HR.
Safety belt.
Maximum test on treadmill
Example of next protocols:
*
Some parameters during maximal test
VCO2 – volume of expired CO2, RER – respiration quotient, V – ventilation,
FIO2–FEO2 – utilization of O2 from ventilated air
*
Some parameters
during maximal test
VE
– ventilation
VCO2 – volume of expired CO2
VO2
– volume of inspired O2
PETO2 – partial pressure of O2 at
the end of expiration
PETCO2 – partial pressure of CO2
the end of expiration
LA
– level of lactate
HCO3- – bicarbonate
R
– respiration quotient
pH
– pH
W
– load
*
Results of maximal exercise test
Results of maximal exercise test
Results of maximal exercise test
Results of maximal exercise test
VO2l/min
Measurement of VO2 in the field conditions
A
B
*
Determination of VO2max from regression equation
(Jurča el al.)
1. Evaluation of physical activity
*
Determination of VO2max from regression eguetion
(Jurča el al.)
2. Filing of different parameters
*
Výpočet VO2max dle regresní rovnice (Jurča el al.)
3. Final evaluation of results
*
Literature:
Heller, J. (2005). Laboratory Manual forHuman and Exercise Physiology.
Charales Univeristy in Prague: The Karolinum Press.
Maud,  C. Foster (Eds.). Psychological assessment of human fitness.
Champaign, IL: Human Kinetics.
Placheta, Z., Siegelová, J., Štejfa, M., Jančík, J., Homolka, P., & Dobšák, P. (2001).
Zátěžové vyšetření a pohybová léčba ve vnitřním lékařství. Brno: Masarykova
Univerzita.
Silbernagl, S., & Despopoulos, A. (1988/1993). Atlas fyziologie člověka
(E. Trávničková et al., Trans.). Praha: Grada.
*