This study compared two metabolic carts, the Vmax and Innocor, during rest and exercise. The study found no significant differences between the carts at lower workloads but a deviation at higher workloads of 200 Watts or more, likely due to differences in gas analysis techniques. Both carts can measure metabolic measurements like VO2 and VCO2 but the Vmax has limitations of cost, mobility, and skill required compared to the Innocor.

1. Vmax and Innocor
Acomparisonoftwometaboliccartsduringrestandexercise
Zach Blain

2. Methods
• The volume of oxygen consumed and utilized by working muscle per
minute during rest or exercise.
• Defined by Fick:
• VO2 = Q × a-vO2 difference
• Q = SV × HR
• Q= Cardiac output; SV= Stroke volume; HR= Heart rate
• Calculated as:
• VO2 = [VE × (FEN2 / FIN2) × FIO2] – [VE × FEO2]
• VE= Ventilation, volume/min; FEN2= Fraction of expired nitrogen; FIN2= Fraction of inspired
nitrogen; FIO2= Fraction of inspired oxygen; FEO2= Fraction of expired oxygen
• To measure Q
• Pulmonary artery catheter (PAC)
• To measure a-vO2 Diff
• Arterial venous catheter
• blood sampling

3. How they work
Innocor
• Flowmeter
• Gas Analyzer
• Oxygen sensor
Vmax
• Flow/Volume
• O2 Analyzer
• CO2 Analyzer
• Flash Multi-Gas
Innocor Vmax

4. Purpose
The aim of this study is to compare the metabolic
measurements between Vmax and Innocor simultaneously
during rest and exercise.
Hypothesis
It is hypothesized that there will be no difference between Vmax
and Innocor during rest and exercise.

5. Design and Protocol
• Simultaneous measurements
• Baseline
• 50 W
• 100 W
• 150 W
• 200 W
• 250 W
• 300 W
• Staged steady state
exercise - 2 minutes

6. Demographics
Patient Demographics
Participants(male/female) 7 (4/3)
Age (years) 24 ± 3
Height (cm) 171 ± 8
Weight (kg) 73 ± 20
BMI (kg/m²) 25 ± 6

7. Absolute VO2/ VCO2 vs. Workloads
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0 50 100 150 200 250 300
VO₂(L/min)
Workload (Watts)
Vmax
Innocor
*
* Significant Difference P< 0.05
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0 50 100 150 200 250 300
VCO₂(L/min)
Workload (Watts)
Vmax
Innocor
*
Figure 2: Absolute VO2 (L/min) vs Workload (Watts) Figure 3: Absolute VCO2 (L/min) vs Workload (Watts)

8. Ventilation
0
0.5
1
1.5
2
2.5
3
3.5
4
0 50 100 150 200 250 300Vt(litersperbreath)
Workload (Watts)
Vmax
Innocor
0
10
20
30
40
50
0 50 100 150 200 250 300
RR(breathspermin)
Workload (Watts)
Vmax
Innocor
Figure 4: Respiration rate (breaths per min) vs.
Workload (Watts)
Figure 5: Tidal volume (liters per breath) vs.
Workload (Watts)

9. Discussion
• No significant change in results for low workloads
• After 200W there becomes a deviation in the results
• No significant difference in the respiration, at any
workload
• VO2 and VCO2 at high workloads (300W)
• Account for gas analysis
• FIO2 and FEO2

10. Features
Features
Safe Yes Yes
Start up cost 160,000 60,000
Mobility Minimal Maximal
Skill required Maximal Minimal
Range Rest- Maximal? Rest-Maximal?
Issues
Technician
Mouthpiece discomfort
Vmax Innocor

11. Conclusion
Both Vmax and Innocor can attain similar
results for lower workloads, but begin to drift
during higher workloads.

12. Acknowledgments
• Brad Byers
• Desi Fuhr
• Karishma Kapoor
• Linn Moore
• Melissa Bouwsema
• Michael Stickland
• Vince Tedjasaputra

13. References
• Allen et al. (2013). ACSM’s Guidelines for exercise testing and prescription.
Baltimore, MD. Wolters Kluwer, Lippincott Williams &Wilkins
• Beekley et al. (2004). Cross-Validation of the YMCA Submaximal Cycle
Ergometer Test to Predict VO2max. Research Quarterly for Exercise
and Sport. 75:3, 337-342.
• CareFusion Corporation. (2014). Vmax Encore Metabolic Cart. Retrieved
from www.carefusion.com
• Innovision ApS. (2014). Innocor. Retrieved from www.innovision.dk
• Stringer, W. Hansen, J. Wasserman, K. (1997). Cardiac output estimated
noninvasively from oxygen uptake during exercise. J Appl Physiol
82:908-912.
• Welch, HG. Pedersen, PK. (1981). Measurement of metabolic rate in
hyperoxia. J Appll Physiol Respir Environ Exerc Physiol. Sep; 51(3):
725-31.

14. 15
20
25
30
35
40
45
50
55
50 100 150 200 250 300
VO2(ml/kg/min)
Workload (Watts)
Vmax
Innocor
Predicted VO2
Figure 6: Relative VO2 (ml/kg/min) vs. Workloads (Watts)
VO2 = (Watts (Watts)/ Bodyweight (kg) × 10.8) + 7ml/kg/min