The Importance of Testing and Measuring Maximal Steady State

Robert A. Robergs, Ph.D., FASEP, EPC

Exercise Physiology Laboratories, Exercise Science Program, University of New Mexico

• Endurance athlete laboratory testing has traditionally been constrained to VO2max, metabolic thresholds and economy.

• Mounting evidence that metabolic threshold under-represents the average intensity during endurance exercise performance.

• Quantifying the true maximal steady state differs to a metabolic threshold gained from incremental exercise testing.

• Maximal steady state testing is essential, but there are minimal guidelines and recommendations on this procedure.

Background

Problems With VO2max

• What is VO2max?

• How is VO2max quantified?

• What data processing method should be used?

•How do we deal with mode-specificity?

• How do we deal with protocol specificity?

• What is the risk of maximal exercise testing for different populations?

Data Example

Treadmill VO2max Test

0 1 2 3 4 5 6 7 8 9 100

10

20

30

40

50

60

70

Time (min)

VO

2 (

ml/

kg/m

in)

6 6.5 7 7.5 8 8.5

0 0 0 0 0 0 1.5 3 4.5 6

mi/Hr

%grade

Cycle Ergometry VO2max Test

-1 0 1 2 3 4 5 6 7 8 9 10 11 12 130.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

recovery

rest

VO2max = 3.28 L/min

30 Watts 30 Watt/min ramp240 WattsTime (min)

VO

2 (

L/m

in)

Maximal Steady State • Highest intensity at steady state.

• Most similar to average performance intensity for 30 to 90 min.

• Totally dependent on muscular and cardio-respiratory endurance

• More safe for “at risk” subjects.

• Simple data processing.

• Provides a valid measure for training programs.

What Maximal Steady State Is Not!

0 2 4 6 8 10 1215

20

25

30

35

40

45

VT

Time (min)

VE

/VO

2 &

VE

/VC

O2

VE/VO2

VE/VCO2

Incremental Metabolic Threshold (LT, VT, OBLA)

0 2 4 6 8 10 120

1

2

3

4

5

6

8.43 min

Time (min)

Blo

od

Lac

tate

(m

mo

l/L

)

130 135 140 145 150 1552.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

Watts

Blo

od

Lac

tate

(m

mo

l/L

)

Measuring Maximal Steady StateOption 1:

VO2max test.

Determine VT or LT.

Calculate intensity at 110% VT or LT.

After subject has recovered,

Exercise for 15 min at 110 %VT or LT.

If variables (HR, VE, VO2) remain stable over time, increment 10 Watts or 0.25 mi/Hr and repeat.

Continue until physiological variables no longer reflect steady state.

Option 2:

Exercise and increase intensity over time until RER is close to 1.0.

Exercise for 15 min at this intensity.

If variables remain stable over time, increment 10 Watts or 0.25 mi/Hr and repeat.

Continue until physiological variables no longer reflect steady state.

Best to allow subject to recover for 5 - 10 min between bouts.

Maximal Steady State = highest steady state intensity

Example Data

0 5 10 15 20 2560

80

100

120

140

160

Time (Min)H

eart

Rat

e (b

/min

)

132 Watts142 Watts

152 Watts

0 5 10 15 20 250

20

40

60

80

100

Time (min)

Ven

tila

tio

n (

L/m

in)

Running @ 9.0 mi/Hr

0 1 2 3 4 5 6 7 8 9 100

25

50

75

100

125

Time (min)

VE

(L

/min

)

0 1 2 3 4 5 6 7 8 9 10

100

115

130

145

160

175

190

Time (min)

Hea

rt R

ate

(b/m

in)

Thank you

www.unm.edu/~rrobergs