Your Metabolic
or
Mechanical Efficiency (ME)
links your sustainable power to your actual performance work rate,
velocity or speed. The
better the ME the greater the achieved velocity.
Probably the best predictor of endurance performance is the
power you can produce at Lactate Threshold.
Your ME is
determined, more specifically, by measuring the volume of oxygen
taken up by your working muscles at a given sub-threshold exercise
intensity. For example, when cycling on a bike ergometer, your VO2
consumption at a standard power output can be used for comparison. A
reduced volume of oxygen at the same power output in
repeated testing would suggest
an improved oxygen economy and improved performance potential.
At
the Fit Stop we measure ME during the Cardio-Metabolic Profile by
comparing your actual VO2 measured at lactate threshold with the VO2
predicted through calculations using the power output. We also
measure Efficiency and Economy during a 20-minute sub-max exercise
test called the Exercise Economy Profile. This test is conducted a
couple of days after the C-M Profile and requires performing a cycle
or treadmill test for 20 minutes at 80% of your VO2Max.
Outcomes from the EE Profile include:
GE = The
Gross Mechanical
Efficiency
is the ratio of work accomplished to energy expended which describes
whole body efficiency. Normal fit cyclists are typically around 20%
while Pro Riders average closer to 25%.
EE =
Cycling Economy
or Running Economy refers to the actual power output generated at a
cost of 1 L of oxygen (L= Liter). Highly trained amateurs cyclists
generate approximately 75 W/L/min where as the pros are measured in
the 85 W/L/min range.
VO2 drift = is commonly
referred to as the
VO2 slow component.
Endurance performance can be enhanced by training to decrease the
magnitude of the slow component. World class cyclists show increases
of VO2 less than 130 ml over 20 minutes at a work rate of 80% of VO2
max. Unfit or normal fit cyclists will show 3-4 times this amount of
drift for 20 minutes at the same relative intensity.
See
sample report click here
Example of the
20-minute Cycling Economy Profile
Studies have shown that with the proper training we can expect improvement in all 3 categories (i.e.,
aerobic capacity, metabolic fitness & ME) but not at the same
rate. VO2
usually plateaus after 1 year
of training. Lactate
threshold plateaus usually in about 3-4
years while ME continues to improve even after 4
years of systematic training.
Copyright © 2000-05 The Fit Stop Human
Performance Lab. All rights reserved.
Revised:
September 17, 2006
.
Located in Carlsbad, CA Tel: (760) 634-5169
e-mail us