Folks,
here is a compilation of answers to the following email request I had sent:
see below for replies
>I was wondering if anyone could offer me some help with our road cycling
>testing protocol.
>
>We take a blood lactate profile of cyclists on a kingcycle ergometer. It is
>an air braked unit which the cyclist places their own bike on. The unit
>calibrates for the cyclists back wheel drag. The unit has been found to
>correlate to a calibration rig within 1% tolerance but I suspect there is
>variation in reality.
>
>The protocol we use is for male cyclists:
>
>start at about 150 watts and increase by 30 watts every 3 minutes whereby
>taking a blood lactate sample. The tests goes on until the athlete decides
>to stop.
>
>We used to stop once a reasonable indication of threshold was obtained but
>we continue now to look at lactate tolerance.
>We used to also sample VO2 towards the end of the test but these days we
>only do it once per year.
>
>I would be interested if anyone could point out any flaws in our approach,
>perhaps if people could contrast with their own protocol, if there is an
>accepted protocol that I am ignorant to or just any advice they could give
>us about how they set their testing up.
>
>In addition to this we take skinfolds, height and weight.
>
>I am interested how some people might set workload according to mass,
>perhaps if anyone is using economy and how they are administering the
>protocol.
>
>If a power to weight figure is used how is this done, maximum power at the
>end of a lactate profile? A maximum power over a 10-30 sec sprint or
perhaps
>even power at aerobic threshold (crossover point of aerobic to anaerobic
>metabolism)?
>
>Thank you in advance for any help you can give me. I will collate any
>responses and distribute once permission is granted.
>
>cheers
>
>
Richard stern
accordingly, i use what ever i have at my disposal (e.g.,
computrainer/axiom) and retrofit the bike with accurate power measuring
equipment (e.g., srm, power tap). (i've validated more than several power
taps against srm, and found the tolerances very close, with an r2=0.99, and
the power tap underestimating c.f., srm by ~ 2% at power > 100 W -- due i
believe to frictional losses in drive train).
i train / test a fair range of cyclists (e.g., 4th cat to pro's) but i base
starting power on where i estimate they are likely to finish (e.g., a 2nd
cat in season should go around 400W), and, therefore, start the test at a
level that will result in a 10 - 20 minute protocol. the ramp rate that i
use is 15W.min-1 for women, 20 W.min-1 for elite men, and 25W.min-1 for
non-elite men. Once i have a baseline figure i generally use the same
starting point for subsequent tests. I test on regular basis (e.g., every
month)
I urge the cyclust to continue as much as possible, and when they can no
longer keep up with the desired output they either stop or i tell them to
stop. i average the last minute power output (the highest average?), and
term that maximal aerobic power. i believe the bcf use the same protocol.
i do not collet expired respiratory gases (don't hav e the equipment!), and
nor do i bother with lactate sampling. i've found that the changes in max.
aerobic power always track with change sin vo2max or power @ TT intensity,
and changes in lactate threshold.
depending on the type of cyclist (e.g., track endurance, road, MTB, TT,
elite, non-elite) will depend on what sort of power to mass ratio i use (if
any). with elite i tend to use power to mass ^0.67 (if they are UK based),
or power to mass ^0.7 (if US based, although i think cycling usa use a
30W.3min-1 ramp rate, possibly in a discontinuous fashion). with TTers i
just tend to look at absolute power, and mtbers power/mass.
Shaun Wallace
With most "trainers", not enough importance has been placed on the inertia,
probably because of the inconvenience of the mass it usually involves. The
inertia severely affects a riders ability to produce power without fatigue.
Not sure whether we just "got lucky", or whether our bodies have adapted to
the inertia of the body &bike as we ride.
On commercial trainers i will help this situation by using a very big gear,
and often having to reduce the drag (taping over fan blades, removing fans
etc) to maintain a realistic drag at the increased wheel speed.
I'm sure the king cycle is more elaborate, and hopefully this issue has been
addressed so that the ergonomics are realistic.
You'd mentioned relating workload to mass, however for cycling this is not
suitable as most of the drag is from wind resistance ... more proportional
to
frontal area.
So perhaps link worload to a square of height, or perhaps better still to
"weight/height". Even these are only rough, and don't allow for the
Coeficient of drag from the differing positions.
If you really want to interpret a power output you'd have to have the rider
cycle his bike on the road with a power-measuring device (Tune hub, SRM etc)
and draw a chart correlating power developed to actual speed.
Gregg Fuhrman
I am a Physical Therapist in Milwaukee Wisconsin, USA and an avid cyclist. A
colleague of mine at Marquette University forwarded to me the e-mail you
posted regarding a cycle ergometer testing protocol for lactate testing. I
have a couple of observations:
1] If the cyclists are skilled, starting at 150W is probably good, but for a
novice or inexperienced cyclist, starting at 100W may be more appropriate.
2] Other protocols I have seen use 20-25W increments for increases at
workloads--I don't have any other reasons for this.
3] If you interested in more of a cycling efficiency test, the 3 min stages
are appropriate as it will give the cyclist plenty of time to reach steady
state. However, if you are looking more at maximum performance levels, 1.5 -
2.0 min stages may be more realistic to reach max without as much peripheral
muscle fatigue.
4] I also think many of the tests teams use are non-published and used to
establish benchmarks for athletes training. No published norms available.
5] Most recently, coaches and athletes are expressing power outputs in watts
per kilogram body weight at threshold and maximum. Chris Carmichael, Lance
Armstrongs coach is using this approach in training and testing with riders
using the SRM Powermeter on their road machines. To find out more, go to
www.ridefast.com
to see articles and to contact the Carmicael staff; they are a very helpful.
6] Another separate test of pure anaerobic power, completely separate from
efficiency or max testing would be the Wingate Power test. The resistances
for this test are based on a riders weight.
Dr Asker Jeukendrup
The protocol we use is very similar. We start at 95W and the workload is
increased every 3 min by 35W. The only reason we have included the very low
workloads is to obtain more submaximal information. As you know I work
closely with several professional cyclists and it is my experience that the
changes in the submaximal values are more related to performance than the
changes in maximal values (in already trained individuals). We succesfully
use this test in both World Class cyclists and novice cyclists. I don't
believe in increasing workload based on weight because fitness and talent
are much greater factors than weight and these are difficult to take into
account.
The first 3 min of any graded exercise test are usually not very informative
(this is when no warm-up is used). The economy during the first stage is
usually a lot lower compared to later stages. By starting at a lower
workload there is a greater chance that you get better values for oxygen
uptake or substrate utilisation at 135W (or 150W).
The big problem with protocols like these is that the test may take very
long in very well-trained cyclists. Especially professional cyclists may
reach a maximum of 500W with this protocol and this means they are on the
bike for almost 45 min.
Although 5 min stage durations may give you a more accurate reflection of
lactate concentrations in the muscle, the test duration increases so much
that maximal values will be reduced. The studies by Padilla et al (2000ab)in
professional cylists used 4 min stages. Some of these guys had to ride for
an hour to get to their maximum!
When using shorter stages (1-2 min) you may obtain slightly higher VO2max
values but the lactate concentrations at submaximal stages do not reflect
muscle lactate.
Finally I think it is very important to continue these tests to exhaustion.
Not only to get a value of lactate tolerance but see changes in maximal
lactate during the season. Decreased submaximal as well as maximal lactate
values can be indicative of
overtraining (Jeukendrup et al 1992, 1994)
I think that the protocol you are using is a good compromise between getting
usable submaximal values (lactate, oxygen uptake, efficientie) and maximal
values (VO2max).
Finally, for all cycling science fans: there is a special issue coming up in
Sports Medicine dedicated to cycling. I believe it is the May issue.
also see
http://www.humankinetics.com/products/showproduct.cfm?isbn=0736003266
regards
Danny Rutar
National Coaching and Training Centre
University Of Limerick
Ireland
Ph: +353 6120289 FX: +35361338174
Email: danny.rutar@ul.ie
---------------------------------------------------------------
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---------------------------------------------------------------
here is a compilation of answers to the following email request I had sent:
see below for replies
>I was wondering if anyone could offer me some help with our road cycling
>testing protocol.
>
>We take a blood lactate profile of cyclists on a kingcycle ergometer. It is
>an air braked unit which the cyclist places their own bike on. The unit
>calibrates for the cyclists back wheel drag. The unit has been found to
>correlate to a calibration rig within 1% tolerance but I suspect there is
>variation in reality.
>
>The protocol we use is for male cyclists:
>
>start at about 150 watts and increase by 30 watts every 3 minutes whereby
>taking a blood lactate sample. The tests goes on until the athlete decides
>to stop.
>
>We used to stop once a reasonable indication of threshold was obtained but
>we continue now to look at lactate tolerance.
>We used to also sample VO2 towards the end of the test but these days we
>only do it once per year.
>
>I would be interested if anyone could point out any flaws in our approach,
>perhaps if people could contrast with their own protocol, if there is an
>accepted protocol that I am ignorant to or just any advice they could give
>us about how they set their testing up.
>
>In addition to this we take skinfolds, height and weight.
>
>I am interested how some people might set workload according to mass,
>perhaps if anyone is using economy and how they are administering the
>protocol.
>
>If a power to weight figure is used how is this done, maximum power at the
>end of a lactate profile? A maximum power over a 10-30 sec sprint or
perhaps
>even power at aerobic threshold (crossover point of aerobic to anaerobic
>metabolism)?
>
>Thank you in advance for any help you can give me. I will collate any
>responses and distribute once permission is granted.
>
>cheers
>
>
Richard stern
accordingly, i use what ever i have at my disposal (e.g.,
computrainer/axiom) and retrofit the bike with accurate power measuring
equipment (e.g., srm, power tap). (i've validated more than several power
taps against srm, and found the tolerances very close, with an r2=0.99, and
the power tap underestimating c.f., srm by ~ 2% at power > 100 W -- due i
believe to frictional losses in drive train).
i train / test a fair range of cyclists (e.g., 4th cat to pro's) but i base
starting power on where i estimate they are likely to finish (e.g., a 2nd
cat in season should go around 400W), and, therefore, start the test at a
level that will result in a 10 - 20 minute protocol. the ramp rate that i
use is 15W.min-1 for women, 20 W.min-1 for elite men, and 25W.min-1 for
non-elite men. Once i have a baseline figure i generally use the same
starting point for subsequent tests. I test on regular basis (e.g., every
month)
I urge the cyclust to continue as much as possible, and when they can no
longer keep up with the desired output they either stop or i tell them to
stop. i average the last minute power output (the highest average?), and
term that maximal aerobic power. i believe the bcf use the same protocol.
i do not collet expired respiratory gases (don't hav e the equipment!), and
nor do i bother with lactate sampling. i've found that the changes in max.
aerobic power always track with change sin vo2max or power @ TT intensity,
and changes in lactate threshold.
depending on the type of cyclist (e.g., track endurance, road, MTB, TT,
elite, non-elite) will depend on what sort of power to mass ratio i use (if
any). with elite i tend to use power to mass ^0.67 (if they are UK based),
or power to mass ^0.7 (if US based, although i think cycling usa use a
30W.3min-1 ramp rate, possibly in a discontinuous fashion). with TTers i
just tend to look at absolute power, and mtbers power/mass.
Shaun Wallace
With most "trainers", not enough importance has been placed on the inertia,
probably because of the inconvenience of the mass it usually involves. The
inertia severely affects a riders ability to produce power without fatigue.
Not sure whether we just "got lucky", or whether our bodies have adapted to
the inertia of the body &bike as we ride.
On commercial trainers i will help this situation by using a very big gear,
and often having to reduce the drag (taping over fan blades, removing fans
etc) to maintain a realistic drag at the increased wheel speed.
I'm sure the king cycle is more elaborate, and hopefully this issue has been
addressed so that the ergonomics are realistic.
You'd mentioned relating workload to mass, however for cycling this is not
suitable as most of the drag is from wind resistance ... more proportional
to
frontal area.
So perhaps link worload to a square of height, or perhaps better still to
"weight/height". Even these are only rough, and don't allow for the
Coeficient of drag from the differing positions.
If you really want to interpret a power output you'd have to have the rider
cycle his bike on the road with a power-measuring device (Tune hub, SRM etc)
and draw a chart correlating power developed to actual speed.
Gregg Fuhrman
I am a Physical Therapist in Milwaukee Wisconsin, USA and an avid cyclist. A
colleague of mine at Marquette University forwarded to me the e-mail you
posted regarding a cycle ergometer testing protocol for lactate testing. I
have a couple of observations:
1] If the cyclists are skilled, starting at 150W is probably good, but for a
novice or inexperienced cyclist, starting at 100W may be more appropriate.
2] Other protocols I have seen use 20-25W increments for increases at
workloads--I don't have any other reasons for this.
3] If you interested in more of a cycling efficiency test, the 3 min stages
are appropriate as it will give the cyclist plenty of time to reach steady
state. However, if you are looking more at maximum performance levels, 1.5 -
2.0 min stages may be more realistic to reach max without as much peripheral
muscle fatigue.
4] I also think many of the tests teams use are non-published and used to
establish benchmarks for athletes training. No published norms available.
5] Most recently, coaches and athletes are expressing power outputs in watts
per kilogram body weight at threshold and maximum. Chris Carmichael, Lance
Armstrongs coach is using this approach in training and testing with riders
using the SRM Powermeter on their road machines. To find out more, go to
www.ridefast.com
to see articles and to contact the Carmicael staff; they are a very helpful.
6] Another separate test of pure anaerobic power, completely separate from
efficiency or max testing would be the Wingate Power test. The resistances
for this test are based on a riders weight.
Dr Asker Jeukendrup
The protocol we use is very similar. We start at 95W and the workload is
increased every 3 min by 35W. The only reason we have included the very low
workloads is to obtain more submaximal information. As you know I work
closely with several professional cyclists and it is my experience that the
changes in the submaximal values are more related to performance than the
changes in maximal values (in already trained individuals). We succesfully
use this test in both World Class cyclists and novice cyclists. I don't
believe in increasing workload based on weight because fitness and talent
are much greater factors than weight and these are difficult to take into
account.
The first 3 min of any graded exercise test are usually not very informative
(this is when no warm-up is used). The economy during the first stage is
usually a lot lower compared to later stages. By starting at a lower
workload there is a greater chance that you get better values for oxygen
uptake or substrate utilisation at 135W (or 150W).
The big problem with protocols like these is that the test may take very
long in very well-trained cyclists. Especially professional cyclists may
reach a maximum of 500W with this protocol and this means they are on the
bike for almost 45 min.
Although 5 min stage durations may give you a more accurate reflection of
lactate concentrations in the muscle, the test duration increases so much
that maximal values will be reduced. The studies by Padilla et al (2000ab)in
professional cylists used 4 min stages. Some of these guys had to ride for
an hour to get to their maximum!
When using shorter stages (1-2 min) you may obtain slightly higher VO2max
values but the lactate concentrations at submaximal stages do not reflect
muscle lactate.
Finally I think it is very important to continue these tests to exhaustion.
Not only to get a value of lactate tolerance but see changes in maximal
lactate during the season. Decreased submaximal as well as maximal lactate
values can be indicative of
overtraining (Jeukendrup et al 1992, 1994)
I think that the protocol you are using is a good compromise between getting
usable submaximal values (lactate, oxygen uptake, efficientie) and maximal
values (VO2max).
Finally, for all cycling science fans: there is a special issue coming up in
Sports Medicine dedicated to cycling. I believe it is the May issue.
also see
http://www.humankinetics.com/products/showproduct.cfm?isbn=0736003266
regards
Danny Rutar
National Coaching and Training Centre
University Of Limerick
Ireland
Ph: +353 6120289 FX: +35361338174
Email: danny.rutar@ul.ie
---------------------------------------------------------------
To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://isb.ri.ccf.org/biomch-l
---------------------------------------------------------------