Sign up Latest Topics

  Author   Comment  

Avatar / Picture

Development Team Member
Posts: 15

Yesterday was the 2nd Thurs night race I was able to wear the MOxy during. These races I put forth an effort of ~ 8 (out of 10) and drop to about a ~7 near the end. As opposed to what I put forth during a Sunday race (which I haven't gotten any data for yet) where I'll put forth a 10. This Thursday there was a light rain at the start of the race, so I hope that the TI watch is water resistant at least a little. I wasn't too worried about the sensor since it is under my shorts and the shield.

This time I've graphed the elevation on the same graph for easier comparison... guess I didn't really think about SportTracks including that data also before.

Noise levels seem about the same, even with the upgraded device.  This time was cloudy the entire race, but the previous was fairly sunny I think, but either way, I was in the woods most of the time. 

As usual the data seems to follow what is expected, dropping on the uphills, and rising on the recovery downhills. Interesting to note is that I still didn't get below 20% even though I felt like my legs were weak... but should have been recovered well enough since I hadn't exercised in a few days.

The paragraph overlays both WTR races together.  Keep in mind that the x-axis is time, from when the sensor was started and stopped, so there is a slight offset b/c I started the sensor earlier before the race.  It actually works out okay since you can easily see how well everything matches. 

When looking at this, I notice that SmO2 was nearly identical between both races, yet HR was lower for the most recent one (15).  Generally comparing, I’d say that I felt ‘better’ during the first race (11).  So how do I interpret this?  Well, since my avg speed and SmO2 were nearly identical, I would say that it makes sense that I should be more fit during the latter race, and thus be able to put forth the same muscular effort at a lower HR expenditure.  The questions are, then, what was the limiting factor? Was I interpreting my effort level by my heart/breathing or by my muscle fatigue?  Does my heart determine how hard my legs can push, or does how hard my legs push determine how hard my heart works?  That’s a hard question that I don’t know answer.  I would say that for the latter race (15), I mentally didn’t feel up for racing that night compared to the previous (11).  Even though I feel like both were at an effort level of 8, the psychological aspect shifts that scale.  If I would have felt as motivated, would my HR have been higher, or my SmO2 lower? 

Another factor could have been temperature.  The 1st race (11) had temp of 93° while the 2nd was 72°.  So perhaps it shows how much harder your heart works, at the same muscular level, when it’s hot out.

Also, I only had 1 day of recovery before the 1st race, but had 3 before the 2nd.  Maybe my heart hadn’t recovered enough for the 1st race, even though my legs had.  My typical response would be that I could have tried harder during the 2nd race, to get my HR higher.  The more fit I am, the higher I should be able to get my HR.  My legs determine my pace, so if I would have been mentally motivated, I would have pushed my HR higher, and hopefully increased my speed, but would my Sm02 have dropped? 

There is one more Thursday night race for the year, so we’ll have to see how I feel next week!

Attached Images
Click image for larger version - Name: WTR_Graph_2012-09-06.JPG, Views: 37, Size: 94.06 KB  Click image for larger version - Name: WTR_compare_Graph_2012-09-06.JPG, Views: 35, Size: 123.59 KB  Click image for larger version - Name: temp.JPG, Views: 24, Size: 11.08 KB 

Attached Files
xlsx 15_-_MTB_-_WTR_-_2012-09-06.xlsx (420.18 KB, 18 views)

Larry Flessland

Fortiori Design LLC
Posts: 38

There are several things that contribute to noisy SmO2 readings.  I was talking to Stu about this and he mentioned that we need to isolate physiology from the sensor.


On the sensor side we are trying to eliminate things that cause electrical noise like interference from the radio.  If a detector or LED is starting to degrade, that could cause noisy readings but we don’t have a way to detect that yet.


Physiology can make the readings appear noisy such as the measurement site, type of exercise and sensor placement.  See the post on noisy readings and sensor placement in Tech Support on this forum:

Juerg Feldmann

Fortiori Design LLC
Posts: 1,530
Some nice loud thinking  on the results of the MTB race.
 One of the nice parts is : Limiter and is the heart limiting the  leg or the leg the heart. That is the key questions not just , when trying to make NIRS interpretations but as well when choosing any training stimulation.  Below you will see some  pictures on that issue from our European seminar  from the last few years on NIRS and oxygenation in combination with training.

The key is , when assessing a future MOXY customer or any NIRS user , to  exactly  find that out. Who or what system is limiting  further performance and what system or systems try to compensate. NIRS and moxy  will be  the  bio marker of choice once you have this answer. We are working on that issue since 25 + years and  for now arrived on the so called IPAHD assessment  IPAHD standing for individual physiological assessment of homeostasis disruption.
So once you have your limiter you can use NIRS to actually  define  different training ideas.
 Remember that the question for endurance is two folds.
Harre ( former DDR  1970 )
So as long we do not know the limiter we always will have the above questions. I may show depending on the ongoing discussion some  real live data's from some world cup races and other events like live testing  from a rowing boat on the water , where we watched on the shore wireless live the  oxygenation trend  in the athlete.
Here just to finish this thoughts in some pictures.

Some hints to  some of the physiological noise mentioned. If using vastus lateralis , which is a very good choice for cycling , than you have to watch carefully , that you have  R and T on the actual muscle belly. If you move one or the other over the ITB ( tensor fascia latea  you will have much more noise.

Previous Topic | Next Topic

Quick Navigation:

Easily create a Forum Website with Website Toolbox.

HTML hit counter -