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Juerg Feldmann

Fortiori Design LLC
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Posts: 1,530
 #1 
I will be back later with some thoughts on the VO2 max and respiration.
 . The main reason is, that with MOXY  now shipping out today to many different open minded  groups, we  will start a new chapter in practical applications and training ideas.
 I like to warm you up a little bit with some  short abstracts on the  use of NIRS  an d than with a " Bomb " shell on some critical questions on how we may use NIRS to  kill a great idea or how we can use NIRS to move a step ahead to a long overdue critical view on the classical models of anaerobe, lactate threshold and VO2  max ideas.
  Here first a fun abstract and the  start of our new  direction with a great critical paper by T.D. Noakes. in pdf  form as a good night lecture as you may loos  sleep after reading this paper.
 

Human respiratory muscle blood flow measured by near-infrared spectroscopy and indocyanine green

  1. Jordan A. Guenette1,
  2. Ioannis Vogiatzis2,3,
  3. Spyros Zakynthinos2,
  4. Dimitrios Athanasopoulos2,3,
  5. Maria Koskolou3,
  6. Spyretta Golemati2,
  7. Maroula Vasilopoulou2,
  8. Harrieth E. Wagner4,
  9. Charis Roussos2,
  10. Peter D. Wagner4, and
  11. Robert Boushel5,6

+ Author Affiliations

  1. 1School of Human Kinetics, The University of British Columbia, Vancouver, British Columbia, Canada; 2Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, “M. Simou and G. P. Livanos Laboratories,” National and Kapodistrian University of Athens, Athens, Greece; 3Department of Physical Education and Sport Sciences, National and Kapodistrian University of Athens, Athens, Greece; 4Department of Medicine, University of California-San Diego, La Jolla, California; 5Department of Exercise Science, Concordia University, Montreal, Quebec, Canada; and 6Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, Denmark
  1. Address for reprint requests and other correspondence: J. A. Guenette, Health and Integrative Physiology Laboratory, Univ. of British Columbia, 6108 Thunderbird Blvd., Vancouver, BC, Canada V6T-1Z3
  • Submitted 30 October 2007.
  • Accepted 17 January 2008.

Abstract

Measurement of respiratory muscle blood flow (RMBF) in humans has important implications for understanding patterns of blood flow distribution during exercise in healthy individuals and those with chronic disease. Previous studies examining RMBF in humans have required invasive methods on anesthetized subjects. To assess RMBF in awake subjects, we applied an indicator-dilution method using near-infrared spectroscopy (NIRS) and the light-absorbing tracer indocyanine green dye (ICG). NIRS optodes were placed on the left seventh intercostal space at the apposition of the costal diaphragm and on an inactive control muscle (vastus lateralis). The primary respiratory muscles within view of the NIRS optodes include the internal and external intercostals. Intravenous bolus injection of ICG allowed for cardiac output (by the conventional dye-dilution method with arterial sampling), RMBF, and vastus lateralis blood flow to be quantified simultaneously. Esophageal and gastric pressures were also measured to calculate the work of breathing and transdiaphragmatic pressure. Measurements were obtained in five conscious humans during both resting breathing and three separate 5-min bouts of constant isocapnic hyperpnea at 27.1 ± 3.2, 56.0 ± 6.1, and 75.9 ± 5.7% of maximum minute ventilation as determined on a previous maximal exercise test. RMBF progressively increased (9.9 ± 0.6, 14.8 ± 2.7, 29.9 ± 5.8, and 50.1 ± 12.5 ml·100 ml−1·min−1, respectively) with increasing levels of ventilation while blood flow to the inactive control muscle remained constant (10.4 ± 1.4, 8.7 ± 0.7, 12.9 ± 1.7, and 12.2 ± 1.8 ml·100 ml−1·min−1, respectively). As ventilation rose, RMBF was closely and significantly correlated with 1) cardiac output (r = 0.994, P = 0.006), 2) the work of breathing (r = 0.995, P = 0.005), and 3) transdiaphragmatic pressure (r = 0.998, P = 0.002). These data suggest that the NIRS-ICG technique provides a feasible and sensitive index of RMBF at different levels of ventilation in humans.


Juerg Feldmann

Fortiori Design LLC
Registered:
Posts: 1,530
 #2 
Here is a beautifully examples of many we will show, where the " classical " search for lactate threshold and VO2 max reactions terribly failed but NIRS information clearly indicate a shift in oxygenation reactions,.
 Many people spent lot's of money, either by buying hypoxic equipment or going  to altitude.
 Classical parameters like lactate threshold and VO2 max are of very limited, if of any value to be used  for any information on training effect.
 Once we overcome the historical view, about the problme of anaerobe, lactat threshold, VO2 max and more  and we open up for a new  look at oxygenation per see, we may in fact get many more and  better answers on questions we now cosmetically try o  change to be able to justify  what we do since 100 years.
 This  study, which is fixed on the idea , that there is a lactate threshold an date idea, that VO2 max is an indicator of what ever, show an very interesting hint on where we may be able to move towards, when we openly embrace a different idea of looking at MOXY.
 

Discrepancy between cardiorespiratory system and skeletal muscle in elite cyclists after hypoxic training

Ryotaro Kime12*, Trine Karlsen3, Shoko Nioka1, Gwen Lech1, Ørjan Madsen3, Rolf Sæterdal, Joohee Im1, Britton Chance1 and James Stray-Gundersen34

Author Affiliations

1 Department of Biochemistry and Biophysics, University of Pennsylvania, USA

2 Department of Preventive Medicine and Public Health, Tokyo Medical University, Tokyo, Japan

3 Norwegian Olympic Committee and Confederation of Sports, Oslo, Norway

4 Norwegian University of Sport and Physical Education, Oslo, Norway

For all author emails, please log on.

Dynamic Medicine 2003, 2:4 doi:10.1186/1476-5918-2-4


The electronic version of this article is the complete one and can be found online at: http://www.dynamic-med.com/content/2/1/4


Received:7 February 2003
Accepted:22 August 2003
Published:22 August 2003

© 2003 Kime et al; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.

 

Abstract

Background

The purpose of this study was to determine the effects of hypoxic training on the cardiorespiratory system and skeletal muscle among well-trained endurance athletes in a randomized cross-over design.

Methods

Eight junior national level competitive cyclists were separated into two groups; Group A trained under normoxic condition (21% O2) for 2 hours/day, 3 days/week for 3 weeks while Group B used the same training protocol under hypoxic condition (15% O2). After 3 weeks of each initial training condition, five weeks of self-training under usual field conditions intervened before the training condition was switched from NT to HT in Group A, from HT to NT in Group B. The subjects were tested at sea level before and after each training period. O2 uptake ([1476-5918-2-4-i1]O2), blood samples, and muscle deoxygenation were measured during bicycle exercise test.

Results and Discussion

No changes in maximal workload, arterial O2 content, [1476-5918-2-4-i1]O2 at lactate threshold and [1476-5918-2-4-i1]O2max were observed before or after each training period. In contrast, deoxygenation change during submaximal exercise in the vastus lateralis was significantly higher at HT than NT (p < 0.01). In addition, half time of oxygenation recovery was significantly faster after HT (13.2 ± 2.6 sec) than NT (18.8 ± 2.7 sec) (p < 0.001).

Conclusions

Three weeks of HT may not give an additional performance benefit at sea level for elite competitive cyclists, even though HT may induce some physiological adaptations on muscle tissue level.

Juerg Feldmann

Fortiori Design LLC
Registered:
Posts: 1,530
 #3 
For  readers, digesting some of T.D. Noakes interesting argumentation, here a nice  study, who may  in fact show , where and why MOXY, if used independent from VO2 max and lactate threshold, may give you some very nice feed-backs on what is going on.
 

Effects of short-term endurance training on muscle deoxygenation trends using NIRS.

Source

Faculty of Kinesiology, University of New Brunswick, Fredericton, Canada. pneary@unb.ca

Abstract

PURPOSE:

This study examined changes in cardiorespiratory responses and muscle deoxygenation trends to test the hypothesis that both central and peripheral adaptations would contribute to the improvements in VO(2max) and simulated cycling performance after short-term high-intensity training.

METHODS:

Eight male cyclists performed an incremental cycle ergometer test to voluntary exhaustion, and a simulated 20-km time trial (20TT) on wind-loaded rollers before and after training (60 min x 5 d x wk(-1) x 3 wk at 85-90% VO(2max). Near-infrared spectroscopy (NIRS) was used to evaluate the trend in vastus medialis hemoglobin/myoglobin deoxygenation (Hb/Mb-O(2) during both tests pre- and post-training.

RESULTS:

Training induced significant increases (P </= 0.05) in maximal power output (367 +/- 63 to 383 +/- 60 W), VO(2max) (4.39 +/- 0.66 to 4.65 +/- 0.57 L x min(-1)), and maximal O(2) pulse (22.7 +/- 3.2 to 24.6 +/- 2.8 mL O(2) x beat(-1)) during the incremental test, but maximal muscle deoxygenation was unchanged. 20TT performance was significantly faster (27:32 +/- 1:43 to 25:46 +/- 1:44 min:s; P </= 0.05) after training without a significant increase (P > 0.05) in the VO(2) (4.02 +/- 0.52 to 4.04 +/- 0.51), heart rate (176 +/- 9 to 173 +/- 8 beats x min ) or O pulse (22.4 +/- 3.2 to 23.5 +/- 2.8 mL O(2) x beat(-1)). However, mean muscle deoxygenation during the 20TT was significantly lower after training (-550 +/- 292 to -707 +/- 227 mV, P </= 0.05), and maximal deoxygenation showed a trend toward significance (-807 +/- 344 to -1,009 +/- 331 the P = 0.08), suggesting a greater release of oxygen from Hb/Mb-O(2) via the Bohr effect.

CONCLUSION:

The significant improvement in themax) induced by short-term endurance training in well-trained cyclists was due primarily to central adaptations, whereas the simulated 20TT performance was enhanced due to localized changes in muscle oxygenation.


What is missing is differenceon  and the respiratory  action endurancee between theT and the short term therenace.
. homeostheis is a need for homeostaissis  throughout teh systems and not in isolation.

Juerg Feldmann

Fortiori Design LLC
Registered:
Posts: 1,530
 #4 
And here another interesting idea. Ventilatory threshold and NIRS.
 What this plus many other studies show is, that the NIRS ( MOXY ) trend if properly applied outside the " classical" idea of forcing a VO2  max or % and forcing a threshold of any kind based on mathematical formulas but simply look at NIRS trend may open a very cheap and simple version for testing  people and  designing a training intensity  protocol TIP based on a proper physiological timed step test idea.
Int J Sports Med. 2005 Sep;26(7):576-82.

Respiratory muscle deoxygenation and ventilatory threshold assessments using near infrared spectroscopy in children.

Source

EA 3300 APS et Conduites Motrices: Adaptations et Réadaptations, Faculté des Sciences du Sport, Université de Picardie Jules Verne, Amiens, France.

Abstract

The aim of this study was to assess respiratory muscles deoxygenation and to determine ventilatory threshold using near infrared spectroscopy (NIRS) in children during incremental cardiopulmonary exercise. Fourteen healthy children with a mean +/- SD age of 12.8 +/- 1.4 yrs performed an incremental exercise test on a cycle ergometer. NIRS was used to assess deoxygenation of the respiratory muscles. Ventilatory parameters (oxygen uptake, carbon dioxide production, and ventilation minute), power output, and tissue saturation (StO2) were measured. Ventilatory threshold was determined by the two following methods: the V-slope method which corresponds to the breakpoint in VCO2 as a function VO2 relationship (VT(V-slope)) and the NIRS method which corresponds to the point of rapid fall in StO2 (VT(nirs)). During exercise, the respiratory muscles deoxygenated as the exercise intensity increased. StO2 decrease progressively until an abrupt decrease was observed. No significant differences were observed between cardiorespiratory variables corresponding either to VT(V-slope) or to VT(nirs). The two methods showed a good agreement (data were inside the 95 % confidence interval). Likewise, a significant relationship was found between VT(V-slope) and VT(nirs) for each parameter measured (r = 0.87 to 0.94, p < 0.001). We concluded that respiratory muscles deoxygenate during incremental exercise in children and that ventilatory threshold could be determined by NIRS.

Juerg Feldmann

Fortiori Design LLC
Registered:
Posts: 1,530
 #5 
Here is  one of the reasons why  NIRS MOXY  can't tell you the trend optimal in oxygenation.
 The problem is in the design of the protocol. We discussed this in depth a while back.
 The assessment or protocol  often decides the outcome of the physiological results.
 The classical idea of 3 min step test  to assess anything has to be reviewed.
 For a " VO2 max " test it is  of little value.
 So when we assess we are not interested in maximal  values but in the  trend and the  development of the physiological system  on how they react on increase in workload. Do we see some specific reactions when looking at  all the different systems.
 Than we compare where the ultimate change  will show up first , being in the muscles, who perform the task.
 The survival idea is simple. Do you like to run  or do you like to breath of pump?
 Luckily for most of us, the  peripheral performance by muscles is on the lowest priority list for survival so that feedback loops  from and to the brain will reduce the O2 demand in the working muscles. ( Steeling O2 ) from vital organs.


 Here a picture  and you  make your own decision.
  1 pic shows a  3 min st3ep test one a 5 min step test and one shows our IPAHR 5/1/5.
 Now look at trends and you decide, where you can see  the bodies outreach  to try to re-establish a decent  energy balance, and where it is moving out of balance.

 2 of the test are from our friend from Slovenia and I will be back later as he combined this with lactate and VO2  equipment, which is a great way to add additional information to the trend reaction.  It is all about feedback in both directions. See our very old  picture from many years back

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