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Juerg Feldmann

Fortiori Design LLC
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Posts: 1,530
 #1 
This is a great  direction and  the future will show for sure many new studies where  muscle biopsies and MOXY reactions will be compared  over time.
.
 The fact, that we can see changes in the O2 dynamic over time   and see, that for example a client can learn to deoxygenate better  and or have a better delivery system alone is an indication, that we may in fact change  O2  dynamic.
 Once we have some clear studies  on  how a FTF  fiber behaves compared with  STF fibers we than have with MOXY a great tool to track potential changes.
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 I use MOXY  after ACL repairs to track the change  over time  , when they can't really load yet optimal and there are some very intriguing changes  to see. So  to finish this  for sure ongoing  question here a great  study , which would support this  ideas. Again  used on Speed skater in Germany .
 The introduction  of MOXY last week in Europe and this coming weeks in European sport seminars and expos  will create an explosion in practical applications all over Europe and we look froward to get many great ideas and info's back to our  starting line.
 Here for you the  short study.

MUSCLE OXYGENATION IN ELITE ICE SPEED SKATERS DURING INCREMENTAL TESTING – ADAPTATION OR ACUTE METABOLIC DEMAND?

 

Authors:

Born, D.P., Lindner, N., Hoppe, M.W., Sperlich, B.

Institution:

University of Wuppertal

Department:

Department of Sports Sciences

Country:

Germany

Abstract text

Introduction Elite long-track ice speed skaters were shown to have a remarkable oxygenation asymmetry between right and left legs quadriceps femoris muscle during cornering as well as the straight sections of the track (Born et al. 2012). Therefore, it can be questioned if chronic adaptations to the constant travelling anti-clockwise rather than the acute metabolic demand leads to the remarkable oxygenation asymmetry between right and left legs quadriceps femoris muscle. Methods 5 female elite German ice speed skaters (60.1±8.1kg, 167±6cm, 20.7±2.6%, VO2max 57.8±5.9 ml/min/kg) performed a 3000m on-ice race simulation on a 400m outdoor track matching the standards for international competitions. Additionally, in a laboratory test all participants cycled at two submaximal workloads (1.6 and 2.0W/kg) for 3min each followed by a ramp test until voluntary exhaustion. During both tests ventilation (VE), oxygen uptake (VO2), and heart rate (HR) were measured continuously with a portable gas analyzer (Cortex Metamax & Polar). Tissue saturation index and blood volume were determined by the concentrations of oxy-, deoxy- and total haemoglobin measured with wireless near-infrared spectroscopy devices (NIRS, Portamon) at both right and left vastus lateralis muscles. Mid-thigh skinfold thickness was determined using a Harpenden caliper (British Indicators Ltd) and body composition using a four-electrode bio-impedance analysis (Tanita Corp.). Results ANOVA revealed significant lower tissue saturation index in right compared to the left quadriceps femoris muscle (p<0.01) during the 3000m on-ice race simulation when comparing 1st, 3rd and last minute. Interestingly, as well, this oxygenation asymmetry was evident during the ergometer test while cycling at submaximal and maximal workloads (p<0.01). In contrast, changes in blood volume revealed no differences between right and left legs quadriceps femoris muscle throughout the 3000m on-ice race simulation (p=0.74) as well as during the cycle ergometer test (p=0.94). Mid-thigh skin fold thickness (p=0.17) and leg muscle mass (p=0.30) revealed no difference between the right and left leg. Discussion & Conclusion During the on-ice race simulation female elite ice speed skaters showed a more pronounced muscle deoxygenation in the right compared to the left legs quadriceps femoris muscle. Since this phenomenon was evident during submaximal and maximal cycling, it can be concluded that the oxygenation asymmetry is more likely due to chronic adaptation rather than the acute metabolic demand of elite ice speed skating.

 

Juerg Feldmann

Fortiori Design LLC
Registered:
Posts: 1,530
 #2 
Recovery  and NIRS.
 Regular readers may remember our take on using and IPAHR in game sports like ice hockey to actually see difference in  players in the recovery.
 Well NIRS is getting more popular by the day and with MOXY many many more people can afford to do some  small case studies like this here.
 
Med Sci Sports Exerc. 2013 May;45(5):869-75. doi: 10.1249/MSS.0b013e31827e0eb6.

Skeletal muscle metabolism in endurance athletes with near-infrared spectroscopy.

Source

Department of Kinesiology, University of Georgia, Athens, GA 30602, USA. jtbriz@uga.edu

Erratum in

  • Med Sci Sports Exerc. 2013 Aug;45(8):1640-1.

Abstract

PURPOSE:

To determine whether near-infrared spectroscopy (NIRS) measurements of muscle mitochondrial function could detect the expected differences between endurance-trained athletes (n = 8) and inactive subjects (n = 8).

METHODS:

Muscle oxygen consumption (mV˙O2) of the vastus lateralis was measured with continuous-wave NIRS using transient arterial occlusions. The recovery rate of mV˙O2 after electrical stimulation was fit to an exponential curve, with the time constant (Tc) used as an index of mitochondrial capacity. Whole-body peak oxygen uptake was determined by indirect calorimetry during a continuous ramp protocol on a cycle ergometer.

RESULTS:

Whole-body peak oxygen uptake values for endurance-trained and inactive controls were 73.5 ± 9.1 and 33.7 ± 5.9 mL·kg·min, respectively (P < 0.001). The recovery rates of mV˙O2 after exercise for endurance training were 18.4 ± 3.2 and 18.8 ± 2.5 s, whereas those for inactive controls were 32.4 ± 5.2 and 34.9 ± 5.9 s for the shallow and deep channels, respectively (P < 0.001 for comparison between groups). Resting mV˙O2 was 0.52%·s ± 0.22%·s for endurance athletes and 0.77%·s ± 0.82%·s for inactive controls (P = 0.42).

CONCLUSIONS:

The recovery rates of mV˙O2 after exercise in endurance athletes were almost twofold faster than inactive subjects measured with NIRS, consistent with previous studies using muscle biopsies and magnetic resonance spectroscopy. Our results support the use of NIRS measurements of the recovery of oxygen consumption to assess muscle oxidative capacity.

Juerg Feldmann

Fortiori Design LLC
Registered:
Posts: 1,530
 #3 
Is it repeatable  ?
 See our take on this from a few years back and what we have as feed backs now:
 
J Appl Physiol (1985). 2012 Jul;113(2):175-83. doi: 10.1152/japplphysiol.00319.2012. Epub 2012 May 10.

Noninvasive evaluation of skeletal muscle mitochondrial capacity with near-infrared spectroscopy: correcting for blood volume changes.

Source

Department of Kinesiology, University of Georgia, Athens, GA 30602, USA. tryan7@me.com

Abstract

Near-infrared spectroscopy (NIRS) is a well-known method used to measure muscle oxygenation and hemodynamics in vivo. The application of arterial occlusions allows for the assessment of muscle oxygen consumption (mVo(2)) using NIRS. The aim of this study was to measure skeletal muscle mitochondrial capacity using blood volume-corrected NIRS signals that represent oxygenated hemoglobin/myoglobin (O(2)Hb) and deoxygenated hemoglobin/myoglobin (HHb). We also assessed the reliability and reproducibility of NIRS measurements of resting oxygen consumption and mitochondrial capacity. Twenty-four subjects, including four with chronic spinal cord injury, were tested using either the vastus lateralis or gastrocnemius muscles. Ten healthy, able-bodied subjects were tested on two occasions within a period of 7 days to assess the reliability and reproducibility. NIRS signals were corrected for blood volume changes using three different methods. Resting oxygen consumption had a mean coefficient of variation (CV) of 2.4% (range 1-32%). The recovery of oxygen consumption (mVo(2)) after electrical stimulation at 4 Hz was fit to an exponential curve, which represents mitochondrial capacity. The time constant for the recovery of mVo(2) was reproducible with a mean CV of 10% (range 1-22%) only when correcting for blood volume changes. We also examined the effects of adipose tissue thickness on measurements of mVo(2). We found the mVo(2) measurements using absolute units to be influenced by adipose tissue thickness (ATT), and this relationship was removed when an ischemic calibration was performed, supporting its use to compare mVo(2) between individuals of varying ATT. In conclusion, in vivo oxidative capacity can be assessed using blood volume-corrected NIRS signals with a high degree of reliability and reproducibility.

Juerg Feldmann

Fortiori Design LLC
Registered:
Posts: 1,530
 #4 
You can see   once somebody starts to play with it they get addicted:
 

A comparison of exercise type and intensity on the noninvasive assessment of skeletal muscle mitochondrial function using near-infrared spectroscopy.

Source

Department of Kinesiology, University of Georgia, Athens, Georgia 30602, USA. tryan7@me.com

Abstract

Near-infrared spectroscopy (NIRS) can be used to measure muscle oxygen consumption (mVO(2)) using arterial occlusions. The recovery rate of mVO(2) after exercise can provide an index of skeletal muscle mitochondrial function. The purpose of this study was to test the influence of exercise modality and intensity on NIRS measurements of mitochondrial function. Three experiments were performed. Thirty subjects (age: 18-27 yr) were tested. NIRS signals were corrected for blood volume changes. The recovery of mVO(2) after exercise was fit to a monoexponential curve, and a rate constant was calculated (directly related to mitochondrial function). No differences were found in NIRS rate constants for VOL and ES exercises (2.04 ± 0.57 vs. 2.01 ± 0.59 min(-1) for VOL and ES, respectively; P = 0.317). NIRS rate constants were independent of the contraction frequency for both VOL and ES (VOL: P = 0.166 and ES: P = 0.780). ES current intensity resulted in significant changes to the normalized time-tension integral (54 ± 11, 82 ± 7, and 100 ± 0% for low, medium, and high currents, respectively; P < 0.001) but did not influence NIRS rate constants (2.02 ± 0.54, 1.95 ± 0.44, 2.02 ± 0.46 min(-1) for low, medium, and high currents, respectively; P = 0.771). In summary, NIRS measurements of skeletal muscle mitochondrial function can be compared between VOL and ES exercises and were independent of the intensity of exercise. NIRS represents an important new technique that is practical for testing in research and clinical settings

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