An Approach to Noninvasive Fiber Type Determination by NMR

Boicelli, C. A.; Baldassarri, Angela M.; Borsetto, C; Conconi, F

doi:10.1055/s-2007-1024874

Cited by 17 publications

(11 citation statements)

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“…The pH was similar in both groups of athletes. The results principally confirm literature data (1,11,12).…”

Section: Discussionsupporting

confidence: 91%

“…BOICELLI et al (1) have found PCr/ATP ratios of 6.7-8.2 in the gastrocnemic muscle of sprint runners. These measurements were performed in 3 sprint runners with best times between 10.6-11.1 s. One of the athletes in that report must be classified as a middle-distance runner.…”

Section: Discussionmentioning

confidence: 98%

“…Experimental studies have revealed that muscle groups with a high ST fiber content have a lower creatinine phosphate (PCr) and inorganic phosphate (PCr/Pi) ratio than muscles of FT predominance (4,5). Only few data (1,2,10) are available on humans.…”

mentioning

confidence: 98%

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Muscle Metabolism of Professional Athletes using ³¹P-Spectroscopy

et al. 1999

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“…The pH was similar in both groups of athletes. The results principally confirm literature data (1,11,12).…”

Section: Discussionsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 98%

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Muscle Metabolism of Professional Athletes using ³¹P-Spectroscopy

et al. 1999

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“…Previously cross sectional NMR-studies have compared sprint and endurance trained runners and untrained subjects at rest [11], and it was demonstrated that long distance runners have faster CrP and P i kinetics in recovery after moderate intensity exercise compared to untrained controls [44]. During maximal effort total occlusions of the blood circulation to affected muscles occur, due to increased intra muscular pressure [36].…”

Section: Introductionmentioning

confidence: 98%

“…Several longitudinal studies [1,2,27,29,37,40] have shown that the two training types induce specific adaptations and cross sectional studies have demonstrated that marked qualitative differences may exist in fiber type distribution [16,21] and capillary supply [13,41] between differently trained groups.Previously cross sectional NMR-studies have compared sprint and endurance trained runners and untrained subjects at rest [11], and it was demonstrated that long distance runners have faster CrP and P i kinetics in recovery after moderate intensity exercise compared to untrained controls [44]. During maximal effort total occlusions of the blood circulation to affected muscles occur, due to increased intra muscular pressure [36].…”

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confidence: 98%

³¹P-MRS Characterization of Sprint and Endurance Trained Athletes

Johansen¹,

Quistorff²

2003

Int J Sports Med

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Muscle metabolism and force production were studied in sprint trained runners, endurance trained runners and in untrained subjects, using 31P-MRS. 31P-spectra were obtained at a time resolution of 5 s during four maximal isometric contractions of 30-sec duration, interspersed by 60-sec recovery intervals. Resting CrP/ATP ratio averaged 3.3 +/- 0.3, with no difference among the three groups. The sprint trained subjects showed about 20 % larger contraction forces in contraction bouts 1 and 2 (p < 0.05). The groups differed with respect to CrP breakdown (p < 0.05), with sprinters demonstrating about 75 % breakdown in each contraction compared to about 60 % and 40 % for untrained and endurance trained subjects, respectively (p < 0.05). The endurance trained runners showed almost twice as fast CrP recovery (t 1/2 = 12.5 +/- 1.5) compared to sprint trained (t 1/2 = 22.5 +/- 2.53) and untrained subjects (t 1/2 = 26.4 +/- 2.8). From the initial rate of CrP resynthesis the rate of maximal aerobic ATP synthesis was estimated to 0.74 +/- 0.07, 0.73 +/- 0.10 and 0.33 +/- 0.07 mmol ATP x kg -1 wet muscle x sec -1 for sprint trained, endurance trained and untrained subjects, respectively. Only the sprint trained and the untrained subjects displayed a significant drop in pH and only during the first of the four contractions, about 0.2 and 0.1 pH units, respectively, indicating that only under those contractions was the glycolytic proton production larger than the proton consumption by the CK reaction. Also, in the first contraction the energy cost of contraction was higher for the sprinters compared to the two other groups. The simple 31P-MRS protocol used in the present study demonstrates marked differences in force production, aerobic as well as anaerobic muscle metabolism, clearly allowing differentiation between endurance trained, sprint trained and untrained subjects.

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Relationships between Fiber Composition and NMR Measurements in Human Skeletal Muscle

et al. 1996

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The purpose of this study was to examine the relationships between the relative contents of phosphocreatine (PCr), inorganic phosphate (Pi), β‐adenosine triphosphate (ATP), and transverse relaxation time (T2) with fiber composition, which determined histochemically in the human skeletal muscle. The vastus lateralis muscles of 28 volunteers were subjected to phosphorus nuclear magnetic resonance (31P NMR) spectroscopy, magnetic resonance imaging (MRI) and muscle biopsy. Muscle fibers were divided into type I and type II fibers using myosin ATPase stain. A wide range of fiber composition levels were observed in the subjects (27.3–74.6% type I fibers). The PCr/ATP, Pi/ATP and (PCr+Pi)/ATP ratios were positively related to the percentage of type II fibers (r=0.695, p<0.001, r=0.429, p<0.05 and r=0.773, p<0.001, respectively). There was no correlation between fiber composition and the PCr/Pi ratio (r 0.127, n.s.) or intracellular pH (r=0.305, n.s.). Moreover, no correlation was found between T2 and fiber type (r=0.144, n.s.). These results suggest that 31P NMR can detect the differences in relative content of phosphates between type I and type II fibers, thereby noninvasively evaluating fiber composition in human skeletal muscle.

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An Approach to Noninvasive Fiber Type Determination by NMR

Cited by 17 publications

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Muscle Metabolism of Professional Athletes using ³¹P-Spectroscopy

Muscle Metabolism of Professional Athletes using ³¹P-Spectroscopy

³¹P-MRS Characterization of Sprint and Endurance Trained Athletes

Relationships between Fiber Composition and NMR Measurements in Human Skeletal Muscle

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An Approach to Noninvasive Fiber Type Determination by NMR

Cited by 17 publications

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Muscle Metabolism of Professional Athletes using 31P-Spectroscopy

Muscle Metabolism of Professional Athletes using 31P-Spectroscopy

31P-MRS Characterization of Sprint and Endurance Trained Athletes

Relationships between Fiber Composition and NMR Measurements in Human Skeletal Muscle

Contact Info

Product

Resources

About

Muscle Metabolism of Professional Athletes using ³¹P-Spectroscopy

Muscle Metabolism of Professional Athletes using ³¹P-Spectroscopy

³¹P-MRS Characterization of Sprint and Endurance Trained Athletes