Muscle function during repetitive moderate-intensity muscle contractions in myoadenylate deaminase-deficient Dutch subjects

2002 ◽  
Vol 102 (5) ◽  
pp. 531-539 ◽  
Author(s):  
C.J. DE RUITER ◽  
A.M. MAY ◽  
B.G.M. VAN ENGELEN ◽  
R.A. WEVERS ◽  
G.C. STEENBERGEN-SPANJERS ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Exercise Test ◽  
Muscle Contractions ◽  
Moderate Intensity ◽  
Control Subjects ◽  
Generating Capacity ◽  
Myoadenylate Deaminase ◽  
Baseline Values ◽  
Isometric Muscle ◽  
Femoris Muscle

We investigated whether the capacity for repetitive submaximal muscle contraction was reduced in a group of subjects (n = 8) with a primary deficiency of myoadenylate deaminase (MAD). Quadriceps femoris muscle fatigue was evaluated using voluntary and electrically stimulated contractions during 20min of repetitive voluntary isometric contractions at 40% of maximal force-generating capacity (MFGC). After 5min of exercise, MFGC had declined significantly to 70.6±4.1% (mean±S.E.M.) and 87.2±1.6% of baseline values in MAD-deficient and sedentary control subjects (n = 8) respectively (P = 0.002 between groups). After 5min of exercise, the half-relaxation time had increased significantly to 113.4±6.1% of basline in MAD-deficient muscle, but had decreased significantly to 94.1±1.3% in control subjects (P = 0.003 between groups). All control subjects completed the 20-min exercise test. Five of the MAD-deficient subjects had to stop exercising due to early muscle fatigue; however, three of the MAD-deficient subjects were able to complete the 20-min exercise test. In conclusion, although the capacity for repetitive submaximal isometric muscle contractions for the group of MAD-deficient subjects was significantly decreased, it remains uncertain whether MAD deficiency is the sole cause of pronounced muscle fatigue.

Ischaemic exercise test in myoadenylate deaminase deficiency and McArdle's disease: measurement of plasma adenosine, inosine and hypoxanthine

1986 ◽  
Vol 70 (4) ◽  
pp. 399-401 ◽  
Author(s):  
S. P. T. Sinkeler ◽  
E. M. G. Joosten ◽  
R. A. Wevers ◽  
R. A. Binkhorst ◽  
F. T. Oerlemans ◽  
...  
Keyword(s):  
Exercise Test ◽  
Diagnostic Value ◽  
Myoadenylate Deaminase Deficiency ◽  
Control Subjects ◽  
Mcardle's Disease ◽  
Before And After ◽  
Myoadenylate Deaminase ◽  
Mcardle’S Disease ◽  
Forearm Exercise ◽  
Plasma Adenosine

1. Plasma adenosine, inosine and hypoxanthine concentrations were assayed in seven control subjects, five myoadenylate deaminase deficient (MADD) patients and six McArdle patients before and after ischaemic forearm exercise. 2. The plasma adenosine increase was very low in all test groups and there were no significant differences. 3. The MADD patients showed a significantly lower increase of plasma inosine and hypoxanthine after exercise as compared with the controls. 4. In the McArdle patients the increase in plasma inosine and hypoxanthine after exercise did not differ significantly from the values measured in the controls. 5. The ischaemic exercise test with measurement of plasma inosine and hypoxanthine might be of diagnostic value in MADD, but not in McArdle's disease.

Muscle function during repetitive moderate-intensity muscle contractions in myoadenylate deaminase-deficient Dutch subjects

2002 ◽  
Vol 102 (5) ◽  
pp. 531 ◽  
Author(s):  
C. J. de RUITER ◽  
A. M. MAY ◽  
B. G. M. van ENGELEN ◽  
R. A. WEVERS ◽  
G. C. STEENBERGEN-SPANJERS ◽  
...  
Keyword(s):  
Muscle Function ◽  
Muscle Contractions ◽  
Moderate Intensity ◽  
Myoadenylate Deaminase

Unilateral isometric muscle fatigue decreases force production and activation of contralateral knee extensors but not elbow flexors

2014 ◽  
Vol 39 (12) ◽  
pp. 1338-1344 ◽  
Author(s):  
Israel Halperin ◽  
David Copithorne ◽  
David G. Behm
Keyword(s):  
Muscle Fatigue ◽  
Force Production ◽  
Voluntary Activation ◽  
Knee Extensors ◽  
Elbow Flexors ◽  
Post Intervention ◽  
Nonlocal Effects ◽  
And Performance ◽  
Voluntary Contractions ◽  
Isometric Muscle

Nonlocal muscle fatigue occurs when fatiguing 1 muscle alters performance of another rested muscle. The purpose of the study was to investigate if fatiguing 2 separate muscles would affect the same rested muscle, and if fatiguing the same muscle would affect 2 separate muscles. Twenty-one trained males participated in 2 studies (n = 11; n = 10). Subjects performed 2 pre-test maximum voluntary contractions (MVCs) with the nondominant knee extensors. Thereafter they performed two 100-s MVCs with their dominant knee extensors, elbow flexors, or rested. Between and after the sets, a single MVC with the nondominant rested knee extensors was performed. Subsequently, 12 nondominant knee extensors repeated MVCs were completed. Force, quadriceps voluntary activation (VA), and electromyography (EMG) were measured. The same protocol was employed in study 2 except the nondominant elbow-flexors were tested. Study 1: Compared with control conditions, a significant decrease in nondominant knee extensors force, EMG, and VA was found under both fatiguing conditions (P ≤ 0.05; effect size (ES) = 0.91–1.15; 2%–8%). Additionally, decrements in all variables were found from the first post-intervention MVC to the last (P ≤ 0.05; ES = 0.82–2.40; 9%–20%). Study 2: No differences were found between conditions for all variables (P ≥ 0.33; ES ≤ 0.2; ≤3.0%). However, all variables decreased from the first post-intervention MVC to the last (P ≤ 0.05; ES = 0.4–3.0; 7.2%–19.7%). Whereas the rested knee extensors demonstrated nonlocal effects regardless of the muscle being fatigued, the elbow-flexors remained unaffected. This suggests that nonlocal effects are muscle specific, which may hold functional implications for training and performance.

Shortening of muscle relaxation time after creatine loading

1999 ◽  
Vol 86 (3) ◽  
pp. 840-844 ◽  
Author(s):  
M. van Leemputte ◽  
K. Vandenberghe ◽  
P. Hespel
Keyword(s):  
Relaxation Time ◽  
Muscle Relaxation ◽  
Muscle Contractions ◽  
Contraction Time ◽  
Healthy Male ◽  
Healthy Male Volunteers ◽  
Torque Generation ◽  
Isometric Torque ◽  
The Mean ◽  
Isometric Muscle

The effect of creatine (Cr) supplementation on muscle isometric torque generation and relaxation was investigated in healthy male volunteers. Maximal torque (Tmax), contraction time (CT) from 0.25 to 0.75 of Tmax, and relaxation time (RT) from 0.75 to 0.25 of Tmax were measured during 12 maximal isometric 3-s elbow flexions interspersed by 10-s rest intervals. Between the pretest and the posttest, subjects ingested Cr monohydrate (4 × 5 g/day; n = 8) or placebo ( n = 8) for 5 days. Pretest Tmax, CT, and RT were similar in Cr and placebo groups. Also in the posttest, Tmax and CT were similar between groups. However, posttest RT was decreased consistently by ∼20% ( P < 0.05) in the Cr group from the first to the last of the 12 contractions. In addition, the mean decrease in RT after Cr loading was positively correlated with pretest RT ( r = 0.82). It is concluded that Cr loading facilitates the rate of muscle relaxation during brief isometric muscle contractions without affecting torque production.

scholarly journals Dynamic optimization of stimulation frequency to reduce isometric muscle fatigue using a modified Hill‐Huxley model

2017 ◽  
Vol 57 (4) ◽  
pp. 634-641 ◽  
Author(s):  
Brian D. Doll ◽  
Nicholas A. Kirsch ◽  
Xuefeng Bao ◽  
Brad E. Dicianno ◽  
Nitin Sharma
Keyword(s):  
Muscle Fatigue ◽  
Dynamic Optimization ◽  
Stimulation Frequency ◽  
Isometric Muscle

Muscle fatigue and exhaustion during dynamic leg exercise in normoxia and hypobaric hypoxia

1996 ◽  
Vol 81 (5) ◽  
pp. 1891-1900 ◽  
Author(s):  
Charles S. Fulco ◽  
Steven F. Lewis ◽  
Peter N. Frykman ◽  
Robert Boushel ◽  
Sinclair Smith ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Hypobaric Hypoxia ◽  
Knee Extension ◽  
Work Rate ◽  
Dynamic Exercise ◽  
Time To Exhaustion ◽  
Electromyographic Activity ◽  
Constant Work Rate ◽  
Generating Capacity ◽  
Leg Exercise

Fulco, Charles S., Steven F. Lewis, Peter N. Frykman, Robert Boushel, Sinclair Smith, Everett A. Harman, Allen Cymerman, and Kent B. Pandolf. Muscle fatigue and exhaustion during dynamic leg exercise in normoxia and hypobaric hypoxia. J. Appl. Physiol. 81(5): 1891–1900, 1996.—Using an exercise device that integrates maximal voluntary static contraction (MVC) of knee extensor muscles with dynamic knee extension, we compared progressive muscle fatigue, i.e., rate of decline in force-generating capacity, in normoxia (758 Torr) and hypobaric hypoxia (464 Torr). Eight healthy men performed exhaustive constant work rate knee extension (21 ± 3 W, 79 ± 2 and 87 ± 2% of 1-leg knee extension O2 peak uptake for normoxia and hypobaria, respectively) from knee angles of 90–150° at a rate of 1 Hz. MVC (90° knee angle) was performed before dynamic exercise and during ≤5-s pauses every 2 min of dynamic exercise. MVC force was 578 ± 29 N in normoxia and 569 ± 29 N in hypobaria before exercise and fell, at exhaustion, to similar levels (265 ± 10 and 284 ± 20 N for normoxia and hypobaria, respectively; P > 0.05) that were higher ( P < 0.01) than peak force of constant work rate knee extension (98 ± 10 N, 18 ± 3% of MVC). Time to exhaustion was 56% shorter for hypobaria than for normoxia (19 ± 5 vs. 43 ± 7 min, respectively; P < 0.01), and rate of right leg MVC fall was nearly twofold greater for hypobaria than for normoxia (mean slope = −22.3 vs. −11.9 N/min, respectively; P < 0.05). With increasing duration of dynamic exercise for normoxia and hypobaria, integrated electromyographic activity during MVC fell progressively with MVC force, implying attenuated maximal muscle excitation. Exhaustion, per se, was postulated to relate more closely to impaired shortening velocity than to failure of force-generating capacity.

Preparation and Functionality Research of Anion Functional Fabrics

2010 ◽  
Vol 178 ◽  
pp. 216-219
Author(s):  
Qing Shan Li ◽  
Ming Shuang Xu
Keyword(s):  
Muscle Fatigue ◽  
Application Research ◽  
Significant Difference ◽  
Generating Capacity ◽  
Exercise Induced

In order to provide scientific proof to anion functional fabrics application research in textile domain, in this article, anion functional fabrics were prepared, the anion generating capacity was determined and the effect of anion fabrics and mice BLA after exercise were first studied. The anion generating capacity shows that: due to the adding of anion function powders to function fabrics, the anion amount released by function fabrics is apparently higher than common fabrics. Washing can not significantly reduce the anion amount of function fabrics releasing. These can indicate that the function fabrics can release anion stable and lasting. The determination of mice’s BLA after swimming showed that Compared to common fabrics, functional fabrics have significant difference (P<0.05). The anions of functional fabrics releasing can reduce animals BLA after exercise and help to eliminate exercise-induced muscle fatigue.

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