Eccentric muscle damage increases intermuscular coherence during a fatiguing isometric contraction

2013 ◽  
Vol 208 (4) ◽  
pp. 362-375 ◽  
Author(s):  
J. G. Semmler ◽  
S. A. Ebert ◽  
J. Amarasena
Keyword(s):  
Muscle Damage ◽  
Isometric Contraction ◽  
Intermuscular Coherence ◽  
Eccentric Muscle Damage

Dietary Cholesterol Alters Recovery from Eccentric Muscle Damage in Humans

2006 ◽  
Vol 38 (Supplement) ◽  
pp. S386
Author(s):  
Steven Riechman ◽  
David Kean ◽  
Ryan D. Andrews ◽  
Heath Gasier ◽  
Steven Hammer
Keyword(s):  
Muscle Damage ◽  
Dietary Cholesterol ◽  
Eccentric Muscle Damage

CHANGES IN THE T-TUBULAR SYSTEM FOLLOWING ECCENTRIC MUSCLE DAMAGE

2002 ◽  
Vol 34 (5) ◽  
pp. S204
Author(s):  
E W. Yeung ◽  
C D. Balnave ◽  
H J. Ballard ◽  
J -P Bourreau ◽  
D G. Allen
Keyword(s):  
Muscle Damage ◽  
Tubular System ◽  
Eccentric Muscle Damage

Reduced short-interval intracortical inhibition after eccentric muscle damage in human elbow flexor muscles

2012 ◽  
Vol 113 (6) ◽  
pp. 929-936 ◽  
Author(s):  
Bradley M. Pitman ◽  
John G. Semmler
Keyword(s):  
Muscle Damage ◽  
Eccentric Exercise ◽  
Muscle Soreness ◽  
Joint Angle ◽  
Short Interval ◽  
Intracortical Inhibition ◽  
Elbow Flexor ◽  
Flexor Muscles ◽  
Elbow Flexor Muscles ◽  
Eccentric Muscle Damage

The purpose of this study was to use paired-pulse transcranial magnetic stimulation (TMS) to examine the effect of eccentric exercise on short-interval intracortical inhibition (SICI) after damage to elbow flexor muscles. Nine young (22.5 ± 0.6 yr; mean ± SD) male subjects performed maximal eccentric exercise of the elbow flexor muscles until maximal voluntary contraction (MVC) force was reduced by ∼40%. TMS was performed before, 2 h after, and 2 days after exercise under Rest and Active (5% MVC) conditions with motor-evoked potentials (MEPs) recorded from the biceps brachii (BB) muscle. Peripheral electrical stimulation of the brachial plexus was used to assess maximal M-waves, and paired-pulse TMS with a 3-ms interstimulus interval was used to assess changes in SICI at each time point. The eccentric exercise resulted in a 34% decline in strength ( P < 0.001), a 41% decline in resting M-wave ( P = 0.01), changes in resting elbow joint angle (10°, P < 0.001), and a shift in the optimal elbow joint angle for force production (18°, P < 0.05) 2 h after exercise. This was accompanied by impaired muscle strength (27%, P < 0.001) and increased muscle soreness ( P < 0.001) 2 days after exercise, which is indicative of muscle damage. When the test MEP amplitudes were matched between sessions, we found that SICI was reduced by 27% in resting and 23% in active BB muscle 2 h after exercise. SICI recovered 2 days after exercise when muscle pain and soreness were present, suggesting that delayed onset muscle soreness from eccentric exercise does not influence SICI. The change in SICI observed 2 h after exercise suggests that eccentric muscle damage has widespread effects throughout the motor system that likely includes changes in motor cortex.

Short-Term β-Hydroxy-β-Methylbutyrate Supplementation Does Not Reduce Symptoms of Eccentric Muscle Damage

2001 ◽  
Vol 11 (4) ◽  
pp. 442-450 ◽  
Author(s):  
Douglas Paddon-Jones ◽  
Andrew Keech ◽  
David Jenkins
Keyword(s):  
Body Weight ◽  
Muscle Damage ◽  
Eccentric Exercise ◽  
Muscle Soreness ◽  
Exercise Bout ◽  
Similar Amount ◽  
Short Term ◽  
Placebo Condition ◽  
Post Exercise ◽  
Eccentric Muscle Damage

Purpose:We examined the effects of short-term β-hydroxy-β-methylbutyrate (HMB) supplementation on symptoms of muscle damage following an acute bout of eccentric exercise.Methods:Non-resistance trained subjects were randomly assigned to a HMB supplement group (HMB, 40mg/kg body weight/day, n = 8) or placebo group (CON, n = 9). Supplementation commenced 6 days prior to a bout of 24 maximal isokinetic eccentric contractions of the elbow flexors and continued throughout post-testing. Muscle soreness, upper arm girth, and torque measures were assessed pre-exercise, 15 min post-exercise, and 1,2,3, 4,7, and 10 days post-exercise.Results:No pre-test differences between HMB and CON groups were identified, and both performed a similar amount of eccentric work during the main eccentric exercise bout (p > .05). HMB supplementation had no effect on swelling, muscle soreness, or torque following the damaging eccentric exercise bout (p > .05).Conclusion:Compared to a placebo condition, short-term supplementation with 40mg/kg body weight/day of HMB had no beneficial effect on a range of symptoms associated with eccentric muscle damage. If HMB can produce an ergogenic response, a longer pre-exercise supplementation period may be necessary.

scholarly journals Blood Flow After Exercise-Induced Muscle Damage

2015 ◽  
Vol 50 (4) ◽  
pp. 400-406 ◽  
Author(s):  
Noelle M. Selkow ◽  
Daniel C. Herman ◽  
Zhenqi Liu ◽  
Jay Hertel ◽  
Joseph M. Hart ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Muscle Damage ◽  
Blood Volume ◽  
Visual Analog Scale ◽  
Blood Flow Velocity ◽  
Acute Inflammation ◽  
Analog Scale ◽  
Muscle Perfusion ◽  
Eccentric Muscle Damage

Context The most common modality used to address acute inflammation is cryotherapy. Whereas pain decreases with cryotherapy, evidence that changes occur in perfusion of skeletal muscle is limited. We do not know whether ice attenuates the increases in perfusion associated with acute inflammation. Objective To examine the effects of repeated applications of ice bags on perfusion of the gastrocnemius muscle after an eccentric exercise protocol. Design Controlled laboratory study. Setting Laboratory. Patients or Other Participants Eighteen healthy participants (3 men, 15 women; age = 22.2 ± 2.2 years, height = 166.0 ± 11.9 cm, mass = 69.4 ± 25.0 kg). Intervention(s) To induce eccentric muscle damage, participants performed 100 unilateral heel-lowering exercises off a step to the beat of a metronome. A randomized intervention (cryotherapy, sham, control) was applied to the exercised lower extremity immediately after the protocol and again at 10, 24, and 34 hours after the protocol. Main Outcome Measure(s) Baseline perfusion measurements (blood volume, blood flow, and blood flow velocity) were taken using contrast-enhanced ultrasound of the exercised leg. Perfusion was reassessed after the first intervention and 48 hours after the protocol as percentage change scores. Pain was measured with a visual analog scale at baseline and at 10, 24, 34, and 48 hours after the protocol. Separate repeated-measures analyses of variance were used to assess each dependent variable. Results We found no interactions among interventions for microvascular perfusion. Blood volume and blood flow, however, increased in all conditions at 48 hours after exercise (P &lt; .001), and blood flow velocity decreased postintervention from baseline (P = .041). We found a time-by-intervention interaction for pain (P = .009). Visual analog scale scores were lower for the cryotherapy group than for the control group at 34 and 48 hours after exercise. Conclusions Whereas eccentric muscle damage resulted in increased blood flow, ice did not decrease muscle perfusion 48 hours after exercise. Therefore, ice does not seem to decrease muscle perfusion when blood flow is elevated, as it would be during inflammation.

scholarly journals Neuromuscular And Perceptual Aspects Of Eccentric Muscle Damage And Recovery

2009 ◽  
Vol 41 ◽  
pp. 198
Author(s):  
Steven J. Elmer ◽  
Kimberly E. Hall ◽  
Stephanie R. Peters ◽  
James C. Martin
Keyword(s):  
Muscle Damage ◽  
Eccentric Muscle Damage
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