Serum Creatine Kinase Increases after Acute Strength Training in College Athletes with Menstrual Irregularities

Chronic menstrual dysfunction and low female sex hormones adversely affect muscular performance in women but studies in college athletes are scarce. A cohort of 18 Japanese, female college athletes at the University of Tsukuba, Japan, were recruited and studied over 3 weeks under 2 conditions. One group had normal menstrual cycling (CYC, 9 athletes) while the other had irregular cycles (DYS, 9 athletes). Hormones and creatine kinase (CK) were measured from blood under both rest (RE) and exercise (EX) conditions. Biceps femoris tendon stiffness was measured by myometry. No differences in age, height, weight, menarche age, or one-repetition maximum weight existed between the groups. The DYS group had persistently low levels of estrogen and progesterone. In the CYC group, the CK level significantly increased at each point immediately post-exercise and 24 h post-exercise compared to pre-exercise in Weeks 1 and 2, and significantly increased at 24 h post-exercise compared to pre-exercise status in Week 3. The DYS group was significantly different only between pre-exercise and 24 h post-exercise over all 3 weeks. The DYS group also suffered from higher biceps femoris tendon stiffness at 24 h post-exercise. Chronic menstrual irregularities in Japanese college athletes increase muscle damage markers in the bloodstream and muscle stiffness after acute strength training.

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Moderate-duration static stretch reduces active and passive plantar flexor moment but not Achilles tendon stiffness or active muscle length

Journal of Applied Physiology ◽

10.1152/japplphysiol.91476.2008 ◽

2009 ◽

Vol 106 (4) ◽

pp. 1249-1256 ◽

Cited By ~ 91

Author(s):

Anthony D. Kay ◽

Anthony J. Blazevich

Keyword(s):

Mechanical Properties ◽

Achilles Tendon ◽

Muscle Stiffness ◽

Triceps Surae ◽

Medial Gastrocnemius ◽

Static Stretch ◽

Tendon Stiffness ◽

Neuromuscular Activity ◽

Time Motion ◽

The Impact

The effects of static stretch on muscle and tendon mechanical properties and muscle activation were studied in fifteen healthy human volunteers. Peak active and passive moment data were recorded during plantar flexion trials on an isokinetic dynamometer. Electromyography (EMG) monitoring of the triceps surae muscles, real-time motion analysis of the lower leg, and ultrasound imaging of the Achilles-medial gastrocnemius muscle-tendon junction were simultaneously conducted. Subjects performed three 60-s static stretches before being retested 2 min and 30 min poststretch. There were three main findings in the present study. First, peak concentric moment was significantly reduced after stretch; 60% of the deficit recovered 30 min poststretch. This was accompanied by, and correlated with ( r = 0.81 ; P < 0.01) reductions in peak triceps surae EMG amplitude, which was fully recovered at 30 min poststretch. Second, Achilles tendon length was significantly shorter during the concentric contraction after stretch and at 30 min poststretch; however, no change in tendon stiffness was detected. Third, passive joint moment was significantly reduced after stretch, and this was accompanied by significant reductions in medial gastrocnemius passive muscle stiffness; both measures fully recovered by 30 min poststretch. These data indicate that the stretching protocol used in this study induced losses in concentric moment that were accompanied by, and related to, reductions in neuromuscular activity, but they were not associated with alterations in tendon stiffness or shorter muscle operating length. Reductions in passive moment were associated with reductions in muscle stiffness, whereas tendon mechanics were unaffected by the stretch. Importantly, the impact on mechanical properties and neuromuscular activity was minimal at 30 min poststretch.

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High-Volume Light-Load Strength Training, but Not Low-Volume Heavy-Load Strength Training Increases Corticospinal Excitability

The Journal of Science and Medicine ◽

10.37714/josam.v2i3.47 ◽

2020 ◽

Vol 2 (3) ◽

pp. 1-12

Author(s):

Rhys Painter ◽

Simin Rahman ◽

Woo Kim ◽

Ummatul Siddique ◽

Ashlyn Frazer ◽

...

Keyword(s):

Strength Training ◽

Short Interval ◽

High Volume ◽

Intracortical Inhibition ◽

Corticospinal Excitability ◽

Control Group ◽

Heavy Load ◽

Post Exercise ◽

Light Load ◽

Low Volume

Purpose: To determine whether corticospinal excitability (CSE) and inhibition are differentially modulated following high-volume light-load strength training compared to low-volume heavy-load strength training. We hypothesised high-volume light-load strength training would increase CSE and low-volume heavy-load strength training would reduce intracortical inhibition. Methods: Transcranial magnetic stimulation (TMS) was used to assess CSE, short-interval intracortical inhibition (SICI), and silent period duration (SP) following high-volume light-load strength training (n = 9), low-volume heavy-load strength training (n = 8) compared to a control group (n = 10). Twenty-seven participants completed either (1) low-volume heavy-load strength training (80% one-repetition maximum [1RM]); (2) high-volume light-load strength training (20% 1-RM) or (3) a control condition. CSE, SICI and SP were measured using TMS at baseline and four time-points over a 60 min post-exercise period. Results: CSE increased rapidly (within 5 min post-exercise) for high-volume light-load strength training and remained elevated for 60 min compared to low-volume heavy-load strength training and control groups. There were no differences following any training for reduced SICI or SP. Conclusion: These results suggest that high-volume light-load strength training increases the excitability of corticospinal neurons and this increase is likely to be the predominant mechanism for increasing CSE for up to 60 min post training. It may be possible that a greater number of ST sessions are required to observe any differences in the excitability of the intrinsic inhibitory motor-network following high-volume light-load strength training and low-volume heavy-load strength training.

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Ultrafast Ultrasound-Derived Muscle Strain Measure Correlates with Carotid Local Pulse Wave Velocity in Habitual Resistance-Trained Individuals

Applied Sciences ◽

10.3390/app11188783 ◽

2021 ◽

Vol 11 (18) ◽

pp. 8783

Author(s):

Hsin-Fu Lin ◽

Yi-Hung Liao ◽

Pai-Chi Li

Keyword(s):

Pulse Wave Velocity ◽

Resistance Exercise ◽

Strain Rate ◽

Wave Velocity ◽

Exercise Intensity ◽

Pulse Wave ◽

Muscle Stiffness ◽

Ultrasound Elastography ◽

Muscle Strain ◽

Post Exercise

Purpose: this study investigated the effects of the intensity of machine-based bicep curl resistance exercise on ultrafast ultrasound-derived muscle strain rate and carotid ultrafast pulse wave velocity (ufPWV), and examined the association between muscle strain rate, ufPWV, and established carotid function measures in habitual resistance-trained individuals. Methods: twenty-three young habitual resistance-trained males (age: 24 ± 1 year, body mass index = 24 ± 1 kg/m2) were recruited to participate in two bouts of acute bicep curl exercise. After one-repetition maximum determination (1RM), the participants were randomly assigned to engage in bicep curls at 40 or 80%1RM intensity (10 reps × five sets) by a crossover study design. The muscle strain rate of bicep muscle, carotid ufPWV during systole(ufPWV-sys), and diastole (ufPWV-dia) were obtained pre- and post-exercise. In addition, carotid function measures were calculated by obtained carotid diameter and central blood pressure changes. Results: compared with pre-exercise, the reduction in post-exercise muscle strain rate and its area under the curve of 80%1RM was greater than those of 40%1RM. Both ufPWV-sys and ufPWV-dia increased regardless of exercise intensity. Baseline bicep muscle strain rate correlated not only with ufPWV-sys (r = −0.71, p = 0.001), ufPWV-dia (r = −0.74, p = 0.001), but also carotid compliance (r = 0.49, p = 0.02), distensibility (r = 0.54, p = 0.01) and ß stiffness (r= −0.84, p < 0.0001). The ufPWVs also correlated with ß stiffness (r = 0.64–0.76, p = 0.01). Conclusion: muscle stiffness measured by ultrafast ultrasound elastography increases positively with resistance exercise intensity, and it appears to correlate with carotid ufPWV and established carotid function measures in habitual resistance-trained individuals.

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Surgical management of tendinopathy of biceps femoris tendon in athletes

Disability and Rehabilitation ◽

10.1080/09638280701786120 ◽

2008 ◽

Vol 30 (20-22) ◽

pp. 1602-1607 ◽

Cited By ~ 21

Author(s):

Umile Giuseppe Longo ◽

Giorgio Garau ◽

Vincenzo Denaro ◽

Nicola Maffulli

Keyword(s):

Surgical Management ◽

Biceps Femoris ◽

Biceps Femoris Tendon

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Evaluation of the Acupuncture Needling Effect on Post-Exercise Muscle Stiffness by Newly Devised Muscle Hardness Meter

The Showa University Journal of Medical Sciences ◽

10.15369/sujms1989.4.135 ◽

1992 ◽

Vol 4 (2) ◽

pp. 135-140 ◽

Cited By ~ 2

Author(s):

Takao SATO ◽

Tadashi HISAMITSU ◽

Michio SATO ◽

Chifuyu TAKESHIGE

Keyword(s):

Muscle Stiffness ◽

Post Exercise ◽

Muscle Hardness ◽

Exercise Muscle

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Subluxating Biceps Femoris Tendon: An Unusual Case of Lateral Knee Pain in a Soccer Athlete

The American Journal of Sports Medicine ◽

10.1177/03635465010290012101 ◽

2001 ◽

Vol 29 (1) ◽

pp. 93-95 ◽

Cited By ~ 27

Author(s):

Bernard R. Bach ◽

Keith Minihane

Keyword(s):

Knee Pain ◽

Unusual Case ◽

Biceps Femoris ◽

Lateral Knee Pain ◽

Biceps Femoris Tendon

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Increased fascicle length but not patellar tendon stiffness after accentuated eccentric-load strength training in already-trained men

European Journal of Applied Physiology ◽

10.1007/s00421-020-04462-x ◽

2020 ◽

Vol 120 (11) ◽

pp. 2371-2382 ◽

Cited By ~ 1

Author(s):

Simon Walker ◽

Joanne Trezise ◽

Guy Gregory Haff ◽

Robert U. Newton ◽

Keijo Häkkinen ◽

...

Keyword(s):

Strength Training ◽

Patellar Tendon ◽

External Load ◽

Vastus Lateralis ◽

Knee Extensor ◽

Fascicle Length ◽

Tendon Stiffness ◽

Knee Extensor Strength ◽

Tendon Properties ◽

Fascicle Angle

Abstract Purpose This study examined whether additional external load during the eccentric phase of lower limb strength training exercises led to greater adaptations in knee extensor strength, muscle architecture, and patellar tendon properties than traditional concentric–eccentric training in already-trained men. Methods Twenty-eight men accustomed to strength training were randomized to undertake 10 weeks of supervised traditional (TRAD) or accentuated eccentric loading (AEL) or continue their habitual unsupervised (CON) strength training. TRAD and AEL trained 2∙week−1 with a six-repetition maximum (RM) session and a ten-RM session. TRAD used the same external load in both concentric and eccentric phases, while AEL used 40% greater load during the eccentric than concentric phase. Tests were performed at pre- and post-training, including: maximum unilateral isokinetic (30°·s−1) concentric, eccentric and isometric torques by isokinetic dynamometry, unilateral isometric ramp contractions with muscle–tendon ultrasound imaging to measure tendon stiffness and hysteresis, and resting vastus lateralis and medialis fascicle angle and length measured by extended-field-of-view ultrasound. Results After training, both TRAD and AEL significantly increased maximum concentric and isometric torque (p < 0.05), but only AEL increased eccentric torque (AEL: + 10 ± 9%, TRAD: + 4 ± 9%) and vastus lateralis (AEL: + 14 ± 14%, TRAD: + 1 ± 10%) and medialis (AEL: + 19 ± 8%, TRAD: + 5 ± 11%) fascicle length. Conclusion Both TRAD and AEL increased maximum knee extensor strength but only AEL increased VL and VM fascicle length. Neither training program promoted changes in fascicle angle or changes in patellar tendon properties in our already-trained men.

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