Lack of variation in muscle strength with menstrual status in healthy women aged 45–54 years: data from a national survey

OBJECTIVE: Bone mineral density (BMD) is under strong genetic control and a number of candidate genes have been associated with BMD. Both muscle strength and body weight are considered to be important predictors of BMD but far less is known about the genes affecting muscle strength and fat mass. The purpose of this study was to investigate the poly adenosine (A) repeat and the BsmI SNP in the vitamin D receptor (VDR) in relation to muscle strength and body composition in healthy women. DESIGN: A population-based study of 175 healthy women aged 20-39 years was used. METHODS: The polymorphic regions in the VDR gene (the poly A repeat and the BsmI SNP) were amplified by PCR. Body mass measurements (fat mass, lean mass, body weight and body mass index) and muscle strength (quadriceps, hamstring and grip strength) were evaluated. RESULTS: Individuals with shorter poly A repeat, ss and/or absence of the linked BsmI restriction site (BB) have higher hamstring strength (ss vs LL, P=0.02), body weight (ss vs LL, P=0.049) and fat mass (ss vs LL, P=0.04) compared with women with a longer poly A repeat (LL) and/or the presence of the linked BsmI restriction site (bb). CONCLUSIONS: Genetic variation in the VDR is correlated with muscle strength, fat mass and body weight in premenopausal women. Further functional studies on the poly A microsatellite are needed to elucidate whether this is the functionally relevant locus or if the polymorphism is in linkage disequilibrium with a functional variant in a closely situated gene further downstream of the VDR 3'UTR.

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Effects of functional resistance training on muscle strength and musculoskeletal discomfort

Fisioterapia em Movimento ◽

10.1590/1980-5918.030.002.ao15 ◽

2017 ◽

Vol 30 (2) ◽

pp. 347-356 ◽

Cited By ~ 1

Author(s):

Bruna Montechieze Cassemiro ◽

Ítalo Ribeiro Lemes ◽

Maria Paula Ferreira de Figueiredo ◽

Franciele Marques Vanderlei ◽

Carlos Marcelo Pastre ◽

...

Keyword(s):

Statistical Analysis ◽

Resistance Training ◽

Muscle Strength ◽

Physical Fitness ◽

Musculoskeletal Complaints ◽

Musculoskeletal Discomfort ◽

Training Groups ◽

Healthy Women ◽

Nordic Musculoskeletal Questionnaire ◽

Level Of Significance

Abstract Introduction: Functional resistance training (FRT) is becoming increasingly popular to improve physical fitness of practitioners, however, yet there are gaps in knowledge about effectiveness of FRT in relation conventional resistance training (CRT) in several ambits, as musculoskeletal complaints. Objective: Compare the effect of FRT and CRT in the musculoskeletal discomfort and magnitude of gain in muscle strength in healthy women. Methods: 52 women was divided into three groups, FRT (n = 15; 22 ± 2.35 years): functional resistance training; CRT (n = 14; 22.5 ± 1.78 years): conventional resistance training and CG (n = 13; 20.6 ± 1.10 years): no type of intervention. The training was periodized in 30 sessions over 12 weeks with 3 sessions per week. For the muscle strength variable used the 1RM test and for the musculoskeletal discomfort variable, the Nordic Musculoskeletal Questionnaire (NMQ). Regarding the statistical analysis, all results took into consideration a 5% level of significance. Results: Considerable gain in muscle strength was observed for all exercises in both training groups. In addition, there was a tendency in CRT to relate a more musculoskeletal discomfort; presented 27.3% more complaints compared FRT in the MNQ. Conclusion: The FRT was as effective as the CRT for improving muscle strength, furthermore, there was a tendency for FRT to cause less musculoskeletal discomfort.

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Relationship Between Gluteal Muscle Strength, Corticospinal Excitability, and Jump-Landing Biomechanics in Healthy Women

Journal of Sport Rehabilitation ◽

10.1123/jsr.22.4.239 ◽

2013 ◽

Vol 22 (4) ◽

pp. 239-247 ◽

Cited By ~ 9

Author(s):

Adam S. Lepley ◽

Allison M. Strouse ◽

Hayley M. Ericksen ◽

Kate R. Pfile ◽

Phillip A. Gribble ◽

...

Keyword(s):

Muscle Strength ◽

Outcome Measures ◽

Motor Evoked Potentials ◽

Gluteus Maximus ◽

Gluteus Medius ◽

Corticospinal Excitability ◽

Gluteal Muscle ◽

Jump Landing ◽

Healthy Women ◽

Landing Biomechanics

Context:Components of gluteal neuromuscular function, such as strength and corticospinal excitability, could potentially influence alterations in lower extremity biomechanics during jump landing.Objective:To determine the relationship between gluteal muscle strength, gluteal corticospinal excitability, and jump-landing biomechanics in healthy women.Setting:University laboratory.Design:Descriptive laboratory study.Participants:37 healthy women (21.08 ± 2.15 y, 164.8 ± 5.9 cm, 65.4 ± 12.0 kg).Interventions:Bilateral gluteal strength was assessed through maximal voluntary isometric contractions (MVIC) using an isokinetic dynamometer. Strength was tested in the open chain in prone and side-lying positions for the gluteus maximus and gluteus medius muscles, respectively. Transcranial magnetic stimulation was used to elicit measures of corticospinal excitability. Participants then performed 3 trials of jump landing from a 30-cm box to a distance of 50% of their height, with an immediate rebound to a maximal vertical jump. Each jump-landing trial was video recorded (2-D) and later scored for errors.Main Outcome Measures:MVICs normalized to body mass were used to assess strength in the gluteal muscles of the dominant and nondominant limbs. Corticospinal excitability was assessed by means of active motor threshold (AMT) and motor-evoked potentials (MEP) elicited at 120% of AMT. The Landing Error Scoring System (LESS) was used to evaluate jump-landing biomechanics.Results:A moderate, positive correlation was found between dominant gluteus maximus MEP and LESS scores (r = .562, P = .029). No other significant correlations were observed for MVIC, AMT, or MEP for the gluteus maximus and gluteus medius, regardless of limb.Conclusions:The findings suggest a moderate relationship between dominant gluteus maximus corticospinal excitability and a clinical measure of jump-landing biomechanics. Further research is required to substantiate the findings and expand our understanding of the central nervous system’s role in athletic movement.

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