Plasma hormones, muscle mass and strength in resistance-trained postmenopausal women

Objective: To associate changes of body composition, muscle strength (MS) and plasma hormones (PH) in resistance-training protocol in sedentary postmenopausal women (PMW).Design: This randomized controlled trial, Brazilian 43 PMW (45-70-year-old) able for physical exercises were selected after they have accomplished medical and ethical criteria. They were assigned in two groups: RT, resistance training (n = 22); and CT, not trained control (n = 2 1); with supervision sessions of two to three exercise for large and one exercise for smaller groups in three series of 8-12 rep. (60-80% 1RM) for each exercise. The training period lasted 16 weeks and was preceded by low-load exercise (40-50% 1RM) adaptation period of 4 weeks (3/(times week)). Body weight, height, body mass index (BMI), and composition (BIA) along with fast-PH (FSH, LH, estrachol, cortisol, IGF-1 and testosterone) were assessed before (MO) and after (M 16) the 4 weeks period with the MS (1RM) determined also at 8 weeks (W). The values were correlated by Person's test and the means compared by Student's t-test and ANOVA.Results: At baseline both groups were similar in age, time of PMW, body composition, MS and fast-PH. However after 16 weeks, RT presented higher BMI (2. 1 %), IGF- 1 (37.8%) and MM gain (1.8 +/- 0.8 kg) than CT. MM correlated positively with IGF-1 (r = 0.45, p < 0.05) and MS progressively increased in all exercise greater in pectoral than legs and upper arms.Conclusion: Former sedentary postmenopausal women submitted to resistance training gained MM and MS irrespectively of fat mass changes but significantly associated with IGF-1 increase. (C) 2008 Elsevier B.V. All rights reserved.

BORN-INFELD ELECTRODYNAMICS and EULER-HEISENBERG-LIKE MODEL: OUTSTANDING EXAMPLES of THE LACK of COMMUTATIVITY AMONG QUANTIZED TRUNCATED ACTIONS and TRUNCATED QUANTIZED ACTIONS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Creatine but not betaine supplementation increases muscle phosphorylcreatine content and strength performance

We aimed to investigate the role of betaine supplementation on muscle phosphorylcreatine (PCr) content and strength performance in untrained subjects. Additionally, we compared the ergogenic and physiological responses to betaine versus creatine supplementation. Finally, we also tested the possible additive effects of creatine and betaine supplementation. This was a double-blind, randomized, placebo-controlled study. Subjects were assigned to receive betaine (BET; 2 g/day), creatine (CR; 20 g/day), betaine plus creatine (BET + CR; 2 + 20 g/day, respectively) or placebo (PL). At baseline and after 10 days of supplementation, we assessed muscle strength and power, muscle PCr content, and body composition. The CR and BET + CR groups presented greater increase in muscle PCr content than PL ( = 0.004 and = 0.006, respectively). PCr content was comparable between BET versus PL ( = 0.78) and CR versus BET + CR ( = 0.99). CR and BET + CR presented greater muscle power output than PL in the squat exercise following supplementation ( = 0.003 and = 0.041, respectively). Similarly, bench press average power was significantly greater for the CR-supplemented groups. CR and BET + CR groups also showed significant pre- to post-test increase in 1-RM squat and bench press (CR: = 0.027 and < 0.0001; BET + CR: = 0.03 and < 0.0001 for upper- and lower-body assessments, respectively) No significant differences for 1-RM strength and power were observed between BET versus PL and CR versus BET + CR. Body composition did not differ between the groups. In conclusion, we reported that betaine supplementation does not augment muscle PCr content. Furthermore, we showed that betaine supplementation combined or not with creatine supplementation does not affect strength and power performance in untrained subjects.

Effects of a combined aerobic and strength training program in youth patients with acute lymphoblastic leukemia

Cure rates of youth with Acute Lymphoblastic Leukemia (ALL) have increased in the past decades, but survivor's quality of life and physical fitness has become a growing concern. Although previous reports showed that resistance training is feasible and effective, we hypothesized that a more intense exercise program would also be feasible, but more beneficial than low- to moderate-intensity training programs. We aimed to examine the effects of an exercise program combining high-intensity resistance exercises and moderate-intensity aerobic exercises in young patients undergoing treatment for ALL. A quasi-experimental study was conducted. The patients (n = 6; 5-16 years of age) underwent a 12-week intra-hospital training program involving high-intensity strength exercises and aerobic exercise at 70% of the peak oxygen consumption. At baseline and after 12 weeks, we assessed sub-maximal strength (10 repetition-maximum), quality of life and possible adverse effects. A significant improvement was observed in the sub maximal strength for bench press (71%), lat pull down (50%), leg press (73%) and leg extension (64%) as a result of the training (p < 0.01). The parents' evaluations of their children's quality of life revealed an improvement in fatigue and general quality of life, but the children's self-reported quality of life was not changed. No adverse effects occurred. A 12-week in-hospital training program including high-intensity resistance exercises promotes marked strength improvements in patients during the maintenance phase of the treatment for Acute Lymphoblastic Leukemia without side-effects. Parents' evaluations of their children revealed an improvement in the quality of life.

Effects of acute physical exercise on executive functions: a comparison between aerobic and strength exercise

The aim of this study was to compare the effects of acute aerobic and strength exercises on selected executive functions. A counterbalanced, crossover, randomized trial was performed. Forty-two healthy women were randomly submitted to three different conditions: (1) aerobic exercise, (2) strength exercise, and (3) control condition. Before and after each condition, executive functions were measured by the Stroop Test and the Trail Making Test. Following the aerobic and strength sessions, the time to complete the Stroop "non-color word" and "color word" condition was lower when compared with that of the control session. The performance in the Trail Making Test was unchanged. In conclusion, both acute aerobic and strength exercises improve the executive functions. Nevertheless, this positive effect seems to be task and executive function dependent.

Comparison of multisensory and strength training for postural control in the elderly

Objective: The objective of this study was to analyze the efficacy of multisensory versus muscle strengthening to improve postural control in healthy community-dwelling elderly. Participants: We performed a single-blinded study with 46 community-dwelling elderly allocated to strength (GS, n = 23; 70.18 +/- 4.8 years 22 women and 1 man) and multisensory exercises groups (GM, n = 23; 68.8 +/- 5.9 years; 22 women and 1 man) for 12 weeks. Methods: We performed isokinetic evaluations of muscle groups in the ankle and foot including dorsiflexors, plantar flexors, inversion, and eversion. The oscillation of the center of pressure was assessed with a force platform. Results: The GM group presented a reduction in the oscillation (66.8 +/- 273.4 cm(2) to 11.1 +/- 11.6 cm(2); P = 0.02), which was not observed in the GS group. The GM group showed better results for the peak torque and work than the GS group, but without statistical significance. Conclusion: Although the GM group presented better results, it is not possible to state that one exercise regimen proved more efficacious than the other in improving balance control.

Dimorphism in Shell Shape and Strength in Two Species of Emydid Turtle

This study investigates the mechanical implications of shell shape differences between males and females of two North American turtle species: Chrysemys picta and Glyptemys insculpta. These species show patterns of sexual dimorphism that are common to many species of turtle. Females have wider and more highly domed shells, whereas males tend to have flatter, more streamlined shells. In addition, the males of many terrestrial species have concave plastra, most likely to accommodate the domed shells of the females while mating. The purpose of this study was to determine whether the known morphological differences in male and female turtle shells are also associated with differences in shell strength. Landmark coordinate data were collected from the shells of males and females of both species. These data were used to create digital models of each shell for finite-element (FE) analysis. FE models were generated by transforming a single base model of a turtle shell to match the shapes of each specimen examined in this study. All models were assigned the same material properties and restraints. Twelve load cases, each representing a predator’s bite at a different location on the carapace, were applied separately to the models. Subsequently, Von Mises stresses were extracted for each element of each model. Overall, the shells of females of both species exhibited significantly lower maximum and average stresses for a given load than those of their male counterparts. Male G. insculpta exhibited significant increases in stresses because of the concave shape of their plastra. We suggest that the mechanical implications of shell shape differences between males and females may have a large impact on many aspects of the biology of these turtle species.

High resolution quantitative computed tomography-based assessment of trabecular microstructure and strength estimates by finite-element analysis of the spine, but not DXA, reflects vertebral fracture status in men with glucocorticoid-induced osteoporosis

High-resolution quantitative computed tomography (HRQCT)-based analysis of spinal bone density and microstructure, finite element analysis (FEA), and DXA were used to investigate the vertebral bone status of men with glucocorticoid-induced osteoporosis (GIO). DXA of L1–L3 and total hip, QCT of L1–L3, and HRQCT of T12 were available for 73 men (54.6±14.0years) with GIO. Prevalent vertebral fracture status was evaluated on radiographs using a semi-quantitative (SQ) score (normal=0 to severe fracture=3), and the spinal deformity index (SDI) score (sum of SQ scores of T4 to L4 vertebrae). Thirty-one (42.4%) subjects had prevalent vertebral fractures. Cortical BMD (Ct.BMD) and thickness (Ct.Th), trabecular BMD (Tb.BMD), apparent trabecular bone volume fraction (app.BV/TV), and apparent trabecular separation (app.Tb.Sp) were analyzed by HRQCT. Stiffness and strength of T12 were computed by HRQCT-based nonlinear FEA for axial compression, anterior bending and axial torsion. In logistic regressions adjusted for age, glucocorticoid dose and osteoporosis treatment, Tb.BMD was most closely associated with vertebral fracture status (standardized odds ratio [sOR]: Tb.BMD T12: 4.05 [95% CI: 1.8–9.0], Tb.BMD L1–L3: 3.95 [1.8–8.9]). Strength divided by cross-sectional area for axial compression showed the most significant association with spine fracture status among FEA variables (2.56 [1.29–5.07]). SDI was best predicted by a microstructural model using Ct.Th and app.Tb.Sp (r2=0.57, p<0.001). Spinal or hip DXA measurements did not show significant associations with fracture status or severity. In this cross-sectional study of males with GIO, QCT, HRQCT-based measurements and FEA variables were superior to DXA in discriminating between patients of differing prevalent vertebral fracture status. A microstructural model combining aspects of cortical and trabecular bone reflected fracture severity most accurately.

Pelvic floor muscle activation and strength components influencing female urinary continence and stress incontinence: A systematic review

AIMS A better understanding of pelvic floor muscle (PFM) activation and strength components is a prerequisite to get better insight in PFM contraction mechanisms and develop more specific PFM-training regimens for female stress urinary incontinence (SUI) patients. The aim of this systematic review (2012:CRD42012002547) was to evaluate and summarize existing studies investigating PFM activation and strength components influencing female continence and SUI. METHODS PubMed, EMBASE, and Cochrane databases were systematically searched for literature from January 1980 to November 2013 for cross-sectional studies comparing female SUI patients with healthy controls and intervention studies with SUI patients reporting on the association between PFM activation and strength components and urine loss. Trial characteristics, evaluated PFM components, their definitions, measurement methods, study outcomes, as well as quality measures, based on the Cochrane risk of bias tool, were independently extracted. The high heterogeneity of the retrieved data made pooling of results impossible and therefore restricted the analysis to a systematic review. RESULTS Cross-sectional studies showed group differences in favor of the continent women compared to SUI patients for PFM activation or PFM maximal strength, mean strength or sustained contraction. All intervention studies showed an improvement of PFM strength and decrease in urine loss in SUI patients after physical therapy. CONCLUSIONS Higher PFM activation and strength components influence female continence positively. This systematic review underscored the need for a standardized PFM components' terminology (similar to rehabilitation and training science), standardized test procedures and well matched diagnostic instruments. Neurourol. Urodynam. © 2014 Wiley Periodicals, Inc.

Consolidation properties and strength characteristics of ODP Site 204-1244 sediments

Eight whole-core samples from Ocean Drilling Program Site 1244, Hydrate Ridge, Cascadia continental margin, were provided to Massachusetts Institute of Technology (Cambridge, Massachusetts, USA) for geotechnical characterization. The samples were collected from depths ranging from 5 to 136 meters below seafloor (mbsf). Seven of the eight whole-core samples were located within the gas hydrate stability zone, whereas the eighth sample was located in the free gas zone. Atterberg limits testing showed that the average liquid limit of the soil is 81% and the average plastic limit is 38%, giving an average plasticity index of 43%. The liquid limit is sensitive to oven drying, shown by a drop in liquid limit to 64% when tests were performed on an oven-dried sample. Loss on ignition averages 5.45 wt%. Constant rate of strain consolidation (CRSC) tests were performed to obtain the compression characteristics of the soil, as well as to determine the stress history of the site. CRSC tests also provided hydraulic conductivity and coefficient of consolidation characteristics for these sediments. The compression ratio (Cc) ranges from 0.340 to 0.704 (average = 0.568). Cc is fairly constant to a depth of 79 mbsf, after which Cc decreases downhole. The recompression ratio (Cr) ranges from 0.035 to 0.064 (average = 0.052). Cr is constant throughout the depth range. In situ hydraulic conductivity varies between 1.5 x 10**-7 and 3 x 10**-8 cm/s and shows no trend with depth. Ko-consolidated undrained compression/extension (CKoUC/E) tests were also performed to determine the peak undrained shear strength, stress-strain curve, and friction angle. The normalized undrained strength ranges from 0.29 to 0.35. The friction angle ranges from 27 to 37. Because of the limited amount of soil, CRSC and CKoUC/E tests were also conducted on resedimented specimens.

Consolidation and strength assessment of ODP Leg 123 sediments

Twenty-one samples, ranging in depth from 0 to 150 meters below seafloor (mbsf), were obtained from Leg 123 Sites 765 and 766. All samples were tested for Atterberg limits: 14 for laboratory vane shear strength and seven for uniaxial consolidation. Based on the determined Atterberg limits, along with shipboard measurements of water content, the sediment appears to be underconsolidated from 0 to 40 mbsf at Site 765 and from 0 to 80 mbsf at Site 766. Normal consolidation trends were observed for the sediments below these depths. Vane shear strengths, when compared with calculated values for a normally consolidated clay, indicate underconsolidated sediment at both sites. However, the use of Atterberg limit and vane shear strength data to assess consolidation state is complicated by the presence of silt-sized calcium carbonate in the form of nannofossil ooze. Thus, uniaxial-consolidation test data were analyzed to determine the overconsolidation ratios (OCR) and sediment compressibilities. OCR values were found to be less than one (underconsolidated) at both sites, using two separate methods of analysis.