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1.
Medicine (Baltimore) ; 100(39): e27383, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34596159

RESUMEN

ABSTRACT: The aim of this study was to develop an age and soccer-specific regression equation to estimate the peak power of children aged 12-14 from the height of their vertical jumps using a large sample (n = 188). This study included 188 male soccer players (age, 12.6 ±â€Š0.55; height, 153.31 ±â€Š8.38 cm; and body weight, 43.65 ±â€Š7.58 kg). Their actual peak power values obtained from vertical jumps were recorded using a force platform. The body weights of the participants were measured using Tanita. A regression model was developed using body weight and vertical jump values. All data were analyzed with the IBM SPSS (version 21) statistical analysis program. A multiple linear regression model was used to generate the best estimation of peak power. In this regression model, Power = -1714,116 + [(47.788 ∗ body weight (kg)] + [(58,976 ∗ Countermovement jump height (cm)]. Actual peak power is highly predictable for 12-14-year-old football players. In line with the new model, the actual peak power values obtained in this study were close to the estimated peak power values obtained with the Tufano formula. This may be because of the larger sample size and the same branch used for both equation models.


Asunto(s)
Fuerza Muscular/fisiología , Fútbol/fisiología , Adolescente , Peso Corporal , Niño , Estudios Transversales , Ejercicio Físico/fisiología , Humanos , Masculino
2.
Artículo en Inglés | MEDLINE | ID: mdl-34639604

RESUMEN

This study aimed to investigate the effects of online physical education classes, using Tabata training, on middle school students' physical fitness. Fifty-four adolescents were randomly assigned to either the asynchronous online class group (AOCG, n = 24, age: 15.8 ± 0.4 years) or the synchronous online class group (SOCG, n = 24 age: 15.9 ± 0.3 years). The online physical education class lasted two days per week for 10 weeks. Recorded video lectures were conducted for the AOCG, and Tabata training for the SOCG, as real-time lecture methods. Baseline and post-online physical education class measures included muscular strength, muscular endurance, flexibility, balance, and cardiorespiratory fitness tests. The results showed that the synchronous online physical education class had a positive effect on the improvement of muscle mass, ankle strength (dorsiflexion), hip strength (abduction, flexion, extension, and external rotation), knee strength (extension and flexion), and balance (Y-balance test) in adolescents. These findings suggest that the physical fitness of adolescents can be sufficiently improved through appropriate online physical education class methods. Further research should focus on developing and evaluating different types of exercises for synchronous online physical education classes as a precautionary measure for the second wave of COVID-19.


Asunto(s)
COVID-19 , Educación y Entrenamiento Físico , Adolescente , Humanos , Fuerza Muscular , Aptitud Física , SARS-CoV-2
3.
J Sports Med Phys Fitness ; 61(10): 1333-1338, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34652086

RESUMEN

BACKGROUND: The aim of the study is to compare a 16-week tai chi and Iyengar yoga program effects on muscle strength, static and dynamic balance, and balance confidence in elderly people. METHODS: A total of 48 participants (≥60 years old) without mobility-impairing neurological disease, dementia, cardiovascular disease/symptoms during moderate exercise, poorly controlled hypertension, or balance-impairing drug use. Participants were divided into a tai chi group, an Iyengar yoga group, and a control group (eight males and eight females per group), using a restricted randomization scheme generated by software. While the former two undertook 16-week exercise programs, the control group received general education. Maximum concentric strength was measured with an isokinetic dynamometer. The one-legged stand with eyes closed, "8 feet up and go," and Activities-specific Balance Confidence (ABC) scale were used to assess static balance, dynamic balance, and balance confidence in daily activities, respectively. RESULTS: Both programs improved all measures significantly with tai chi being more effective for increasing knee flexor strength (P=0.045) and extensor strength (P=0.032) and ABC score (P=0.034); Iyengar yoga was more effective for improving static balance (P=0.014) and dynamic balance (P=0.025; all P values here vs. the other program). CONCLUSIONS: Tai chi and Iyengar yoga can improve strength, balance, and balance confidence among older people. Both are suitable exercise choices for older adults.


Asunto(s)
Tai Ji , Yoga , Anciano , Femenino , Humanos , Rodilla , Masculino , Persona de Mediana Edad , Fuerza Muscular , Equilibrio Postural
4.
J Sports Med Phys Fitness ; 61(9): 1202-1207, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34610728

RESUMEN

BACKGROUND: We examined the relationships between jump performance measures, sprint tests, and 100-m competition times in 11 top-level sprinters during two successive competitive 4-week mesocycles. METHODS: Physical tests were performed 7-12 days before 3 sequential competitions. Sprinters completed standing long jump, squat and countermovement jumps, and 60-m sprint tests on each occasion. A repeated measures analysis of variance was used to compare the physical assessments and actual competition results among the three moments. A Pearson product-moment correlation coefficient was used to analyze the relationships between the multiple variables over the consecutive mesocycles. Significance level was set at P<0.05. RESULTS: No significant differences were observed among the periods for any jump or sprint performance measure (ES ranging from 0.02 to 0.33; P>0.05). Very large to nearly perfect correlations were observed for all sprint and jump variables and 100-m dash times in the three moments analyzed (P<0.05). CONCLUSIONS: Our data indicate that simple jump measures can be prospectively used to monitor sprint performance. Notably, the standing long jump test was the most consistently related to 100-m time. This simple strategy may help track and field coaches to better adjust the competitive approach of their sprinters, thus optimizing their peak performance.


Asunto(s)
Rendimiento Atlético , Carrera , Atletismo , Prueba de Esfuerzo , Humanos , Fuerza Muscular
5.
J Sports Med Phys Fitness ; 61(9): 1219-1225, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34610729

RESUMEN

BACKGROUND: Creatine supplementation, in close proximity to resistance training sessions, may be an important strategy to augment muscle accretion and strength. The purpose of this study was to examine the effects of creatine supplementation immediately before compared to immediately after unilateral resistance training on hypertrophy and strength. METHODS: Using a counter-balanced, double-blind, repeated measures within-subject design, ten recreationally active participants (7 males; 3 females; age: 23±5 years; height: 174±9 cm; body mass: 73.5±9.7 kg) were randomized to supplement with creatine monohydrate (0.1 g/kg of body mass) immediately before and placebo immediately after training one side of the body and placebo immediately before and creatine immediately after training the other side of the body on alternate days. Resistance training consisted of elbow flexion and knee extension (3-6 sets at 80% 1-repetition maximum [1-RM]) for 8 weeks. Prior to and following training, muscle thickness (elbow flexors and leg extensors; ultrasonography) and strength (1-RM for the elbow flexors and knee extensors) was assessed. RESULTS: There was a significant increase over time for muscle thickness, strength, and relative strength (P<0.01), with no differences between creatine ingestion strategies. Total training volume performed was similar between conditions (P=0.56). CONCLUSIONS: Creatine supplementation, immediately before or immediately after unilateral resistance training, produces similar gains in muscle hypertrophy and strength in young adults.


Asunto(s)
Creatina , Entrenamiento de Fuerza , Adolescente , Adulto , Suplementos Dietéticos , Femenino , Humanos , Hipertrofia , Masculino , Fuerza Muscular , Músculo Esquelético , Adulto Joven
6.
J Int Soc Sports Nutr ; 18(1): 66, 2021 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-34625064

RESUMEN

BACKGROUND: Previous narrative reviews have concluded that dietary nitrate (NO3-) improves maximal neuromuscular power in humans. This conclusion, however, was based on a limited number of studies, and no attempt has been made to quantify the exact magnitude of this beneficial effect. Such information would help ensure adequate statistical power in future studies and could help place the effects of dietary NO3- on various aspects of exercise performance (i.e., endurance vs. strength vs. power) in better context. We therefore undertook a systematic review and individual participant data meta-analysis to quantify the effects of NO3- supplementation on human muscle power. METHODS: The literature was searched using a strategy developed by a health sciences librarian. Data sources included Medline Ovid, Embase, SPORTDiscus, Scopus, Clinicaltrials.gov , and Google Scholar. Studies were included if they used a randomized, double-blind, placebo-controlled, crossover experimental design to measure the effects of dietary NO3- on maximal power during exercise in the non-fatigued state and the within-subject correlation could be determined from data in the published manuscript or obtained from the authors. RESULTS: Nineteen studies of a total of 268 participants (218 men, 50 women) met the criteria for inclusion. The overall effect size (ES; Hedge's g) calculated using a fixed effects model was 0.42 (95% confidence interval (CI) 0.29, 0.56; p = 6.310 × 10- 11). There was limited heterogeneity between studies (i.e., I2 = 22.79%, H2 = 1.30, p = 0.3460). The ES estimated using a random effects model was therefore similar (i.e., 0.45, 95% CI 0.30, 0.61; p = 1.064 × 10- 9). Sub-group analyses revealed no significant differences due to subject age, sex, or test modality (i.e., small vs. large muscle mass exercise). However, the ES in studies using an acute dose (i.e., 0.54, 95% CI 0.37, 0.71; p = 6.774 × 10- 12) was greater (p = 0.0211) than in studies using a multiple dose regimen (i.e., 0.22, 95% CI 0.01, 0.43; p = 0.003630). CONCLUSIONS: Acute or chronic dietary NO3- intake significantly increases maximal muscle power in humans. The magnitude of this effect-on average, ~ 5%-is likely to be of considerable practical and clinical importance.


Asunto(s)
Rendimiento Atlético/fisiología , Suplementos Dietéticos , Fuerza Muscular , Nitratos/administración & dosificación , Método Doble Ciego , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto
7.
Artículo en Inglés | MEDLINE | ID: mdl-34574662

RESUMEN

The COVID-19 pandemic has produced a major disruption for professional football leagues that has affected the physical preparation of both football players and referees. In Spain, health authorities decreed home confinement for eight weeks, supressing the normal training routines of professional referees. After home confinement, referees had four weeks to retrain as the national football league was set to resume matches to complete the 11 games remaining. The aim of the present investigation was to assess changes in eccentric hamstring muscle strength during football competition suspension/resumption due to the COVID-19 pandemic in 21 professional football referees (mean ± SD, age: 33.4 ± 5.1 years; height: 182.4 ± 5.0 cm; body mass: 75.1 ± 4.4 kg). Eccentric hamstring muscle strength was measured with the Nordic hamstring exercise at four time points. During home confinement, referees presented the lowest value of bilateral eccentric muscle strength (300 ± 14 N). Eccentric muscle strength increased by 13.2 ± 3.7% one week after the end of home confinement (339 ± 16 N; p = 0.001, effect size (ES) = 2.8) and remained stable before the first match (343 ± 17 N; p = 0.001, ES = 3.1) and after the end of the national league (328 ± 13 N; p = 0.001, ES = 2.0). In summary, home confinement produced detraining effects in professional football referees associated with hamstring muscle weakness. In this regard, strength-based activities with body loads may be insufficient to avoid muscle weakness and other means (e.g., weights) may be necessary to maintain muscle strength. However, the 4-weeks retraining period was sufficient to resolve hamstring muscle weakness induced by the restrictions of home confinement. This information may be helpful in the case of future sport competition suspension or home quarantine due to new waves of COVID-19 pandemic.


Asunto(s)
COVID-19 , Fútbol Americano , Músculos Isquiosurales , Fútbol , Adulto , Humanos , Fuerza Muscular , Pandemias , Estudios Prospectivos , SARS-CoV-2
8.
Life Sci ; 284: 119924, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34480935

RESUMEN

AIMS: The present study aimed to verify the effects of resistance training (RT) and successive detraining on body composition, muscle strength and lipid profile as primary outcome, and the oxidative stress and inflammatory markers as second outcome of postmenopausal Breast Cancer (BC) survivors undergoing tamoxifen (TA). MAIN METHODS: Fourteen postmenopausal BC survivors underwent 12 weeks of resistance exercise training and subsequently 12 weeks of detraining. Anthropometric parameters, lipid profile, muscle strength, inflammatory cytokines and the oxidative stress markers, were assessed before, after the training period and after detraining period. KEY FINDINGS: One-way ANOVA showed that fat mass decrease (39.4 ± 6.9 to 37.7 ± 6.8%) and free-fat mass increase (39.3 ± 4.9 to 40.3 ± 5.6%) after RT. Muscle strength increased in response to training but decreased after the detraining period. Triglycerides (156 ± 45 to 123 ± 43 mg/dL) and total cholesterol (202 ± 13 to 186 ± 16 mg/dL) decreased after the RT and HDL-cholesterol (47 ± 9 to 56 ± 9 mg/dL) increased after RT and remained higher (53 ± 10 mg/dL) than after detraining. IL-6 increases (24.65 ± 10.85 to 41.42 ± 22.88 pg/mL) and IL-17 (2.42 ± 0.32 to 1.69 ± 0.19 pg/mL), TBARS (1.91 ± 0.19 to 1.03 ± 0.1 µmol/L), SOD (24.65 ± 10.85 to 41.42 ± 22.88 U/gHb) and Catalase activity (445.9 ± 113.0 to 345.8 ± 81.7 k/gHb·s) reduced after RT and remained lower after detraining. SIGNIFICANCE: Resistance exercise training improves health markers of BC survivors undergoing TA and detraining are not sufficient to reverse the positive effects in oxidative stress markers.


Asunto(s)
Biomarcadores de Tumor/sangre , Composición Corporal , Neoplasias de la Mama/fisiopatología , Supervivientes de Cáncer , Ejercicio Físico , Lípidos/sangre , Fuerza Muscular , Tamoxifeno/uso terapéutico , Adulto , Anciano , Composición Corporal/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Humanos , Inflamación/patología , Persona de Mediana Edad , Fuerza Muscular/efectos de los fármacos , Tamoxifeno/farmacología
9.
Eur J Phys Rehabil Med ; 57(4): 607-619, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34519194

RESUMEN

BACKGROUND: More than 40% of individuals with whiplash injury experience persistent neck pain and disability years later, called whiplash-associated disorders (WAD). A randomized controlled trial evaluated three exercise interventions in WAD and found that neck-specific exercise (NSE) and NSE with a behavioral approach (NSEB) significantly improve disability compared to prescribed physical activity (PPA). However, the relationship between neck-related function and disability is inconclusive and needs to be further investigated. AIM: The present study compares the effect of NSE, NSEB, and PPA on neck muscle endurance (NME), active cervical range of motion (AROM), grip strength, and pain intensity immediately before and after the physical tests, and neck disability in individuals who are below or above the cut-off for normative reference values regarding NME, AROM, and grip strength. DESIGN: Follow-up to a multicenter randomized clinical trial. SETTING: Primary healthcare centers and hospital outpatient services. POPULATION: The selected population of this study included 216 patients with persistent WAD grades II and III. METHODS: This is a secondary analysis including 12 months' follow-up. NME, AROM, grip strength, pain, and self-reported disability were recorded at baseline, 3, 6, and 12 months. Linear mixed models were used, and sub-group analyses evaluated by non-parametric tests. RESULTS: NSE and NSEB resulted in greater improvements compared to PPA (P<0.01) in ventral (only males) and dorsal NME, AROM, and pain intensity during testing. We found no significant between-group differences in grip strength and no significant differences between the NSE and NSEB groups. Improvement in disability was seen at the 12-month follow-up of NSE and/or NSEB for individuals both below and above the cut-off reference values for NME and AROM. Individuals in the PPA group below the reference values for NME and AROM reported increasing disability at 12 months compared to baseline. CONCLUSIONS: The results suggest that neck-specific exercises (i.e., NSE, NSEB) improve clinical function and decrease disability in chronic WAD compared to PPA, but PPA can increase disability for patients with low neck-related function. CLINICAL REHABILITATION IMPACT: Higher neck-related function seems to be important for reduced disability in persistent WAD grades II and III. Neck-specific exercises could lead to higher neck-related function.


Asunto(s)
Terapia Cognitivo-Conductual/métodos , Personas con Discapacidad/rehabilitación , Terapia por Ejercicio/métodos , Ejercicio Físico/fisiología , Músculos del Cuello/fisiopatología , Lesiones por Latigazo Cervical/fisiopatología , Lesiones por Latigazo Cervical/rehabilitación , Adulto , Enfermedad Crónica/rehabilitación , Terapia Combinada , Evaluación de la Discapacidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fuerza Muscular/fisiología , Dimensión del Dolor , Rango del Movimiento Articular/fisiología
10.
Int J Behav Nutr Phys Act ; 18(1): 120, 2021 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-34496869

RESUMEN

INTRODUCTION: Decline in physical function varies substantially across older individuals due to several extrinsic modifiable factors such as dietary patterns, physical activity and social support. We aimed to determine the association of these factors and their interaction with mobility and muscle strength decline. METHODS: We analyzed data from 1686 functionally healthy individuals aged 60 + from the population-based Swedish National study on Aging and Care in Kungsholmen (SNAC-K). The Mediterranean Diet Score (MDS) was calculated based on a validated food frequency questionnaire. Self-reported physical activity was categorized based on current recommendations, and social support was measured according to participants' perceived material and psychological support from relatives and friends. Participants' physical function was assessed over 12 years through changes in walking speed (m/s) and chair stand time (s). Linear mixed models adjusted for socio-demographic and clinical factors were used. In order to explore the combined effect of the different exposures, two indicator variables were created by cross-classifying individuals' levels of Mediterranean diet adherence and social support or physical activity. RESULTS: Participants with a high adherence to Mediterranean diet were primarily < 78 years (82.3%), women (56.1%), married (61.1%), with university education (52.8%), high levels of social support (39.3%) and health-enhancing levels of physical activity (51.5%). A one-point increase in MDS (score range 0-9) was associated with less annual deterioration in walking speed (ß*time[year] = 0.001; p = 0.024) and chair-stand time (ß*time[year] = -0.014; p = 0.008). The potential protective effect of Mediterranean diet was highest among participants reporting high social support (ß*time[year] = -0.065, p = 0.026 for chair stands) and high physical activity (ß*time[year] = 0.010, p = 0.001 for walking speed), beyond the effect of each exposure individually. CONCLUSION: A higher adherence to Mediterranean diet, especially in combination with recommended levels of physical activity and high social support, may contribute to delay the decline in physical function observed with aging.


Asunto(s)
Dieta Mediterránea , Ejercicio Físico , Femenino , Estado de Salud , Humanos , Fuerza Muscular , Apoyo Social
11.
J Vis Exp ; (175)2021 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-34542541

RESUMEN

Reliable assessment of skeletal muscle strength is arguably the most important outcome measure in neuromuscular and musculoskeletal disease and injury studies, particularly when evaluating regenerative therapies' efficacy. Additionally, a critical aspect of translating many regenerative therapies is the demonstration of scalability and effectiveness in a large animal model. Various physiological preparations have been established to evaluate intrinsic muscle function properties in basic science studies, primarily in small animal models. The practices may be categorized as: in vitro (isolated fibers, fiber bundles, or whole muscle), in situ (muscle with intact vascularization and innervation but distal tendon attached to a force transducer), and in vivo (structures of the muscle or muscle unit remain intact). There are strengths and weaknesses to each of these preparations; however, a clear advantage of in vivo strength testing is the ability to perform repeated measurements in the same animal. Herein, the materials and methods to reliably assess isometric torque produced by the hindlimb dorsiflexor muscles in vivo in response to standard peroneal electrical stimulation in anesthetized pigs are presented.


Asunto(s)
Fuerza Muscular , Músculo Esquelético , Animales , Miembro Posterior , Contracción Isométrica , Extremidad Inferior , Porcinos , Torque
12.
Medicine (Baltimore) ; 100(35): e27126, 2021 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-34477156

RESUMEN

ABSTRACT: Currently no research is available on muscle and functional performance of chronic obstructive pulmonary disease (COPD) patients with type 2 diabetes (T2DM) in China, even though both diseases have been reported to damage motor function.This single-center prospective study involves 55 males with COPD and T2DM and 46 males with COPD. Lung function, muscle strength and endurance of the upper limbs, and quadriceps strength of both legs were assessed using instruments. The 6-min walk (6MW) test was performed to evaluate physical performance.Between the two groups, respiratory function of COPD patients with T2DM was worse than in those without (P < .05). Mean handgrip strength and muscle endurance of upper limbs and mean quadriceps strength at both 60°/s and 120°/s in COPD males with T2DM was also significantly less (P < .05). Mean 6MW distances of COPD patients with T2DM were significantly worse (P < .05), and mean pulse rate (PR) increments of COPD patients with T2DM in 6MW test were significantly higher (P < .05).The combination of COPD and T2DM not only brings one more chronic disease to elderly patients but also significantly affects muscle strength and endurance as well as physical performance. Accordingly, in the management of chronic diseases, we recommend that clinicians as well as patients themselves actively control blood sugar and review them regularly with a view to reducing adverse effects on physical performance.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Rendimiento Físico Funcional , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Anciano , Humanos , Masculino , Persona de Mediana Edad , Fuerza Muscular , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Músculo Cuádriceps/fisiopatología
13.
J Athl Train ; 56(9): 937-944, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34530434

RESUMEN

Muscle weakness and atrophy are common impairments after musculoskeletal injury. Blood flow restriction (BFR) training offers the ability to mitigate weakness and atrophy without overloading healing tissues. It appears to be a safe and effective approach to therapeutic exercise in sports medicine environments. This approach requires consideration of a wide range of factors, and the purpose of our article is to provide insights into proposed mechanisms of effectiveness, safety considerations, application guidelines, and clinical recommendations for BFR training after musculoskeletal injury. Whereas training with higher loads produces the most substantial increases in strength and hypertrophy, BFR training appears to be a reasonable option for bridging earlier phases of rehabilitation when higher loads may not be tolerated by the patient and later stages that are consistent with return to sport.


Asunto(s)
Entrenamiento de Fuerza , Terapia por Ejercicio , Humanos , Fuerza Muscular , Músculo Esquelético , Flujo Sanguíneo Regional
14.
J Int Soc Sports Nutr ; 18(1): 63, 2021 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-34565388

RESUMEN

BACKGROUND: Carbohydrate (CHO) and caffeine (CAF) mouth rinsing have been shown to enhance endurance and sprint performance. However, the effects of CHO and CAF mouth rinsing on muscular and cognitive performance in comparison between male and female athletes are less well-established. The aim of this study was to examine the effect of CHO and CAF rinsing on squat and bench press 1 repetition maximum (1-RM) strength, 3 sets of 40% of 1-RM muscular endurance and cognitive performance in both male and female athletes. METHODS: Thirteen male and fourteen female resistance-trained participants completed four testing sessions following the rinsing of 25 ml of i) 6% of CHO (1.5 g); ii) 2% CAF (500 mg), iii) combined CHO and CAF (CHOCAF) solutions or iv) water (PLA) for 10 s. Heart rate (HR), felt arousal (FA), ratings of perceived exertion (RPE) and glucose (GLU) were recorded throughout the test protocol. RESULTS: There were no significant differences in squat and bench press 1-RM, HR, RPE and GLU (p > 0.05) for males and females, respectively. FA was significantly increased with CAF (p = 0.04, p = 0.01) and CHOCAF (p = 0.03, p = 0.01) condition in both males and females, respectively. Squat endurance performance in the first set was significantly increased with CHOCAF condition compared to PLA in both males (p = 0.01) and females (p = 0.02). Bench press endurance was similar for all conditions in both genders (p > 0.05). Cognitive performance was significantly increased with CHOCAF compared to PLA in males (p = 0.03) and females (p = 0.02). CONCLUSION: Combined CHO and CAF mouth rinsing significantly improved lower body muscular endurance and cognitive performance in both males and females.


Asunto(s)
Rendimiento Atlético , Cafeína/administración & dosificación , Cognición/efectos de los fármacos , Carbohidratos de la Dieta/administración & dosificación , Antisépticos Bucales , Fuerza Muscular/efectos de los fármacos , Resistencia Física/efectos de los fármacos , Adulto , Femenino , Voluntarios Sanos , Humanos , Masculino , Factores Sexuales , Adulto Joven
15.
J Athl Train ; 56(9): 952-959, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34530433

RESUMEN

CONTEXT: The Nordic hamstring exercise (NHE) is known to reduce hamstrings injury risk in athletes. To optimize the NHE, it is important to understand how acute resistance-training variables influence its performance. OBJECTIVE: To examine the effects of different interset rest intervals (ISRIs) on force indices during performance of the NHE. DESIGN: Crossover study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Ten well-trained, young, male, team-sport athletes (age = 20.7 ± 2.3 years, height = 179.4 ± 5.5 cm, mass = 83.9 ± 12.4 kg). INTERVENTION(S): Participants performed 2 sets of 6 repetitions of the NHE with either a 1- or 3-minute ISRI. All sets were performed using the NordBord. MAIN OUTCOMES MEASURE(S): Peak force (newtons), average force (newtons), percentage maintenance, and percentage decline were recorded for both the dominant and nondominant limbs, and interlimb force asymmetries (percentages) were calculated. RESULTS: No interactions or main effects (P > .05) were present between conditions or sets for any variables. However, individual repetitions showed reductions (P< .05; effect size range = 0.58-1.28) in peak force from repetition 4 onward. CONCLUSIONS: Our findings suggest that a 1-minute ISRI was sufficient to maintain force-production qualities and interlimb asymmetries between sets during the NHE in well-trained athletes. Nonetheless, practitioners should be aware of the potentially large decrements in peak force production that may occur within the set.


Asunto(s)
Músculos Isquiosurales , Entrenamiento de Fuerza , Atletas , Estudios Cruzados , Ejercicio Físico , Humanos , Masculino , Fuerza Muscular , Adulto Joven
16.
BMC Musculoskelet Disord ; 22(1): 827, 2021 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-34579703

RESUMEN

BACKGROUND: Identifying populations with poor muscle recovery after total hip arthroplasty (THA) is important for postoperative physical therapy. Preoperative muscle strength is a strong factor that determines postoperative muscle strength. However, this effect may depend on other factors. Thus, predictive models with interaction terms are important for accurately predicting postoperative muscle strength. This study aimed to develop a predictive model for lower muscle strength 12 months after THA which incorporates interaction terms. METHODS: Subjects were female patients with hip osteoarthritis who underwent unilateral THA. Patients with locomotor disorders, neurological disorders, or postoperative complications were excluded. Hip abductor and knee extensor strength were measured, and a generalized linear model approach with preoperative muscle strength, age, body weight, height, disease duration, physical activity, and leg extension as explanatory variables was used to identify factors that determine muscle strength 12 months after THA. Models with interaction terms between preoperative muscle strength and other explanatory variables were also examined. RESULTS: A total of 82 patients were analyzed. Preoperative muscle strength, age, body weight, physical activity, and disease duration were extracted as factors that significantly and independently determine hip abductor and knee extensor strength. The interaction term between preoperative muscle strength and age was identified as a factor that significantly determines knee extensor strength. Regression coefficients for preoperative knee extensor strength and postoperative muscle strength were significant when age was +1 SD, but not when age was -1 SD. CONCLUSIONS: The predictive model demonstrated that lower muscle strength 12 months after THA is determined by preoperative muscle strength, age, weight, physical activity, disease duration, and preoperative muscle strength, with the effect of preoperative muscle strength on knee extensor strength being dependent on age. When predicting postoperative knee extensor strength using preoperative muscle strength, it is important to consider the effect of age.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Osteoartritis de la Cadera , Artroplastia de Reemplazo de Cadera/efectos adversos , Femenino , Humanos , Lactante , Rodilla , Articulación de la Rodilla , Fuerza Muscular , Osteoartritis de la Cadera/cirugía
17.
Arthroscopy ; 37(9): 2870-2872, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34481627

RESUMEN

Blood flow restriction (BFR) training continues to look promising to try and maintain muscle mass or to rebuild muscle mass and strength after injury or surgery. Because additional potential benefits include pain control, increased gene expression (leading to atrophy reduction), and muscle excitation, our use of the modality favors earlier over middle- or late-phase postoperative use. We initiate BFR therapy 2-14 days postoperatively, often with reduced cuff pressure in the first several sessions before increasing to the recommended therapeutic occlusion level. We have observed the greatest benefit for individuals who are non-weight-bearing for 6 to 8 weeks and who may have more postoperative restrictions due to the nature of the surgery. Compared with the opposite thigh, we have seen instances in which quadriceps girth has been preserved, although not increased, following the non-weight-bearing period. Ideally, we use 1 to 3 low-load resistance training exercises per session at least 2 times per week for 6 weeks. We also employ BFR following osteotomy or any procedure where bone drilling is used, as researchers have observed improved bone health. Additional benefits relevant to the early postoperative phase, such as effusion and pain reduction, have not been clearly established. Anecdotally, we have seen effusion levels temporarily increase during treatment but then resolve to baseline within 30 to 60 minutes of tourniquet deflation. Further high-level research is necessary to objectively validate BFR use and which patients may best benefit from it.


Asunto(s)
Fuerza Muscular , Entrenamiento de Fuerza , Terapia por Ejercicio , Humanos , Músculo Cuádriceps , Flujo Sanguíneo Regional
18.
BMC Geriatr ; 21(1): 485, 2021 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-34488651

RESUMEN

BACKGROUND: Higher muscle echo intensity (EI) reflects higher content of fat and/or connective tissue within skeletal muscle, eventually inducing lower muscle strength, physical dysfunction, and metabolic impairment. Continuous exercise decreases muscle EI in older individuals; however, it is not well understood how several months' rehabilitation exercise affects gradation-based EI. The purpose of this study was to investigate the effects of 6 months of rehabilitation exercise on gradation-based higher and lower EI in older men and women. METHODS: Twenty-seven men and women (7 men, 20 women; age, 75.6 ± 6.4 years; height, 154.3 ± 8.5 cm; weight, 55.8 ± 9.7 kg) participated in this study. This study was a one-group before-and-after trial. They needed long-term care for activities of daily living. They performed rehabilitation exercises consisting of resistance exercises using a hydraulic resistance machine, stretching, and aerobic exercises using a recumbent bicycle once or twice a week for 6 months. B-mode ultrasonographic transverse image was taken from thigh muscles, e.g., rectus femoris, vastus lateralis, and biceps femoris. We calculated gradation-based cross-sectional area (CSA) from thigh muscles by dividing 256 greyscale level to 10 different components levels (e.g., 0-24, 25-49, 50-74, …, 200-224 and 225-249 a.u.). RESULTS: Lowest EI (e.g., 0-24 a.u.) CSA of thigh muscle was significantly increased after the exercise (0.3 ± 0.3 to 1.0 ± 0.8 cm2; P < 0.05). Middle to higher EI (e.g., 50-74, 75-99, 100-124, 125-149, 150-174, 175-199 and 200-224 a.u.) CSAs were significantly decreased from 23.0 to 68.7% after the exercise (P < 0.05). CONCLUSIONS: Several months' rehabilitation exercise affected both lower and higher EI in older men and women. This result suggests that rehabilitation exercise changes muscle composition by increasing contractile muscle tissue and decreasing fat and connective tissues.


Asunto(s)
Actividades Cotidianas , Músculo Esquelético , Anciano , Anciano de 80 o más Años , Terapia por Ejercicio , Femenino , Humanos , Masculino , Fuerza Muscular , Músculo Esquelético/diagnóstico por imagen , Ultrasonografía
19.
J Pak Med Assoc ; 71(9): 2173-2176, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34580509

RESUMEN

OBJECTIVE: To determine the effect of blood flow restriction with strengthening exercises on knee osteoarthritis patients. Method: The case-control study was conducted at the Department of Physical Medicine and Rehabilitation, Combined Military Hospital, Okara, Pakistan, from June to December 2018, and comprised knee osteoarthritis patients who were assigned to two equal groups. The cases in Group A received strengthening exercises with blood flow restriction, while the controls in Group B received strengthening exercises without blood flow restriction. Both groups were given 4 sessions of treatment per week with 5-minute warm-up on a stationary bike for 4 weeks. Outcome was measured using visual analogue scale, Kujala scoring questionnaire and muscle girth measurement. Data was analysed using SPSS 20. RESULTS: Of the 30 patients, 15(50%) were in each of the two groups. There were 20(66.7%) females and 10(33.3%) men with an overall mean age of 66.5}6.5 years. Also, 18(60%) subjects were overweight on the basis of body mass index. There were significant improvement in terms of pain and disability in both the groups (p<0.05)), but only Group A showed significant improvement in muscle girth (p<0.05). Overall there was no significant difference between the groups (p>0.05). CONCLUSIONS: Strengthening exercises reduced pain and disability, but the addition of blood flow restriction had no significant impact except in terms of muscle size.


Asunto(s)
Osteoartritis de la Rodilla , Estudios de Casos y Controles , Niño , Terapia por Ejercicio , Femenino , Humanos , Masculino , Fuerza Muscular , Osteoartritis de la Rodilla/terapia , Músculo Cuádriceps , Resultado del Tratamiento
20.
Medicine (Baltimore) ; 100(38): e27297, 2021 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-34559141

RESUMEN

ABSTRACT: Despite the impact of leg muscle strength on lower extremity motor performance-including walking and sit-to-stand transfer-it remains difficult to predict the relationship between bilateral leg muscle strength and lower extremity performance. Therefore, this study was designed to predict lower extremity function through the differential modeling of logarithmic and linear regression, based on knee extension strength.The study included 121 individuals living in the same community. The bilateral strengths of the knee extensors were measured using a handheld dynamometer, and the Timed Up & Go test (TUG) performance time and 5-m minimum walking times were assessed to predict lower extremity motor functions. Bilateral normalized knee extension muscle strengths and lower extremity motor function scores, including walking or TUG performance times, were assessed on the logarithmic and linear models. The Akaike information criterion (AIC) was used to evaluate the coefficient compatibility between the logarithmic regression model and the linear regression model.The AIC value for the linear model was lower than that for the logarithmic model regarding the walking time. For walking time estimation in the linear model, the coefficient value of knee extension strength was larger on the strong than on the weak side; however, the AIC value for the logarithmic model was lower than that for the linear model regarding TUG performance time. In the logarithmic model's TUG performance time estimation, the coefficient value of knee extension strength was larger on the weak than on the strong side.In conclusion, our study demonstrated different models reflecting the relationship between both legs' strengths and lower extremity performance, including the walking and TUG performance times.


Asunto(s)
Articulación de la Rodilla/fisiología , Extremidad Inferior/fisiología , Fuerza Muscular , Prueba de Paso , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Modelos Lineales , Modelos Logísticos , Masculino , Persona de Mediana Edad
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