Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.628
Filtrar
1.
J Sports Sci ; 38(1): 100-105, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31638481

RESUMO

A common practice in resistance training is to perform sets of exercises at, or close to failure, which can alter movement dynamics. This study examined ankle, knee, hip, and lumbo-pelvis dynamics during the barbell back squat under a moderate-heavy load (80% of 1 repetition maximum (1RM)) when performed to failure. Eleven resistance trained males performed three sets to volitional failure. Sagittal plane movement dynamics at the ankle, knee, hip, and lumbo-pelvis were examined; specifically, joint moments, joint angles, joint angular velocity, and joint power. The second repetition of the first set and the final repetition of the third set were compared. Results showed that while the joint movements slowed (p < 0.05), the joint ranges of motion were not altered There were significant changes in most mean joint moments (p < 0.05), indicating altered joint loading. The knee moment decreased while the hip and lumbo-pelvis moments underwent compensatory increases. At the knee and hip, there were significant decreases (p < 0.05) in concentric power output (p < 0.05). Whilst performing multiple sets to failure altered some joint kinetics, the comparable findings in joint range ofmotion suggest that technique was not altered. Therefore, skilled individuals appear to maintain technique when performing to failure.


Assuntos
Extremidade Inferior/fisiologia , Região Lombossacral/fisiologia , Pelve/fisiologia , Treinamento de Resistência/métodos , Levantamento de Peso/fisiologia , Adulto , Tornozelo/fisiologia , Fenômenos Biomecânicos , Quadril/fisiologia , Humanos , Joelho/fisiologia , Masculino , Análise e Desempenho de Tarefas , Adulto Jovem
3.
Sports Biomech ; 19(1): 1-25, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29781788

RESUMO

The use of isometric strength testing, particularly the isometric mid-thigh pull (IMTP) has increased dramatically over the last decade. The IMTP and isometric squat (ISqT) provide one aspect of performance monitoring with variables such as peak force and rate of force development being derived from the force-time curve. The reliability of some of these variables is conflicting in the literature, and the reporting of the reliability is not standardised across the research. The majority of research only reports intraclass correlation coefficients with very few studies reporting coefficient of variation and 90% confidence intervals. Additionally, methods used to calculate variables from the force-time curve differ across studies. An aim of muscle strength testing is to provide normative values for specific sports, allowing coaches to distinguish between performance levels or evaluate the effects of training on performance. This narrative review aims to evaluate studies that have researched the reliability and/or reported normative data for both tests. Additionally, the testing protocols and the force-time curve analysis techniques utilised are discussed, concluding with practical applications for coaches on the uses and limitations of these tests. Results demonstrate that peak force is the most reliable measure and can be used to determine maximum strength capabilities.


Assuntos
Teste de Esforço/métodos , Força Muscular/fisiologia , Coxa da Perna/fisiologia , Levantamento de Peso , Fenômenos Biomecânicos , Humanos , Contração Isométrica/fisiologia , Valores de Referência , Reprodutibilidade dos Testes , Esportes/fisiologia
4.
Sports Biomech ; 19(1): 90-119, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31132028

RESUMO

As the sport of strongman is becoming increasingly popular, and such exercises are being commonly used by strength and conditioning coaches for a wide range of athletic groups, a greater understanding of the biomechanics of strongman exercises is warranted. To improve the quality of research, this systematic review summarised the research methodology used in biomechanical studies of strongman exercises and identified potential improvements to current approaches. A search of 5 databases found 10 articles adherent to the pre-defined inclusion criteria. The studies assessed 8 strongman exercises and included male participants of relatively similar body mass but varying training backgrounds. Due to the complexity of strongman exercises and the challenges in collecting advanced biomechanical data in the field, most studies used simplified measurement/analysis methods (e.g., 2D motion capture). Future strongman biomechanical studies should: assess under/un-researched strongman exercises; include a greater number of experienced and female strongman athletes; utilise more advanced (e.g., 3D motion capture and/or inertial sensor) technology so to provide a broader range and greater quality of data. Such approaches will provide strength and conditioning coaches, strongman coaches and athletes with a greater understanding of strongman exercises, thereby further improving exercise prescription, athlete performance and minimising risk of injury.


Assuntos
Projetos de Pesquisa , Treinamento de Resistência/métodos , Levantamento de Peso/fisiologia , Antropometria , Fenômenos Biomecânicos , Comportamento Competitivo/fisiologia , Humanos , Articulações/fisiologia , Cinética , Músculo Esquelético/fisiologia , Projetos de Pesquisa/normas
5.
Chin J Physiol ; 62(6): 241-244, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31793459

RESUMO

The aim of this study was to identify force-velocity and power-velocity curves in climbing activity protocols, used as dynamic resistance exercise in rats. Eighteen 45-day-old male Wistar rats (weight = 211.9 ± 5.2 g) were evaluated. After familiarization to the climbing procedure, the animals performed an incremental climbing test (load relative to 75% of the body mass at first stage, followed by 30 g increments with and 120 s recovery between climbs) to determine the maximum carrying capacity (MCC). After this, the animals climbed with different loads (without load, 10%, 20%, 30%, 40%, 50%, 75%, 90%, and 100% of MCC) with 120 s recovery between climbs. Time for each climb was recorded to calculate the mechanical power. The peak power was reached at 30% of MCC. For the force-velocity curve, an inversely proportional relation was observed between force and velocity, as expected, greater forces were expressed in lower velocities. Therefore, our results suggest that training at 30% of MCC should be encouraged aiming the target for greater power output and 90%-100% of MCC should be the load aiming for strength training in climbing activities for rats.


Assuntos
Condicionamento Físico Animal , Treinamento de Resistência , Animais , Teste de Esforço , Masculino , Força Muscular , Músculo Esquelético , Ratos , Ratos Wistar , Levantamento de Peso
6.
Int J Sports Med ; 40(13): 831-841, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31533156

RESUMO

The main purpose of this study was to compare the effects on strength and muscle power of a training program based on two different modalities of whole-body electrostimulation (WB-EMS) with respect to a resistance-training program aimed at improving dynamic strength. Twenty-two subjects participated in this study: Thirteen male (age 25.2±2.8 years; height 1.78±0.1 m; body mass 72.8±6.4 kg; body fat 11.6±2.3%) and nine female (age 28.2±3.5 years; height 1.63±0.05 m; body mass 56.8±7.6 kg; body fat 19.1±4.7%). Participants were randomly assigned to three groups that underwent three different 6-week training programs: two modalities of WB-EMS, based on different electrical parameters (experimental), and circuit training with overloads (control). Force-velocity curves were calculated for each participant before and after treatment. All groups improved their level of strength and muscle power (paired sample t-Test, p<0.01; d>1) with a similar magnitude. No significant differences were observed between groups (two-way 2×3 Anova, p>0.05) at the end of the experimentation. This study suggests that WB-EMS might be considered as a valid and faster alternative - or an important complementary procedure - to a traditional overload-based resistance-training program for the development of the DS.


Assuntos
Exercícios em Circuitos/métodos , Estimulação Elétrica/métodos , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento de Resistência/instrumentação , Adulto , Teste de Esforço/métodos , Feminino , Humanos , Extremidade Inferior/fisiologia , Masculino , Extremidade Superior/fisiologia , Levantamento de Peso , Adulto Jovem
7.
Int J Sports Med ; 40(13): 850-855, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31499564

RESUMO

The main purpose of the present study was to investigate the acute effects of different training loads on ratings of perceived exertion and discomfort and feelings of pleasure/displeasure in resistance-trained men. Twelve resistance-trained men (26.7±3.5 years, 85.1±17.5 kg, and 174. 9±9.9 cm) performed 3 sets of the bench press, squat on a hack machine, and lat pulldown, until volitional concentric failure in two separate conditions: a moderate load (MOD) consisting of a relative load of 8-12 repetitions maximum (RM), and a light load (LIT) consisting of a relative load of 25-30RM. The session rating of perceived exertion (sRPE), session rating of perceived discomfort (sRPD), and session pleasure/displeasure feelings (sPDF) were assessed after 15 min after the ending of each session. A randomized, counterbalanced, crossover study was performed with 48 h recovery afforded between sessions. Differences between conditions were observed for sRPE and sRPD, in which scores for LIT were greater than MOD (sRPE: MOD=5.5±1.0 vs. LIT=6.4±0.7; sRPD: MOD=6.7±1.7 vs. LIT=8.7±1.0). For sPDF, MOD reported feelings of pleasure (1.2), whereas the LIT presented a feeling of displeasure (-2.3). Results suggest that resistance training performed with a light load until failure induces higher degrees of effort, discomfort and displeasure compared to a moderate load.


Assuntos
Percepção/fisiologia , Esforço Físico , Prazer/fisiologia , Treinamento de Resistência/métodos , Adulto , Estudos Cross-Over , Humanos , Masculino , Levantamento de Peso/psicologia , Adulto Jovem
9.
J Sports Sci ; 37(23): 2685-2690, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31418312

RESUMO

The aim of this study was to assess the reliability and validity of the bar-mounted PUSH BandTM 2.0 to determine peak and mean velocity during the bench press exercise with a moderate (60% one repetition maximum [1RM]) and heavy (90% 1RM) load. We did this by simultaneously recording peak and mean velocity using the PUSH BandTM 2.0 and three-dimensional motion capture from participants bench pressing with 60% and 90% 1RM. We used ordinary least products regression to assess within-session reliability and whether the PUSH BandTM 2.0 could accurately predict motion capture velocity. Results showed that PUSH BandTM 2.0 and motion capture peak and mean velocity reliability was acceptable with both loads. While there was a tendency for the PUSH BandTM 2.0 to slightly overestimate peak and mean velocity, there was no fixed bias. However, mean velocity with 60 and 90% 1RM demonstrated proportional bias (differences between predicted and motion capture values increase with magnitude). Therefore, PUSH BandTM 2.0 peak velocity with 60 and 90% 1RM is valid, but mean velocity is not.


Assuntos
Treinamento de Resistência/instrumentação , Treinamento de Resistência/métodos , Levantamento de Peso/fisiologia , Adulto , Teste de Esforço/métodos , Humanos , Masculino , Força Muscular/fisiologia , Análise de Regressão , Reprodutibilidade dos Testes , Estudos de Tempo e Movimento , Adulto Jovem
10.
J Sports Sci ; 37(23): 2667-2675, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31418319

RESUMO

This study aimed to evaluate responsiveness (ability to detect change) of isometric force-time measures to neuromuscular fatigue in resistance-trained participants using two differing protocols that modified both the instructions provided to participants and the duration of the test. Both protocols were completed at two knee joint angles in the isometric squat test. Ten participants volunteered to take part in this study (age: 27.0 ± 4.5 years, strength training experience: 7.7 ± 2.6 years). Isometric peak force (ISqTpeak) and isometric explosive force (ISqTexp) test protocols were assessed at two joint angles (knee angle 100° and 125°) pre-high intensity strength training, immediately post strength training, 24-h post, 48-h post and analysed for peak and RFD performance. Participants completed eight sets of three repetitions of the back-squat exercise as the high-intensity strength training. Results showed the highest standardised response means (SRM) detected was peak force using the ISqTpeak 100, SRM -1.97 compared to an SRM of -1.31 for RFD 200 ms in the ISqTexp 125. Peak force was the most responsive variable using the ISqTpeak protocol, whereas the ISqTexp protocol was most responsive for RFD measures. Therefore, ISqTpeak and ISqTexp test protocols should not be used interchangeably to evaluate RFD variables.


Assuntos
Contração Isométrica/fisiologia , Fadiga Muscular/fisiologia , Treinamento de Resistência/métodos , Levantamento de Peso/fisiologia , Adulto , Teste de Esforço/métodos , Feminino , Humanos , Articulação do Joelho/fisiologia , Masculino , Força Muscular/fisiologia , Mialgia/etiologia , Mialgia/fisiopatologia , Treinamento de Resistência/efeitos adversos , Adulto Jovem
11.
J Sports Sci ; 37(23): 2676-2684, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31418323

RESUMO

The velocity and magnitude in which the eccentric phase of an exercise is completed directly affects performance during the concentric phase. Therefore, the purpose of this research was to investigate the effects of eccentric phase duration on concentric outcomes at 60% and 80% of one-repetition maximum (1RM) in the squat and bench press. Sixteen college-aged, resistance-trained males completed 1RM testing, established normative eccentric durations, and performed fast (0.75 times normative) and slow (2.0 times normative) metronome-controlled eccentric duration repetitions. Outcome measures assessed during the concentric phase were: average concentric velocity (ACV), peak concentric velocity (PCV), rating of perceived exertion (RPE), range of motion (ROM), and barbell path. Eccentric duration was significantly and inversely correlated with ACV at 60% (r = -0.408, p = 0.004) and 80% (r = -0.477, p = 0.001) of 1RM squat. At 60% of 1RM squat, both fast and slow eccentric conditions produced greater (p < 0.001) PCV than normative duration with fast also producing greater PCV than slow (p = 0.044). Eccentric duration had no impact on RPE, ROM, or barbell path. Our results report for the first time that resistance-trained males performing a deliberately faster eccentric phase may enhance their own squat and bench press performance.


Assuntos
Músculo Esquelético/fisiologia , Treinamento de Resistência/métodos , Levantamento de Peso/fisiologia , Fenômenos Biomecânicos , Humanos , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Adulto Jovem
12.
J Strength Cond Res ; 33(9): 2370-2380, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31460987

RESUMO

Chéry, C and Ruf, L. Reliability of the load-velocity relationship and validity of the PUSH to measure velocity in the deadlift. J Strength Cond Res 33(9): 2370-2380, 2019-This study investigated the reliability between load and mean velocity, mean propulsive velocity, peak velocity, mean power, and peak power in the deadlift. Also, we looked at the validity of an inertial sensor (PUSH) and a linear-position transducer (Tendo) to measure velocity variables. Ten strength-trained men (23.4 ± 1.3 years) were involved in three 1 repetition maximum (1RM) testing sessions, separated by at least 72 hours. The protocol used 6 different lifting intensities, comprising 20, 40, 60, 80, 90, and 100% of 1RM. Reliability of the load-velocity and load-power relationship was assessed by comparing velocity and power measurements from session 2 and 3 for each relative %1RM. The validity of tested devices was analyzed regarding to each relative intensity by comparing results from each instrument to a reference instrument (GymAware). The findings revealed that intermediate intensities (ranging from 60 to 90% of 1RM) seem to be reliable. Furthermore, extreme points of the load-velocity curve (20, 40, and 100% of 1RM) were found to be less reliable and should therefore be used with caution when implemented as part of autoregulating strategies. Tendo produced measurements that were highly correlated with GymAware and thus, constitutes a valid and cheaper alternative. By contrast, measurements from the PUSH presented a low level of precision and accuracy. Therefore, PUSH cannot be considered as a valid tool to measure velocity variables in the deadlift.


Assuntos
Treinamento de Resistência/métodos , Transdutores , Levantamento de Peso/fisiologia , Acelerometria/instrumentação , Humanos , Masculino , Conceitos Matemáticos , Força Muscular/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem
13.
J Strength Cond Res ; 33(9): 2409-2419, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31460988

RESUMO

Hughes, LJ, Banyard, HG, Dempsey, AR, and Scott, BR. Using a load-velocity relationship to predict one repetition maximum in free-weight exercise: a comparison of the different methods. J Strength Cond Res 33(9): 2409-2419, 2019-The purpose of this study was to investigate the reliability and validity of predicting 1 repetition maximum (1RM) in trained individuals using a load-velocity relationship. Twenty strength-trained men (age: 24.3 ± 2.9 years, height: 180.1 ± 5.9 cm, and body mass: 84.2 ± 10.5 kg) were recruited and visited the laboratory on 3 occasions. The load-velocity relationship was developed using the mean concentric velocity of repetitions performed at loads between 20 and 90% 1RM. Predicted 1RM was calculated using 3 different methods discussed in existing research: minimal velocity threshold 1RM (1RMMVT), load at zero velocity 1RM (1RMLD0), and force-velocity 1RM methods (1RMFV). The reliability of 1RM predictions was examined using intraclass correlation coefficient (ICC) and coefficient of variation (CV). 1RMMVT demonstrated the highest reliability (ICC = 0.92-0.96, CV = 3.6-5.0%), followed by 1RMLD0 (ICC = 0.78-0.82, CV = 8.2-8.6%) and 1RMFV (ICC = -0.28 to 0.00, CV = N/A). Both 1RMMVT and 1RMLD0 were very strongly correlated with measured 1RM (r = 0.91-0.95). The only method which was not significantly different to measured 1RM was the 1RMLD0 method. However, when analyzed on an individual basis (using Bland-Altman plots), all methods exhibited a high degree of variability. Overall, the results suggest that the 1RMMVT and 1RMLD0 predicted 1RM values could be used to monitor strength progress in trained individuals without the need for maximal testing. However, given the significant differences between 1RMMVT and measured 1RM, and the high variability associated with individual predictions performed using each method, they cannot be used interchangeably; therefore, it is recommended that predicted 1RM is not used to prescribe training loads as has been previously suggested.


Assuntos
Conceitos Matemáticos , Força Muscular , Treinamento de Resistência , Adolescente , Adulto , Teste de Esforço , Humanos , Masculino , Reprodutibilidade dos Testes , Levantamento de Peso , Adulto Jovem
14.
Hum Mov Sci ; 67: 102510, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442623

RESUMO

The purpose of this study was to explore the level of inter- and intra-individual variability in the kinematic profiles of the back squat movement among skilled weightlifters. Ten competitive weightlifters volunteered for participation in this study. Barbell velocity (VBarbell) and angular velocity of the ankle (ωAnkle), knee (ωKnee) and hip joint (ωHip) were obtained by kinematic recording of six trials at 90% of 1RM in the back squat. Inter-individual variability was assessed by analysing inter-individual differences in the velocity curves through the statistical parametric mapping method. Intra-individual variability was assessed through a correlation analysis between the barbell velocity curves of each trial for each participant. Partial least squares regression analysis, was performed to relate changes in intra-individual variability to movement and anthropometric characteristics. Significant inter- and intra-individual differences were identified in VBarbell, ωAnkle, ωKnee, and ωHip (p ≤ 0.05). Having a short trunk and thigh, and a long shin in combination with greater anterior-posterior displacement of the barbell and slower velocities during the acceleration phase increased intra-individual movement consistency over movement variability. The results of the present study clearly demonstrate that skilled weightlifters display both significant inter- and intra-individual variability in the successful execution of the back squat.


Assuntos
Movimento/fisiologia , Postura/fisiologia , Levantamento de Peso/fisiologia , Aceleração , Adulto , Análise de Variância , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Articulação do Quadril/fisiologia , Humanos , Articulação do Joelho/fisiologia , Masculino , Desempenho Psicomotor/fisiologia , Coxa da Perna/fisiologia
15.
J Strength Cond Res ; 33(11): 2981-2990, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31453944

RESUMO

Sousa, AC, Gomes, TM, Sousa, MS, Saraiva, AR, Araujo, GS, Figueiredo, T, and Novaes, JS. Static stretch performed after strength training session induces hypotensive response in trained men. J Strength Cond Res 33(11): 2981-2990, 2019-The purpose of this study was to compare the acute effect of 3 different combinations between passive static stretching exercises (SE) with resistance training (RT) on blood pressure (BP) response in normotensive trained men. Twenty-six volunteer subjects (age: 26.1 ± 5.4 years; body mass: 86.5 ± 10.5 kg; height: 1.78 ± 0.6 cm) participated in this study. After assessing 10 repetition maximum loads for the bench press, lat pulldown, shoulder press, leg press, leg extension, and leg curl, the subjects were randomly assigned on 3 experimental conditions: (a) static SE were performed before the RT session (SE + RT); (b) static SE were performed after the RT session (RT + SE); and (c) static SE were performed between the RT session (RTSE). The BP was measured for 60 minutes after the RT session. The 2-way analysis of variance for repeated measures showed no significant difference (p > 0.05) between the experimental conditions. In within comparisons, only the RT + SE experimental condition did not cause significant increases (p = 0.07) on systolic blood pressure (SBP) when compared the baseline and post-test moments (132.2 ± 10.7 vs. 141.3 ± 18.1 mm Hg). In addition, hypotensive effects were found in SBP only in the RT + SE experimental condition when compared SBP baseline (132.2 ± 10.7 mm Hg) vs. SBP30 minutes (121.7 ± 11.8 mm Hg; p = 0.04), SBP45 minutes (120.6 ± 9.8 mm Hg; p = 0.03), and SBP60 minutes (120.0 ± 7.9 mm Hg; p = 0.00). These findings suggest that performing static SE after the RT session provide an ideal combination for a postexercise hypotensive response from 30 minutes after exercise (and this change was enhanced up to 60 minutes). In conclusion, strength and conditioning professionals can prescribe static SE after RT if the goal is to reduce blood pressure after training.


Assuntos
Pressão Sanguínea , Exercícios de Alongamento Muscular/métodos , Hipotensão Pós-Exercício , Treinamento de Resistência , Levantamento de Peso , Adulto , Humanos , Masculino , Adulto Jovem
16.
J Int Soc Sports Nutr ; 16(1): 35, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31438992

RESUMO

BACKGROUND: To prepare for competition, bodybuilders employ strategies based around: energy restriction, resistance training, cardiovascular exercise, isometric "posing", and supplementation. Cohorts of professional (PRO) natural bodybuilders offer insights into how these strategies are implemented by elite competitors, and are undocumented in the scientific literature. METHODS: Forty-seven competitors (33 male (8 PRO, 25 amateur (AMA), 14 female (5 PRO, 9 AMA) participated in the study. All PROs were eligible to compete with the Drug Free Athletes Coalition (DFAC), and all AMAs were recruited from the British Natural Bodybuilding Federation (BNBF). Competitors in these organisations are subject to a polygraph and are drug tested in accordance with the World Anti-Doping Agency. We report the results of a cross-sectional study of drug free bodybuilders competing at BNBF qualifying events, and the DFAC and World Natural Bodybuilding Federation finals. Participants completed a 34-item questionnaire assessing dietary intake at three time points (start, middle and end) of competition preparation. Participants recorded their food intake over a 24-h period in grams and/or portions. Dietary intakes of PRO and AMA competitors were then compared. Repeated measures ANOVA was used to test if nutrient intake changed over time, and for associations with division. RESULTS: Male PROs reported significantly (p < 0.05) more bodybuilding experience than AMAs (PRO: 12.3 +/- 9.2, AMA: 2.4 +/- 1.4 yrs). Male PROs lost less body mass per week (PRO: 0.5 +/- 0.1, AMA: 0.7 +/- 0.2%, p < 0.05), and reported more weeks dieting (PRO: 28.1 +/- 8.1, AMA: 21.0 +/- 9.4 wks, P = 0.06). Significant differences (p < 0.05) of carbohydrate and energy were also recorded, as well as a difference (p = 0.03) in the estimated energy deficit (EED), between male PRO (2.0 +/- 5.5 kcal) and AMA (- 3.4 +/- 5.5 kcal) competitors. CONCLUSIONS: Longer diets and slower weight loss utilized by PROs likely contributed towards a lower EED compared to the AMAs. Slower weight loss may constitute an effective strategy for maintaining energy availability and muscle mass during an energy deficit. These findings require corroboration, but will interest bodybuilders and coaches.


Assuntos
Comportamento Competitivo , Dieta , Metabolismo Energético , Fenômenos Fisiológicos da Nutrição Esportiva , Levantamento de Peso/fisiologia , Perda de Peso , Adulto , Atletas , Estudos Transversais , Suplementos Nutricionais , Ingestão de Energia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nutrientes/administração & dosagem , Reino Unido
18.
Int J Sports Med ; 40(8): 528-534, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31288292

RESUMO

Weightlifting is associated with a significant risk of shoulder injury. We used the National Electronic Injury Surveillance System (NEISS) database to identify patients presenting to U.S. emergency departments between 2000 and 2017 with weightlifting-associated shoulder injuries to determine how the health burden and demographic characteristics of these patients have changed over time. Our analyses demonstrated a significant increase in the national estimate of weightlifting-associated shoulder injuries between 2000 (N=8.073; C.I. 6.309-9.836) and 2017 (N=14.612; C.I. 12.293-16.930) (p<0.001), with linear regression (R2=0.87, P<0.001) projecting 22.691 national cases by 2030. Patients were most often males (83.3%; C.I. 81.5-85.2%) between 20-29 years of age (30.5%; C.I. 28.2%-32.8%) sustaining a sprain, strain, or muscle tear (65.1%; C.I. 60.4-69.8%). Additionally, the average age of injury (34.33 years; C.I. 33.43-35.23 years) in the 2012-2017 period was significantly higher than in prior periods (p<0.001). We postulated these findings may reflect older individuals more frequently participating in resistance training than in the past, and considered that contemporary fitness trends such as CrossFit might have higher injury rates. We believe increased awareness of this burden, coupled with focus on injury prevention strategies, could yield substantial national health and cost savings.


Assuntos
Serviço Hospitalar de Emergência/estatística & dados numéricos , Lesões do Ombro/epidemiologia , Levantamento de Peso/lesões , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Mialgia/epidemiologia , Treinamento de Resistência/efeitos adversos , Entorses e Distensões/epidemiologia , Estados Unidos/epidemiologia , Adulto Jovem
19.
Forensic Sci Med Pathol ; 15(4): 616-621, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31359306

RESUMO

Even if there are well-known consequences of anabolic androgenic steroid (AAS) abuse, their full pathway of action is still being investigated. In this context, the presented case report aims to discuss and provide evidence of unusual adverse effects linked to immunodeficiency in an AAS abuser. In fact, this kind of chronic complication, even if not usually considered, may lead sudden death. In this case a 31-year-old aesthetic weightlifter, who presented to the emergency department due to an accidental fall that resulted in left thigh trauma. This subsequently developed into left thigh necrotizing myofasciitis in the following few days. Although surgery and hyperbaric therapy were carried out, the man died. An autopsy with complete biological sampling for toxicological studies was performed. This case highlights the close relationship between AAS abuse and immunodeficiency and highlights it's importance for further studies. However, it should be considered that of all the dangerous effects produced by AAS use, necrotizing fasciitis is not such an unusual consequence.


Assuntos
Anabolizantes/efeitos adversos , Fasciite Necrosante/etiologia , Hospedeiro Imunocomprometido , Miosite/etiologia , Transtornos Relacionados ao Uso de Substâncias/complicações , Acidentes por Quedas , Adulto , Anabolizantes/administração & dosagem , Fasciite Necrosante/patologia , Evolução Fatal , Humanos , Injeções Intramusculares , Masculino , Miosite/patologia , Coxa da Perna , Levantamento de Peso
20.
J Sports Sci ; 37(22): 2596-2603, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31354059

RESUMO

This study aimed to compare the goodness of fit and the reliability of different regression models for fitting the force-velocity relationship (FV) of bench press (BP) and squat (SQ). Additionally, the reliability of the position on FV of the velocity (V1RM) and the force performed with the 1RM (F1RM) was explored. Nine rugby players and 12 judokas participated in this study. The FV of BP and SQ were obtained twice by a protocol performed until the 1RM. Individual FV were fitted by linear (LM), quadratic polynomial (PM), and exponential models (EM). Adjusted coefficients of determination of LM and PM (medians higher than 0.919) were higher than for EM. The reliability was higher for LM in comparison with PM. The reliability of V1RM was not acceptable (CV% = 19 and 18% for BP and SQ). High reliability was observed for F1RM (CV% = 3 and 2% for BP and SQ) and for the ratio between F1RM and the force-axis intercept of FV (CV% = 2 and 4% for BP and SQ). The reliability of the relative values of F1RM around 92 and 87% of F0 for BP and SQ suggests the use of these values for monitoring resistance training programmes.


Assuntos
Modelos Lineares , Modelos Estatísticos , Treinamento de Resistência/métodos , Treinamento de Resistência/estatística & dados numéricos , Levantamento de Peso/fisiologia , Levantamento de Peso/estatística & dados numéricos , Adulto , Fenômenos Biomecânicos , Estudos Transversais , Feminino , Futebol Americano/fisiologia , Humanos , Masculino , Artes Marciais/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA