Effects of Kinesio Taping on Tuck Jump Performance in Competitive Male Athletes.

This study aimed to measure the acute effects of kinesio taping at different stretches on tuck jump performance in active individuals. Seventy-five males (23.01±2.24 years, 178.35±8.12 cm, 72.47±6.58 kg) were randomly distributed into three groups: (1) kinesio taping without stretch, (2) kinesio taping with approximately 50% stretch, and (3) kinesio taping with approximately 75% stretch. The tuck jump performance of all participants was determined at baseline, immediately after applying kinesio taping, and 24 and 72 hours later. The participants' tuck jump performance did not improve immediately after the kinesio taping application, 24 hours, and 72 hours after the application. No significant differences were found between the kinesio taping groups at any time point (p>0.05). This study demonstrated no effects of kinesio taping on neuromuscular performance.

Acute bouts of upper and lower body static and dynamic stretching increase non-local joint range of motion.

PURPOSE: There are conflicts in the literature concerning the crossover or non-local effects of stretching. The objective of this study was to evaluate whether static (SS) and dynamic (DS) stretching of the shoulders would affect hip flexor range of motion (ROM) and performance and reciprocally whether SS and DS of the lower body would affect shoulder extension ROM and performance. METHODS: A randomized crossover study design examined the acute effects of upper and lower body SS and DS on lower and upper body performance measures, respectively. Experimental sessions included upper and lower body control tests, upper body (shoulder horizontal abduction) SS and lower body (hip abduction) SS, upper body (shoulder horizontal abduction and adduction) DS and lower body DS (hip abduction and adduction). Passive static and dynamic ROM (hip flexion, shoulder extension), leg flexor and elbow flexor maximal voluntary contraction isometric force, fatigue endurance and electromyography were measured. RESULTS: There were significant shoulder ROM increases following lower body SS (P < 0.010, ∆% = 8.2%) and DS (P < 0.019, ∆% = 9%). There was a significant hip flexor ROM (P < 0.016, ∆% = 5.2%) increase following upper body SS. There were no significant main effects or interactions for dynamic ROM or muscle force and activation variables. CONCLUSION: The lack of stretch-induced force and fatigue changes suggests that rather than a mechanical or neural drive mechanism, an enhanced stretch tolerance was likely the significant factor in the improved ROM.

Comparison Between Pre-Exhaustion and Traditional Exercise Order on Muscle Activation and Performance in Trained Men.

The purpose of this study was to measure the acute effects of pre-exhaustion vs. traditional exercise order on neuromuscular performance and sEMG in trained men. Fourteen young, healthy, resistance trained men (age: 25.5 ± 4.0 years, height: 174.9 ± 4.1 cm, and total body mass: 80.0 ± 11.1 kg) took part of this study. All tests were randomized and counterbalanced for all subjects and experimental conditions. Volunteers attended one session in the laboratory. First, they performed ten repetition maximum (10RM) tests for each exercise (bench press and triceps pushdown) separately. Secondly, they performed all three conditions at 10RM: pre-test (bench press and triceps pushdown, separately), pre-exhaustion (triceps pushdown+bench press, PE) and traditional (bench press+triceps pushdown, TR), and rested 30 minutes between conditions. Results showed that pre-test was significantly greater than PE (p = 0.031) but not different than TR, for total volume load lifted. There was a significant difference between the pre-test and the time-course of lactate measures (p = 0.07). For bench press muscle activity of the pectoralis major, the last repetition was significantly greater than the first repetition (pre-test: p = 0.006, PE: p = 0.016, and TR: p = 0.005). Also, for muscle activity of the triceps brachii, the last repetition was significantly greater than the first repetition (pre-test: p = 0.001, PE: p = 0.005, and TR: p = 0.006). For triceps pushdown, muscle activity of the triceps brachii, the last repetition was significantly greater than the first repetition (pre-test: p = 0.006, PE: p = 0.016, and TR: p = 0.005). For RPE, there were no significant differences between PE and TR (p = 0.15). Our results suggest that exercise order decreases repetitions performed, however, neuromuscular fatigue, lactate, and RPE are not impacted. The lack of difference in total volume load lifted between PE and TR might explain, at least in part, the similar metabolic and perceptual responses. Key pointsThe effects of different exercise order schemes (e.g. PE and TR) on muscle activity and strength performance indicated that similar responses were observed when comparing these schemes.Strength and conditioning coaches should consider these results when prescribing resistance training programs.The primary target (e.g. muscle group) of the training session should trained first, when fatigue level low, in order to maximize training outcomes.

Unilateral plantar flexors static-stretching effects on ipsilateral and contralateral jump measures.

The aim of this study was to evaluate the acute effects of unilateral ankle plantar flexors static-stretching (SS) on the passive range of movement (ROM) of the stretched limb, surface electromyography (sEMG) and single-leg bounce drop jump (SBDJ) performance measures of the ipsilateral stretched and contralateral non-stretched lower limbs. Seventeen young men (24 ± 5 years) performed SBDJ before and after (stretched limb: immediately post-stretch, 10 and 20 minutes and non-stretched limb: immediately post-stretch) unilateral ankle plantar flexor SS (6 sets of 45s/15s, 70-90% point of discomfort). SBDJ performance measures included jump height, impulse, time to reach peak force, contact time as well as the sEMG integral (IEMG) and pre-activation (IEMGpre-activation) of the gastrocnemius lateralis. Ankle dorsiflexion passive ROM increased in the stretched limb after the SS (pre-test: 21 ± 4° and post-test: 26.5 ± 5°, p < 0.001). Post-stretching decreases were observed with peak force (p = 0.029), IEMG (P<0.001), and IEMGpre-activation (p = 0.015) in the stretched limb; as well as impulse (p = 0.03), and jump height (p = 0.032) in the non-stretched limb. In conclusion, SS effectively increased passive ankle ROM of the stretched limb, and transiently (less than 10 minutes) decreased muscle peak force and pre-activation. The decrease of jump height and impulse for the non-stretched limb suggests a SS-induced central nervous system inhibitory effect. Key pointsWhen considering whether or not to SS prior to athletic activities, one must consider the potential positive effects of increased ankle dorsiflexion motion with the potential deleterious effects of power and muscle activity during a simple jumping task or as part of the rehabilitation process.Since decreased jump performance measures can persist for 10 minutes in the stretched leg, the timing of SS prior to performance must be taken into consideration.Athletes, fitness enthusiasts and therapists should also keep in mind that SS one limb has generalized effects upon contralateral limbs as well.

Acute effects of light emitting diodes therapy (LEDT) in muscle function during isometric exercise in patients with chronic obstructive pulmonary disease: preliminary results of a randomized controlled trial.

Patients with chronic obstructive pulmonary disease (COPD) are susceptible to early muscle fatigue. Light-emitting diodes therapy (LEDT) has been used to minimize muscle fatigue in athletes and healthy subjects. The aim of this study is to investigate the acute effects of LEDT on muscle fatigue and perception of effort in patients with COPD during isometric endurance test of the quadriceps femoris (QF). Ten patients (VEF1 50 ± 13% of predicted) underwent a single LEDT and sham application, 48 h apart, in a randomized crossover design. The LEDT and sham were applied in three localized areas of the QF (rectus femoris, vastus lateralis, and vastus medialis). Before and after exposure to LEDT and sham, the patients performed an isometric endurance test (60 % of the maximum voluntary isometric contraction), until the limit of tolerance concomitant to surface electromyography recording (median frequency as mean outcome). The slope obtained from linear regression analysis of the median frequency (MF) over endurance time was also used as an endurance index. Endurance time increased significantly after exposure to LEDT (from 26 ± 2 to 53 ± 5 s) as compared to sham (from 23 ± 3 to 30 ± 4 s) (F = 64, P = 0.0001). A greater decline in MF was observed during isometric endurance test after sham, compared to LEDT (F = 14.6, P = 0.004). The slope of the MF over time was lower post-LEDT compared to post-sham (-0.7 ± 0.3 vs. -1.5 ± 0.8; P = 0.004). The dyspnea score corrected for endurance time was lower post-LEDT (P = 0.008) but similar for fatigue both post-LEDT and post-sham. A single application of LEDT minimizes muscle fatigue and increases isometric endurance time.

Chronic Effects of Inter-Set Static Stretching on Morphofunctional Outcomes in Recreationally Resistance-Trained Male and Female.

Purpose: The purpose of this study was to compare the effects of resistance training (RT) with inter-set static stretching (IS) versus traditional RT (TRT) on morphofunctional outcomes in recreationally resistance-trained male and female. Methods: Twenty-two recreationally-trained subjects were allocated to IS group (n = 12) or TRT (n = 10) and completed eight weeks of RT. The only difference between the groups was that IS group included static stretching between sets, while the TRT rested between the sets. Ultrasound images, dynamic and isometric strength tests for the elbow flexors and elbow extensors were evaluated pre- and post-intervention period. Results: Total training volume (TTV) was greater in TRT than IS (p = .031). TRT and IS caused similar increases in maximal dynamic and isometric strength. Fascicle length of the brachialis increased following TRT (p = .033); muscle thickness and the pennation angle of the distal portion of the triceps brachii increased following IS (p = .035 and p = .007, respectively). There were no significant changes in thickness and architecture for biceps brachii in either group. There were no significant differences between groups for any muscle strength and morphology outcome. Conclusion: IS negatively affects TTV but does not affect muscle strength and architecture of recreationally resistance-trained male and female.

Manipulating Resistance Training Variables to Induce Muscle Strength and Hypertrophy: A Brief Narrative Review.

The regular practice of resistance training (RT) has been shown to induce relevant increases in both muscle strength and size. In order to maximize these adaptations, the proper manipulation of RT variables is warranted. In this sense, the aim of the present study was to review the available literature that has examined the application of the acute training variables and their influence on strength and morphological adaptations of healthy young adults. The information presented in this study may represent a relevant approach to proper training design. Therefore, strength and conditioning coaches may acquire a fundamental understanding of RT-variables and the relevance of their practical application within exercise prescription.

Isometric Exercise with Large Muscle Mass Improves Redox Balance and Blood Pressure in Hypertensive Adults.

PURPOSE: The aim of this study was to investigate the hemodynamic, oxidative stress (OS), and nitric oxide (NO) responses to a submaximal isometric exercise session (IES) involving large muscle mass. METHODS: Fourteen hypertensive (HTG: age = 35.9 ± 8.1 yr, height = 1.73 ± 0.10 m, total body mass = 78.0 ± 15.8 kg) and 10 normotensive (NTG: age = 41.1 ± 9.4 yr, height = 1.71 ± 0.12 m, total body mass = 82.3 ± 22.4 kg) participants performed two experimental sessions in the leg press and bench press: (i) control session and (ii) 8 sets × 1 min contraction at 30% maximal voluntary isometric contraction with 2-min rest interval. Blood pressure (BP) was measured at rest and during 60 min postexercise. Blood samples were collected at rest, immediately after the session, and 60 min postexercise. NO was obtained through the Griess reaction method. OS parameters were analyzed using commercial kits. A repeated-measures ANOVA with Bonferroni post hoc test was used to analyze all dependent variables. RESULTS: A significant decrease in systolic BP was observed only for HTG at 45 and 60 min postexercise (baseline vs 45 min: P = 0.03, Δ% = 4.44%; vs 60 min: P = 0.018, Δ% = 5.58%). NO increased immediately postexercise only for HTG (P = 0.008, Δ% = 16.44%). Regarding OS parameters, thiobarbituric acid reactive substances presented a significant reduction 60 min after the IES for NTG and HTG; catalase increased in both groups. CONCLUSIONS: The data showed that only 8 min of IES with a large muscle mass elicits an elevated pro-oxidant activity leading to a greater NO bioavailability, increases antioxidant reaction, and consequently reduces BP in hypertensive patients.

Effects of resistance training on consecutive and non-consecutive days on hormonal, neuromuscular and morphological responses in recreationally trained men / Efeitos do treinamento de força em dias consecutivos e não consecutivos nas respostas hormonal, neuromuscular e morfológica em homens treinados recreacionalmente

abstract The purpose of the present study was to investigate the effect of two recovery periods between consecutive and non-consecutive days in strength training sessions on hormonal, neuromuscular and morphological variables in recreationally trained men. Nineteen young men completed the study and were randomly divided into two groups: 24R, 24-hour recovery group (n = nine) and 72R, 72-hour recovery group (n = ten). The strength training program (RT) lasted six weeks with two serial routines, with a weekly frequency of four times. The saliva sample was collected once a week in the morning to determine salivary testosterone. The 1RM, jump against movement and body composition tests were performed in the pre- and post-training periods. As for salivary testosterone, there was no significant effect with respect to time and between groups. Both groups improved maximal strength in terms of intervention time in the barbell bench press and in the leg press 45º, not differing between groups and body composition showed significant interaction in time to body fat percentage ∆% = -14.6 ± 10.0 (24R) and -17.2 ± 10.9 (72R); p = 0.00, fat mass ∆% = -13, 7 ± 9.2 (24R) and -18.2 ± 13.0 (72R); p = 0.00 and fat-free mass ∆% = 3.5 ± 2.7 (24R) and 2.5 ± 2 .8 (72R), p = 0.00. The recovery periods 24 and 72 hours between sessions induced similar responses in the parameters investigated in recreationally strength-trained men.

resumo O objetivo do presente estudo foi investigar o efeito de dois períodos de recuperação entre dias consecutivos e não consecutivos em sessões de treinamento de força sobre variáveis hormonais, neuromusculares e morfológicas em homens treinados recreacionalmente. Dezenove homens jovens completaram o estudo e foram divididos aleatoriamente em dois grupos: 24R, grupo de recuperação de 24 horas (n = nove) e 72R, grupo de recuperação de 72 horas (n = dez). O programa de treinamento de força (TF) durou seis semanas com duas rotinas seriadas, com frequência semanal de quatro vezes. A amostra de saliva foi coletada uma vez por semana no período da manhã para determinação da testosterona salivar. Os testes de 1RM, salto contra movimento e composição corporal foram realizados nos períodos pré e pós-treinamento. Quanto à testosterona salivar, não houve efeito significativo em relação ao tempo e entre os grupos. Ambos os grupos melhoraram a força máxima em termos de tempo de intervenção no supino reto com barra e no leg press 45º, não diferindo entre os grupos e composição corporal apresentaram interação significativa no tempo para percentual de gordura corporal ∆% = -14,6 ± 10,0 (24R) e -17,2 ± 10,9 (72R); p = 0,00, massa gorda ∆% = -13, 7 ± 9,2 (24R) e -18,2 ± 13,0 (72R); p = 0,00 e massa isenta de gordura ∆% = 3,5 ± 2,7 (24R) e 2,5 ± 2,8 (72R), p = 0,00. Os períodos de recuperação de 24 e 72 horas entre as sessões induziram respostas semelhantes nos parâmetros investigados em homens treinados de força recreacionalmente.

Identification of muscle fatigue by tracking facial expressions.

Resistance training (RT) is performed at distinct levels of intensity from the beginning to the end of exercise sets, increasing the sensation of effort as the exercise progress to more vigorous levels, commonly leading to changes on the facial expression of RT practitioners. The objective of this study is to evaluate changes in facial expressions using the Facial Action Coding System(FACS) and the activation of facial muscles by surface electromyography(sEMG) at two different levels of effort during resistance exercise and to investigate the correlation between facial expression and exercise intensity and fatigue. Eleven healthy male participants [23±6years; 1.77±6 m; 78±10kg] performed a set of arm curl exercise at 50% and 85% 1RM until muscle fatigue. The Surface electromyography (sEMG activity was recorded simultaneously in areas of the epicranius muscle (EM) and zygomatic major muscle (ZM). Facial expression was recorded and blindly scored by five experienced examiners. Scores (0-5) were based on the level of activity of the ZM (lip corner puller-Action Unit 12-FACS) during exercise. Facial expression and sEMG data were obtained during the exercise at the first repetition and at muscle failure. The root mean square (RMS) of the sEMG amplitude of the EM was significantly increased between the first and last repetition (50%1RM:p = 0.002,d = 1.75; and 85%1RM:p = 0.002,d = 1.54). The RMS values for the ZM were significantly increased between the first and last repetition (50%1RM:p<0.001,d = 2.67; 85%1RM:p<0.001,d = 0.50). The RMS values for the ZM were also increased in 85%1RM compared to values obtained from 50%1RM (p = 0.001,d = 1.12) at the first repetition. AU12 scores and RMS values were not statistically different between 85%1RM and 50%1RM at the last repetition. Furthermore, there was a strong correlation (r = 0.61;p = 0.045) between AU12 scores and the sEMG peak for the ZM. In conclusion, changes in facial expression may be directly correlated with different resistance exercise intensities and fatigue.

The Effect of Different Resistance Training Load Schemes on Strength and Body Composition in Trained Men.

The purpose of this study was to evaluate the impact of moderate-load (10 RM) and low-load (20 RM) resistance training schemes on maximal strength and body composition. Sixteen resistance-trained men were randomly assigned to 1 of 2 groups: a moderate-load group (n = 8) or a low-load group (n = 8). The resistance training schemes consisted of 8 exercises performed 4 times per week for 6 weeks. In order to equate the number of repetitions performed by each group, the moderate load group performed 6 sets of 10 RM, while the low load group performed 3 sets of 20 RM. Between-group differences were evaluated using a 2-way ANOVA and independent t-tests. There was no difference in the weekly total load lifted (sets × reps × kg) between the 2 groups. Both groups equally improved maximal strength and measures of body composition after 6 weeks of resistance training, with no significant between-group differences detected. In conclusion, both moderate-load and low-load resistance training schemes, similar for the total load lifted, induced a similar improvement in maximal strength and body composition in resistance-trained men.

Efeito da massagem e pseudomassagem no desempenho agudo e recuperação autopercebida: um estudo controlado por placebo / Effect of massage and pseudo massage on acute performance and self-perceived recovery: a study placebo-controlled

RESUMO O objetivo deste estudo foi verificar o efeito da massagem ou pseudomassagem no desempenho do salto vertical. Quinze participantes foram submetidos aleatoriamente a três condições experimentais: massagem, pseudomassagem e repouso. A condição de massagem exigiu três saltos verticais unipodais seguidos de dois minutos de massagem manual nos músculos flexores plantares e, antes de executar outros três saltos, foi aplicada a Escala de Recuperação de Qualidade Total (TQR). As duas condições a seguir foram estruturadas com os mesmos procedimentos, no entanto, os participantes foram submetidos à pseudomassagem (simples-cego) ou a dois minutos de descanso. Os resultados não mostraram diferenças estatísticas na altura do salto entre as análises pré e pós, nem entre as condições experimentais (massagem 18,7 ± 4,1 vs. 18,2 ± 4,1; pseudomassagem 19,1 ± 4,0 vs. 18,3 ± 3,8; descanso 19,0 ± 4,0 vs. 18,7 ± 3,9 cm). Também não houve diferenças estatísticas no TQR entre as condições experimentais (massagem 16,2 ± 4,3; pseudomassagem 16,4 ± 3,9; descanso 15,9 ± 2,6 ua). Tanto a massagem quanto a pseudomassagem não afetaram o desempenho no salto vertical e na TQR.

ABSTRACT The aim of this study was to verify the effect of massage or pseudo massage on vertical jump performance. Fifteen participants were randomly subjected to three experimental conditions: massage, pseudo massage and rest. The massage condition required three unipodal vertical jumps followed by two minutes of manual massage on plantar flexor muscles and, before performing another three jumps, the Total Quality Recover Scale (TQR) was applied. The two following conditions were structured with the same procedures, although participants were submitted either at pseudo massage (single-blinded) or two minutes of rest. Results showed no statistical differences on jump height between pre and post analysis nor between experimental conditions (massage 18.7 ± 4.1 vs 18.2 ± 4.1; pseudo massage 19.1 ± 4.0 vs 8.3 ± 3.8; rest 19.0 ± 4.0 vs 18.7 ± 3.9 cm). There were also no statistical differences in the TQR results between experimental conditions (massage 16.2 ± 4.3; pseudo massage 16.4 ± 3.9; rest 15.9 ± 2.6 ua). Both massage and pseudo massage did not affect performance on vertical jump and TQR.

Muscle Activation Differs between Three Different Knee Joint-Angle Positions during a Maximal Isometric Back Squat Exercise.

The purpose of this study was to compare muscle activation of the lower limb muscles when performing a maximal isometric back squat exercise over three different positions. Fifteen young, healthy, resistance-trained men performed an isometric back squat at three knee joint angles (20°, 90°, and 140°) in a randomized, counterbalanced fashion. Surface electromyography was used to measure muscle activation of the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), semitendinosus (ST), and gluteus maximus (GM). In general, muscle activity was the highest at 90° for the three quadriceps muscles, yet differences in muscle activation between knee angles were muscle specific. Activity of the GM was significantly greater at 20° and 90° compared to 140°. The BF and ST displayed similar activation at all joint angles. In conclusion, knee position alters muscles activation of the quadriceps and gluteus maximus muscles. An isometric back squat at 90° generates the highest overall muscle activation, yet an isometric back squat at 140° generates the lowest overall muscle activation of the VL and GM only.

Sessão de treinamento de forca supervisionada aumenta a carga total levantada e as respostas subjetivas em sujeitos treinados / Supervised resistance training session increases the volume load and the subjective responses in well-trained men

RESUMO O treinamento de forca (TF) com supervisão pode afetar a carga total levantada (CTL), o número total de repetições (NTR), o tempo líquido sob tensão (TLT) e a percepção subjetiva de esforço (PSE) em indivíduos experientes em TF. O objetivo do presente estudo foi avaliar o efeito da supervisão do personal trainer na sessão de indivíduos experientes em TF. Quinze homens (20,0±2 anos; 176,0±4 cm; 79,3±4,7 kg) experientes com o TF realizaram duas sessões compostas com exercícios para o corpo todo. Na sessão sem supervisão do personal trainer (SPT) os sujeitos auto selecionaram as intensidades utilizadas nos exercícios e foram orientados à "selecionar a sobrecarga que eles tipicamente utilizam para realizar 10 repetições"; na sessão com a supervisão do personal trainer (CPT) os sujeitos auto selecionaram as intensidades utilizadas nos exercícios e foram orientados à "realizar o máximo de esforço possível". Foi observada maior CTL (P<0,001, Δ%=30), NTR (P<0,001, Δ%=29), TLT (P=0,003, Δ%=21) e PSE (P<0,001, Δ%=29) na sessão de TF. O presente estudo concluiu que as sessões com supervisão de um personal trainer afetam positivamente as variáveis do treinamento.

ABSTRACT Supervised resistance training may affect several acute variables such as volume load (VL), the maximum number of repetitions (NRM), time under tension (TUT), and rate of perceived exertion (RPE) in resistance trained-men. The present study aimed to evaluate the influence of the personal trainer's supervision on a resistance training session in resistance trained-men. Fifteen resistance-trained men (20,0±2 years; 176,0±4 cm; 79,3±4,7 kg) performed two training sessions composed of whole-body exercises. In the session without personal trainer's supervision (NPT) the subjects self-selected their loads for each exercise and were oriented to "select a load typically employed to perform 10 repetitions"; in the session with personal trainer's supervision (WPT) the subjects self-selected their loads for each exercise and were oriented to "perform maximum effort". It was observed greater VL (P<0,001, Δ%=30), NRM (P<0,001, Δ%=29), TUT (P=0,003, Δ%=21), and RPE (P<0,001, Δ%=29) in the resistance training session WPT. The present study concluded that supervised sessions positively affect resistance training variables.

The range of motion of the back squat exercise affects absolute volume load without changing the rating of perceived exertion / A amplitude de movimento no agachamento afeta o volume absoluto sem modificar a percepção de esforço

Abstract The range of motion (ROM) may affect the external maximal load during back squat (BS) exercise. The correct ROM manipulation can be useful as an exercise load manipulation strategy, changing the volume load during a resistance training session. The aim of this study was to evaluate the acute effects of ROM on relative load, absolute load and the rating of perceived exertion (RPE) during partial and full BS exercise with adjusted loads. Fifteen male individuals (age: 26.5±4.5 years; height: 173±6 cm; body mass: 80.6 ± 8.8 kg; resistance training experience 5±3 years) participated in this study. The experimental procedure was conducted in two sessions. In the first session, brief familiarization and a 10-repetition maximal test (10-RM) was performed for partial (PBS) and full BS exercise (FBS) with 30-min of rest interval. During the second session, all subjects performed 1 set of 10-RM in both conditions (partial and full ROM), and relative load, absolute load, and RPE were evaluated. A paired t-test was used to compare means. The results showed higher values for PBS when compared to FE exercise: relative load (PBS: 1.14±0.24xBW vs. FBS: 0.87±0.24xBW; P<0.001), and absolute load (PBS: 925±249 kg x FBS: 708±232 kg, P<0.001). Similar RPE was observed between conditions (PBS: 8.6±1.3 IEP x FBS: 8.5±1.0 IEP, P=0.855). It was concluded that PBS allowed higher relative load and absolute load during 10RM, without effects on RPE.

Resumo A amplitude de movimento durante o exercício agachamento pode afetar a sobrecarga imposta ao sistema neuromuscular. Desta forma, a manipulação da amplitude de movimento pode ser utilizada como estratégia de manipulação da sobrecarga do exercício, alterando o volume absoluto da sessão de treinamento bem como os ajustes agudos do sistema neuromuscular. O objetivo do presente estudo foi avaliar os efeitos agudos da amplitude de movimento na sobrecarga relativa, volume absoluto e na percepção subjetiva de esforço (PSE) durante o exercício agachamento total e parcial com sobrecargas ajustadas. Participaram do estudo 15 homens (idade: 26,5±4,5 anos; estatura: 173±6 cm; massa corporal total: 80,6±8,8 kg; e tempo de prática no treinamento de força 5±3 anos). O experimento foi conduzido em duas sessões. Na primeira sessão, foi realizada a familiarização, coleta dos dados antropométricos e determinação de 10 repetições máximas (RMs) para o exercício agachamento parcial (AP) e total (AT). Na segunda sessão, os voluntários realizaram 10-RMs no exercício AP e AT com as sobrecargas ajustadas. Então, os participantes foram orientados a reportar a PSE. Um teste t de student pareado foi utilizado para comparar as médias. Os resultados mostram maior volume relativo (AP: 1,14±0,24xMC vs. AT: 0,87±0,24xMC; P<0,001) e volume absoluto (AP: 925±249 kg vs AT: 708±232 kg, respectivamente, P<0,001) no agachamento parcial quando comparado ao total. A PSE não apresentou diferenças significantes entre amplitudes (AP: 8,6±1,3 vs AT: 8,5±1,0; P=0,855). Conclui-se que a realização do AP possibilita a produção de maior volume absoluto e não influencia a PSE.

Upper and lower limb muscles in patients with COPD: similarities in muscle efficiency but differences in fatigue resistance.

BACKGROUND: Peripheral muscle dysfunction is a common finding in patients with COPD; however, the structural adaptation and functional impairment of the upper and lower limb muscles do not seem to be homogenous. We compared muscle fatigue and recovery time between 2 representative muscles: the middle deltoid and the quadriceps femoris. METHODS: Twenty-one subjects with COPD (FEV1 46.1 ± 10.3% of predicted) underwent maximal voluntary isometric contraction and an endurance test (60% of maximal voluntary isometric contraction, to the limit of tolerance). The maximal voluntary isometric contraction test was repeated after 10 min, 30 min, 60 min, and 24 hours for both the quadriceps femoris and middle deltoid. Surface electromyography was recorded throughout the endurance test. RESULTS: Maximal voluntary isometric contraction significantly decreased only for the middle deltoid between 10 and 60 min after the endurance test. A significant increase of the root mean square and a greater decline in median frequency throughout the endurance test occurred for the middle deltoid, compared with the quadriceps femoris. When dyspnea and fatigue scores were corrected by endurance time, higher values were observed for the middle deltoid (0.07 and 0.08, respectively) in relation to the quadriceps femoris (0.02 and 0.03, respectively). CONCLUSIONS: Subjects with COPD had a higher fatigability of a representative upper limb muscle (middle deltoid) than a lower limb muscle (quadriceps femoris).

Propulsion phase of the single leg triple hop test in women with patellofemoral pain syndrome: a biomechanical study.

Asymmetry in the alignment of the lower limbs during weight-bearing activities is associated with patellofemoral pain syndrome (PFPS), caused by an increase in patellofemoral (PF) joint stress. High neuromuscular demands are placed on the lower limb during the propulsion phase of the single leg triple hop test (SLTHT), which may influence biomechanical behavior. The aim of the present cross-sectional study was to compare kinematic, kinetic and muscle activity in the trunk and lower limb during propulsion in the SLTHT using women with PFPS and pain free controls. The following measurements were made using 20 women with PFPS and 20 controls during propulsion in the SLTHT: kinematics of the trunk, pelvis, hip, and knee; kinetics of the hip, knee and ankle; and muscle activation of the gluteus maximus (GM), gluteus medius (GMed), biceps femoris (BF) and vastus lateralis (VL). Differences between groups were calculated using three separate sets of multivariate analysis of variance for kinematics, kinetics, and electromyographic data. Women with PFPS exhibited ipsilateral trunk lean; greater trunk flexion; greater contralateral pelvic drop; greater hip adduction and internal rotation; greater ankle pronation; greater internal hip abductor and ankle supinator moments; lower internal hip, knee and ankle extensor moments; and greater GM, GMed, BL, and VL muscle activity. The results of the present study are related to abnormal movement patterns in women with PFPS. We speculated that these findings constitute strategies to control a deficient dynamic alignment of the trunk and lower limb and to avoid PF pain. However, the greater BF and VL activity and the extensor pattern found for the hip, knee, and ankle of women with PFPS may contribute to increased PF stress.

Alongamento estático de alta intensidade não afeta o volume absoluto de uma sessão de treinamento de força para o peitoral maior e deltoide anterior / High intensity static-stretching protocol does not affect the absolute volume in a resistance training session for pectoralis major and anterior deltoid

O alongamento estático (AE) reduz o desempenho de atividades máximas de força e potência tais como saltos, arremessos e levantamentos. Entretanto, seus efeitos em repetições submáximas levadas até a falha concêntrica em exercícios isolados para o peitoral maior e deltoide anterior são pouco conhecidos. Portanto, o objetivo do presente estudo foi verificar o efeito agudo do AE na máxima amplitude de movimento passiva (ADMP) e no volume absoluto por exercício (VAE) e por total de séries (VAS) em uma sessão de treinamento de força para o peitoral maior (PM) e deltoide anterior (DA). A amostra foi composta por 11 homens saudáveis (idade: 24,4 ± 3,6 anos; estatura: 174,8 ± 4,4 cm; massa: 83,4 ± 9,8 kg), todos treinados em força (6 ± 3 anos) e com experiência nos exercícios (pecdeck, crossover e crucifixo com halteres). Os sujeitos se apresentaram no laboratório em três sessões. Na primeira sessão foram coletados os dados pessoais, antropométricos e foi realizado o teste de 10RM para os três exercícios (pecdeck, crossover e crucifixo com halteres), separadamente. As condições experimentais foram realizadas na segunda e terceira sessão de forma aleatória. Os sujeitos realizaram a sessão de treinamento de forca para o PM e DA com 5 séries de 10RM e intervalo de 1-min para os exercícios pecdeck, crossover e crucifixo com halteres com alongamento (COM-A) e sem alongamento passivo (SEM-A). O protocolo de alongamento foi composto por 6 séries de 45" e 15" de intervalo a 70-90% da percepção subjetiva de desconforto visando os adutores horizontais do ombro. Os resultados indicam que para a ADMP, ambas as condições (COM-A e SEM-A) apresentaram redução entre os momentos pré-sessão vs. pós-sessão (P<0,01). O volume absoluto não apresentou diferenças entre exercícios ou condições (P=0,184). Conclui-se que a o alongamento estático não influencia o volume absoluto da sessão de treinamento para o peitoral maior e deltoide anterior, entretanto aumenta a máxima amplitude de movimento passivo....(AU)

Static stretching (SS) reduces the performance of maximum strength and power activities such as jumps, throws, and lifts. However, its effects on submaximal repetitions until concentric failure in isolated exercises (for the major pectoralis and anterior deltoid) are poorly understood. Therefore, the objective of the present study was to verify the acute effect of the SS in the maximum passive range of movement (PROM) and the absolute volume per exercise (VAE) and total number of sets (VAS) in a resistance training session targeting the pectoralis major (PM) and anterior deltoid (AD). The sample consisted of 11 healthy men (age: 24.4 ± 3.6 years, height: 174.8 ± 4.4 cm, mass: 83.4 ± 9.8 kg). The subjects presented in the laboratory in three different sessions. In the first session, the personal and anthropometrical data were collected, and the 10RM test was performed for all exercises (pecdeck, crossover and dumbbell flat fly), separately. The experimental conditions were performed in the second and third sessions at random fashion. The subjects performed the resistance training session with 5 sets of 10RM and 1-min of rest interval for all exercises with SS (W-SS) and without SS (WT-SS). The SS protocol was composed of 6 sets of 45-sec and 15-sec of rest intervals at 70-90% of the subjective perception of discomfort targeting the horizontal adductors of the shoulder. The absolute volume did not show significant differences between exercises or conditions (P=0.184). It is concluded that the SS does not influence the absolute volume of the resistance training session for the PM and AD, however, the SS increases the maximum passive range of movement....(AU)

Effects of elastic wrap on muscle activity and isometric force of knee extensors / Efeitos da banda elástica na atividade muscular e na força isométrica dos extensores de joelho / Efectos de venda elástica en actividad muscular y fuerza isométrica de extensores de rodillas

ABSTRACT Introduction: The elastic knee wrap (EKW) is a device used by powerlifters, weightlifters and subjects undergoing strength training with the aim of stabilizing the knee joint and increasing the development of strength (carryover effect). Objective: To compare the effects of elastic knee wrap use on muscular activity of the vastus lateralis (VL) and on knee extension force during maximum voluntary isometric contraction (MVIC) on the knee extensor chair. Methods: The study included 18 healthy male strength trained (>1 year) subjects (age: 25.56 ± 4.84 years, total body mass: 81.83 ± 8.73 kg, height: 176 cm ± 5.17). Three five-second maximum voluntary isometric contractions (MVICs) of the knee extensors were performed with a 10-second interval between attempts, for each experimental condition: control (C), with elastic knee wrap (EKW), and with tensor (T). The performance of the knee extensors and VL muscle activity were evaluated. A repeated measures ANOVA was used to compare the dependent variables (carryover, peak force, IEMG and Impulse). Results: For carryover, the use of EKW presented a higher value (74.21%) than the control condition (p <0.001, d = 0.96) and was 79.37% higher than the tensor (p <0.001, d = 0.97). Peak force was 12.2% higher in condition C compared to EKW (p = .018, d = 0.71). For impulse, the control condition presented an increase of 8% compared to EKW use (p = .015, d = 0.62). No significant differences were observed for IEMG. Conclusion: Elastic knee wrap use increased strength production capacity during knee extension. The removal of the mechanical effect originating from carryover during MVIC reduces the strength performance of the knee extensors, but not the muscular activation of the VL. Level of Evidence I; Therapeutic studies - Investigation of treatment results.

RESUMO Introdução: A banda elástica de joelhos (BEJ) é um equipamento utilizado por powerlifters, weightlifters e sujeitos treinados em força, com o objetivo de estabilizar a articulação do joelho e aumentar o desempenho da força (efeito carry over). Objetivo: Comparar os efeitos do uso da banda elástica de joelhos na atividade muscular de vasto lateral (VL) e na força de extensores de joelhos, durante a contração voluntária máxima isométrica (CVMI) na cadeira extensora. Métodos: Participaram do estudo 18 sujeitos saudáveis (idade: 25,56 ± 4,84 anos, massa corporal total: 81,83 ± 8,73 kg, estatura: 176 ± 5,17 cm), do gênero masculino, treinados em força (> 1 ano). Foram realizadas três contrações voluntárias máximas (CVMI's de extensores de joelho, de cinco segundos por 10 segundos de intervalo entre as tentativas, para cada condição experimental: controle (C); com banda elástica de joelhos (BEJ); e com tensor (T). Foram avaliados o desempenho de extensores de joelho e a atividade muscular de VL. Uma ANOVA com medidas repetidas foi utilizada para comparar as variáveis dependentes (carry over; pico de força, IEMG e Impulso). Resultados: Para o carry over, o uso da BEJ apresentou maior valor (74,21%) quando comparada a condição controle (P<0,001, d=0,96) e 79,37% maior do que o tensor (P<0,001, d=0,97). O pico de força foi 12,2% maior na condição C comparado à BEJ (P=0,018, d=0,71). Para o impulso, a condição controle apresentou um aumento de 8% comparado ao uso da BEJ (P=0,015, d=0,62). Para a IEMG não foram observadas diferenças significantes. Conclusão: O uso da banda elástica de joelhos aumentou a capacidade de produção de força durante a extensão de joelho. A remoção do efeito mecânico proveniente do carry over, durante a CVMI, reduz o desempenho de força dos extensores de joelho, mas não a ativação muscular do VL. Nível de Evidência I; Estudos terapêuticos - Investigação dos resultados do tratamento.

RESUMEN Introducción: La venda elástica de rodillas (EKW) es un dispositivo utilizado por powerlifters, weightlifters y sujetos a entrenados en fuerza con el objetivo de estabilizar la articulación de rodilla y para aumentar el desarrollo de la fuerza (efecto carry over). Objetivo: Comparar los efectos del uso de venda elástica de rodillas en actividad muscular del vasto lateral (VL) y la fuerza de los extensores de rodilla durante la contracción máxima isométrica voluntaria (MVIC) en la silla extensora. Métodos: El estudio incluyó a 18 sujetos saludables (edad: 25,56 ± 4,84 años, masa corporal total: 81,83 ± 8,73 kg, altura: 176 cm ± 5,17), sexo masculino, entrenado en fuerza (> 1 año). Fueron realizadas tres contracciones máximas voluntarias extensoras de rodilla (MVIC), de cinco segundos por 10 segundos de intervalo entre intentos para cada condición experimental: control (C), con las vendas eláticas de rodillas (EKW), y con tensor (T). Fueron evaluados el desempeño de los extensores de rodilla y la actividad muscular de VL. Una ANOVA con medidas repetidas fue utilizada para comparar las variables dependientes (carry over, el tope de fuerza, IEMG e Impulso). Resultados: Para el carry over, el uso de EKW presentó un valor de mayor (74,21%) en comparación con la condición de control (P <0,001, d = 0,96) y 79,37% mayor que el tensor (P <0,001, d = 0,97). El tope de fuerza con fue 12% mayor en la condición C, comparado EKW (P = .018, d = 0,71). Para el impulso, la condición control presentó un aumento del 8% comparado al uso de la EKW (P = .015, d = 0,62). Para IEMG no fueron observadas diferencias significativas. Conclusión: El uso de vendas elásticas de rodillas aumentó la capacidad de producción de fuerza durante la extensión de rodilla. La remoción del efecto mecánico proveniente del carry over durante la MVIC reduce el desempeño de fuerza de los extensores de rodilla, pero no la activación muscular del VL. Nivel de Evidencia I; Estudios terapéuticos - Investigación de los resultados del tratamiento.

Effects of light-emitting diodes on muscle fatigue and exercise tolerance in patients with COPD: study protocol for a randomized controlled trial.

BACKGROUND: Light-emitting diodes (LED) have been used to minimize muscle fatigue in athletes and healthy subjects. Patients with chronic obstructive pulmonary disease (COPD) are susceptible to early muscle fatigue. OBJECTIVE: The objective of this study is to investigate the acute effects of LED on muscle function, exercise capacity and cardiorespiratory responses during isometric and dynamic exercise in patients with COPD. METHODS: This study will assess 30 patients with moderate to severe obstruction (forced expiratory volume-one second,FEV1 ≤70% predicted). Isometric and dynamic protocols will be conducted in two visits each, for a total of four visits a week apart. First, venous blood will be taken from the patients. The isometric protocol will start with the determination of the maximum voluntary isometric contraction (MIVC) to determine the workload (60% of MIVC) for the isometric endurance test (IET). Patients will be randomized to receive either the placebo or LED application (each point will be irradiated for 30 s and the energy received at each point will be 41.7 J). Immediately after finishing this procedure, the patients will carry out the IET until the limit of tolerance or until a 20% fall of strength is observed. After the test, another blood draw will be taken. In another visit (one week later), the same order of procedures will be performed, except with the opposite (LED or placebo). For the dynamic endurance test (DET), the same procedures described above will be followed, except with 75% of the maximal workload obtained from the incremental cycle ergometer test used instead of the IET. The electromyography will be recorded during the isometric and dynamic protocols. Differences in muscle function, exercise capacity and cardiorespiratory responses between the LED and placebo applications will be analyzed. The therapeutic effects of LED could minimize muscle fatigue in patients with COPD by increasing exercise tolerance. TRIAL REGISTRATION NUMBER: NCT01448564.