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Abstract The current study aimed to analyze the validity and reliability of the T-Force and Chronojump systems to measure the movement velocity in the leg press (LP) and chest press (CP) exercises in older people. Eighteen older adults (6 men and 12 women, 79.9 ± 8.5 years) performed a set of procedures over three weeks: (i) the first week was to familiarize participants with the testing procedures, (ii) the second was to perform a progressive loading test until reaching one-repetition maximum (1RM) in the LP and CP, and (iii) in the third week, participants performed three repetitions against five loads (40, 50, 60, 70, and 80% of 1RM). The mean velocity of each repetition was recorded simultaneously through the T-Force and Chronojump devices. Linear regressions (coefficient of determination [r2] and standard error of the estimate [SEE]) analyzed the inter-device validity, and Bland-Altman plots illustrated the systematic differences between devices. A mixed-effects model estimated the mean velocity differences between devices. The relative reliability was analyzed by the intra-class correlation coefficient (ICC[1,k]), while the absolute reliability was by the standard error of measurement (SEM) and the coefficient of variation (CV). The results showed that the T-Force and Chronojump presented a high association level in measuring mean velocity in the LP and CP (r 2 range: 0.96–0.99; SEE range: 0.01–0.02 m·s− 1) and low systematic bias (0.02–0.03 m·s− 1). The mean velocity values of T-Force were significantly higher than Chronojump only for 40% 1RM (p = 0.04). Excellent reliability inter-device (ICC range: 0.95–0.98; CV range: 1.7–3.2%) and intra-device (ICC range: 0.90–0.97; CV range: 3.4–6.5%) was observed. This study shows that the T-Force and Chronojump systems are valid and reliable for measuring movement velocity in the CP and LP machines when used by older adults.

ABSTRACT Background and Aims The current study aimed to compare the effects of 12 weeks of moderate versus high‐intensity water aerobics on muscle strength, body composition, lipid profile, blood pressure, and quality of life in both adults and older adults. Methods Twenty‐one women (65.19 ± 9.37 years) were randomly allocated to moderate (MIG; n = 11) or high‐intensity groups (HIG; n = 10). Both groups attended 45‐min sessions twice a week for 12 weeks. Assessments at baseline and posttraining included muscle endurance, explosive strength, body mass, body mass index, fat mass, fat‐free mass, triglycerides, total cholesterol, blood pressure, resting heart rate, general quality of life, and general health, and the physical, psychological, social relationships, and environmental domains of quality of life. Results HIG experienced greater reductions in cholesterol (ηp2 = 0.28) and fat mass (ηp2 = 0.35), and an increase in fat‐free mass (ηp2 = 0.35), compared to the MIG. The HIG also showed greater improvements in triglycerides (ηp2 = 0.24) and physical quality of life (ηp2 = 0.19) than MIG. No significant group × time interactions were found in the other variables. Nevertheless, muscular endurance and psychological quality of life were improved in both groups (p

Studies have revealed the efficacy of non-pharmacological therapeutic interventions in slowing or delaying the onset and evolution of symptoms. Among them is physical and cognitive stimulation (Ferretti, 2016; Hernandez, Coelho, Gobbi, & Stella, 2010), which, in turn, prevent motor inactivity through the practice of physical and cognitive exercises through the activation of specific neurological functions. So, the non-invasive brain activity modulation associated with the practice of physical exercises may improve elderlies' functional autonomy and cognition. The aim of this study was to assess the effect of non-invasive brain activity modulation technique, associated with the practice of physical exercises with high cognitive demand on the functional autonomy and cognitive variables of the elderly with mild cognitive impairments. The study was registered with the Brazilian Registry of Clinical Trials (UTN Number: U1111-1249-0494). One hundred and forty elderly diagnosed with MCI, aged 60 or over, of both sexes, were divided into two groups. A control group (CG, n = 68, = 74.6, and an experimental group (EG, n=70, = 71.4 ) were formed. The cognitive and functional variables of participants were measured. Non-invasive brain stimulation (NIBS) and physical exercises with high cognitive demand were used for intervention. The CG participants remained with their normal activities, which included participation in the memory workshop activities. The EG had sessions once a week, with a mix of NIBS protocol and practice exercises with high cognitive demand. Both groups got a 7-week period between the evaluations. Although we did not find significant differences in all assessed variables (figure 1), the EG group had better functional development. In our study, there was no strict control as to the intensity of motor tasks and no addition of overload in order to actually stimulate physiological mechanisms responsible for promoting gains in physical variables. The intervention promoted a reduction of dementia effects, despite the lack of statistical significance, the EG obtained more positive results when compared to the CG.

Alzheimer's disease (AD) is the most common neurodegenerative disease (Raskin et al., 2015). Noninvasive brain stimulation (NIBS) is another form of cognitive therapy that has received attention recently (Xu et al., 2019; Calomeni et al., 2017). To investigate whether a combination of Physical Exercise (PMED) and non-invasive brain stimulation (NIBS) can minimize some of the neurobiological impairments caused by Alzheimer's disease (AD). Eighty-eight older adults were divided into four groups (n=22), named GAE (AD receiving PMED plus NIBS), GCP (AD receiving PMED), GCN (AD receiving NIBS), and GCS (control. No intervention). Binaural beats are used in NIBS and PMED. BDNF and Tau proteins were determined from blood samples. Check alpha band and SMR rhythms by EEG. All surveys were blinded. Nonparametric tests with 5% significance and size effect tests were performed before and after the intervention. For GCS (p>0.05), no differences were found for all variables, and GCN and GCS showed no improvement in inhibitory control (p>0.05) or working memory (p>0.05). GCP and GAE increased executive function (p

With advancing age, some declines in health and physical fitness become expected. Considering that water aerobics is one of the aquatic activities most practised by adults and older adults, verifying its impact on the different parameters of physical fitness in these age groups is important. The main purpose of this study was to analyse the effect of 12 weeks of water aerobics on muscle strength and body composition in adults and older adults. Twenty individuals (63.95 ± 11.21 years old) performed 12 weeks of water aerobics twice a week (45 min/session). The water aerobics classes consisted of 5 minutes of warm-up (92.25 ± 8.67 bpm), 35 minutes of the main part of the class (119.22 ± 6.80 bpm), and 5 minutes of cool down (97.70 ± 7.62 bpm). The muscle strength (i.e., countermovement jump [CMJ], medicine ball throw [MBT], chair stand test [CST], forearm flexion [FF]) and body composition (i.e., fat mass [FM] and muscle mass [MM]) were evaluated before the training program and one week after the 12 weeks. After training, significant differences were observed in CST, FF, and CMJ (Table 1). Furthermore, although the differences were not significant, most of the other variables analysed showed slight improvements. Water aerobics appears to be an interesting aquatic modality when it is intended to improve the endurance strength of the upper and lower limbs and the explosive strength of the lower limbs in adults and older adults. When we desire to enhance anthropometric parameters, it seems necessary to consider the duration of the program, requiring at least 12 weeks of water aerobics.

The study aimed to compare the effects of two warm-up strategies on mechanical force production during bench press and squat resistance training sessions. Twenty-six trained male subjects (24.37±5.83years, 75.48±12.12kg, 1.74±0.07m) performed a squat or bench press resistance training session after a specific warm-up (SWU) or general warm-up followed by a specific warm-up (GSWU). The SWU included 2x6 repetitions at 32% and 64% of the maximal load (1RM), respectively. The GSWU included 10 minutes of treadmill running (70% of heart rate reserve) followed by SWU. The resistance training session consisted of 3x6 with a load of 80% 1RM. Mechanical (mean propulsive velocity, mean propulsive power and velocity loss), physiological [heart rate (HR), blood lactate concentration], and psychophysiological variables (rating of perceived exertion) were evaluated. In the bench press and squat resistance training sessions, no differences were found in the mechanical and psychophysiological variables. When performing the bench press, the GSWU caused an increased HR response after warm-up (100.00±16.93bpm vs. 110.57±9.69bpm, p=0.03; ES=0.65, moderate effect). GSWU or SWU can both be used as preparatory activities for bench press and squat resistance training performance without related restrictions. These findings may be helpful for professionals to provide appropriate warm-up strategies to maximize resistance training. Keywords: Pre-exercise, Strength, T-Force, Velocity, Physiology, Resistance Training

We analyzed the influence of exercise order using the bench press and squat as the first or second exercise of the session on velocity performance. Ten male trained individuals (20.9 ± 0.7 years) randomly performed two protocols of three sets of six repetitions at 80% of their one-repetition maximum with different exercise sequences: the bench press followed by the squat (BP + S) and the squat followed by the bench press (S + BP). A linear velocity transducer attached to the Smith machine barbell measured the mean propulsive velocity (MPV), peak velocity (PV), and time to peak velocity. Additionally, blood lactate and heart rate were measured. Regarding the bench press, differences were found in the MPV in the first (BP + S: 0.50 ± 0.07 m·s−1 vs. S + BP: 0.42 ± 0.08 m·s−1; p = 0.03, g = 0.72) and second sets (0.50 ± 0.06 m·s−1 vs. 0.42 ± 0.07 m·s−1; p = 0.03, g = 0.73), and in the PV in the second set (0.74 ± 0.09 m·s−1 vs. 0.63 ± 0.09 m·s−1; p = 0.02, g = 0.86). Regarding the squat, although the S + BP sequence tended to show higher velocities, no significant differences were found between protocols. These results showed that squatting first decreased subsequent bench press velocity performance. On the other hand, squat velocity performance was not impaired when preceded by the bench press.

We compared the effects of velocity-monitored resistance training with an intra-set velocity loss (i.e., the decrement in repetition velocity over the set) of 10 % vs. 20 % on strength-related outcomes in older adults. We randomly assigned eighteen older adults to a velocity loss group of 10 % (n = 10; 78 ± 12 years) or 20 % (n = 8; 73 ± 10 years) to perform a 10-week training program. The primary outcomes were the one-repetition maximum (1RM) and the average mean velocity against absolute loads associated with loads 0.05). Both groups improved the 1RM leg press from pre- to mid- and post-test and the MVlow and MVhigh from pre- to mid-test (p 0.05), but both increased the MVlow from pre- to mid-test (p

In cycling, drag is the force that opposes the cyclist's motion and is caused by the cyclist's and their equipment's interaction with the air. The surface area of the cyclist and their equipment, such as the bike, helmet and body postures, have a substantial impact on how much drag they encounter. This study compared the energy cost an able-bodied and shoulder amputee cyclist through numerical simulations using computer fluid dynamics. According to the hypothesis, an able-bodied cyclist may use more energy at a given speed than an able-bodied cyclist. For this study, a professional male cyclist who weighs 65 kg and is 1.72 m tall took part. The estimated energy cost was lower in an shoulder amputee in comparison to the able-bodied cyclist. Significant statistical differences and relationships were found between the cyclists for the 11 selected speeds. Altogether, this study allows to conclude that, for the same conditions, an able-bodied cyclist deliver less energy cost in comparison to a shoulder amputee.

It has been shown that training with resistance sled sprints (RSS) can improve running performance, but the effect of different RSS loads on sprint performance is unclear. This study aimed to examine this effect on running velocity, step frequency, and step length. Twenty-one collegiate track and field male athletes (20.6 ± 1.3 years) performed eight 60-m sprints with and without a resisted sled. The sled loads were individually set based on the participant's body mass (BM) and were applied in 10% increments from 20%–80% of BM. A 20-minute rest was allowed between trials. The running distance was divided into six 10-m phases. We analyzed the mean running velocity, step frequency, and step length at each phase, observing significant interactions in each. All indices decreased with increasing loads. Significant differences were observed in running speed and step frequency between all loads, except between 70%–80% of BM, and in the step length between all loads. Additionally, the maximum values for running velocity, step frequency, and length appeared in different phases according to the load. In addition to kinematics, coaches and athletes should focus on setting running distances and loads in RSS training.

AimThis study aimed to i) determine the load-velocity relationship in the seated chest press in older adults, ii) compare the magnitude of the relationship between peak and mean velocity with the relative load, and iii) analyze the differences between sexes in movement velocity for each relative load in the chest press.Material and methodsThirty-two older adults (17 women and 15 men; 79.6±7.7 years) performed a chest press progressive loading test up to the one-repetition maximum (1RM). The fastest peak and mean velocity reached with each weight were analyzed. Quadratic equations were developed for both sexes and the effectiveness of the regression model was analyzed through a residual analysis. The equations were cross-validated, considering the holdout method. The independent samples t-test analyzed i) the differences in the magnitude of the relationship between peak and mean velocity with the relative load and ii) the differences between sexes in the peak and mean velocity for each relative load.ResultsIt was possible to observe very strong quadratic load-velocity relationships in the seated chest press in women (peak velocity: r2 = 0.97, standard error of the estimate (SEE) = 4.5% 1RM; mean velocity: r2 = 0.96, SEE = 5.3% 1RM) and men (peak velocity: r2 = 0.98, SEE = 3.8% 1RM; mean velocity: r2 = 0.98, SEE = 3.8% 1RM) without differences (p>0.05) in the magnitude of the relationship between peak and mean velocity with the relative load. Furthermore, there was no overfitting in the regression models due to the high and positive correlation coefficients (r = 0.98-0.99). Finally, men presented higher (p0.05).ConclusionMeasuring repetition velocity during the seated chest press is an objective approach to estimating the relative load in older adults. Furthermore, given the velocity differences between older women and men at submaximal loads, it is recommended to use sex-specific equations to estimate and prescribe the relative loads in older adults.

Identifying the relative loads (%1RM) that maximize power output (Pmax-load) in resistance exercises can help design interventions to optimize muscle power in older adults. Moreover, examining the maximal mean power (MPmax) and peak power (PPmax) values (Watts) would allow an understanding of their differences and associations with functionality markers in older adults. Therefore, this research aimed to 1) analyze the load-mean and peak power relationships in the leg press and chest press in older adults, 2) examine the differences between mean Pmax-load (MPmax-load) and peak Pmax-load (PPmax-load) within resistance exercises, 3) identify the differences between resistance exercises in MPmax-load and PPmax-load, and 4) explore the associations between MPmax and PPmax in the leg press and chest press with functional capacity indicators. Thirty-two older adults (79.3 ± 7.3 years) performed the following tests: medicine ball throw (MBT), five-repetition sit-to-stand (STS), 10-m walking (10 W), and a progressive loading test in the leg press and chest press. Quadratic regressions analyzed 1) the load-mean and peak power relationships and identified the MPmax-load, MPmax, PPmax-load, and PPmax in both exercises, 2) the associations between MPmax and PPmax in the chest press with MBT, and 3) the associations between MPmax and PPmax in the leg press with STSpower and 10Wvelocity. In the leg press, the MPmax-load was ∼66% 1RM, and the PPmax-load was ∼62% 1RM, both for women and men (p > 0.05). In the chest press, the MPmax-load was ∼62% 1RM, and the PPmax-load was ∼56% 1RM, both for women and men (p > 0.05). There were differences between MPmax-load and PPmax-load within exercises (p < 0.01) and differences between exercises in MPmax-load and PPmax-load (p < 0.01). The MPmax and PPmax in the chest press explained ∼48% and ∼52% of the MBT-1 kg and MBT-3 kg variance, respectively. In the leg press, the MPmax and PPmax explained ∼59% of STSpower variance; however, both variables could not explain the 10Wvelocity performance (r2 ∼ 0.02). This study shows that the Pmax-load is similar between sexes, is resistance exercise-specific, and varies within exercises depending on the mechanical power variable used in older adults. Furthermore, this research demonstrates the influence of the MBT as an upper-limb power marker in older adults.

Biomechanical analysis in swimming has been widely undertaken with propulsion and add-resistance materials. This approach tried to understand how coordination and stroke mechanics were influenced by using such aids. To date, just one study aimed to understand the effect of parachute on the propulsive force at different water flows in a flume (Schnitzler, Brazier, Button, Seifert, & Chollet, 2011). Thus, the aim of the current study was to analyse the effect of using a parachute on the kinetic and kinematic variables at different swimming velocities. An international female swimmer (age: 18 years-old) was recruited to perform three all-out trials in front-crawl at different swimming velocities (0.80, 1 and 1.20 m·s-1). This was done in two different conditions: free-swimming (FS) and swimming with a parachute (SP). The swimming velocity were controlled by a visual light pacer (DigiSwim Pacing System, Digiwest, PT) and the propulsive force (PF, N), was measured with a differential pressure system (Aquanex 4.1, STR, USA) allowing retrieve PF values for the dominant (PFD) and non-dominant (PFND) upper-limbs. The Symmetry Index (SyI, %) was calculated as reported elsewhere (Robinson, Herzog, & Nigg, 1987). The stroke frequency (SF, HZ) was assessed with a chrono-frequency meter (FINIS 3x300, Finis Inc., USA) and, therefore, the stroke length (SL, m·c-1) and stroke index (SI, m2·c-1·s-1) were estimated. Swimming with the parachute required higher propulsive forces in both limbs, as the velocity increased. The SyI showed a tendency to decrease, as the velocity and propulsive force increased. It seems that when the velocity is near to the maximum (50-m best personal record), a decrease in the deficit of the force applied by both limbs is shown, representing a more comfortable swim pace to use. Only the velocity of 1.20 m·s-1 showed a SyI bellow of 10% (cut-off value), being considered as a symmetric stroke. The SL and SI were lower in the parachute condition since the additional resistance led to a greater effort and SF. The SF presented an incremental increase within the different velocities. Swimming coaches should be aware of the hypothetical significant differences in kinetic and kinematic variables when using a parachute. The lower velocities should be avoided to maintain the integrity of the force applied and to reach a more symmetric motor pattern.

This study analyzed the acute effects of heavy strength training on mechanical, hemodynamic, metabolic, and psychophysiological responses in adult males. Thirteen recreational level males (23.3 ± 1.5 years) randomly performed two heavy strength training sessions (3 sets of 8 repetitions at 80% of one repetition maximum [1RM]) using the bench press (HST-BP) or full squat (HST-FS)). The repetition velocity was recorded in both sessions. Moreover, before and after the sessions, the velocity attained against the ~1.00 m·s−1 load (V1Load) in the HST-BP, countermovement jump (CMJ) height in the HST-FS, blood pressure, heart rate, blood lactate, and psychophysiological responses (OMNI Perceived Exertion Scale for Resistance Exercise) were measured. There were differences between exercises in the number of repetitions performed in the first and third sets (both p < 0.001). However, the mechanical fatigue (V1Load vs. CMJ height) and the psychophysiological response did not differ between sessions (p > 0.05). The HST-FS caused higher blood pressure and heart rate responses than the HST-BP (p < 0.001 and p = 0.02, respectively) and greater blood lactate changes from pre-training to post-set 1 (p < 0.05). These results showed that the number of maximal repetitions performed in both sessions was lower than the target number and decreased across sets. Moreover, the HST-BP caused a higher velocity loss than the HST-FS. Finally, the HST-FS elicited higher hemodynamic and metabolic demand than the HST-BP.

As variáveis antropométricas e a força muscular têm sido apontados como fatores determinantes para o rendimento em nadadores jovens (Morais et al., 2013). No entanto, a influência de algumas destas variáveis ainda não é clara na literatura. Com o presente estudo procuramos verificar de que forma as características antropométricas (i.e. altura, massa corporal e envergadura) e a força muscular explosiva poderão influenciar o rendimento desportivo no escalão juvenil, verificando a sua relação com as provas dos 50m e 400m livres. Foram avaliados 184 nadadores (idade: 14.64±0.80 anos; altura: 1.69±0.08m; massa corporal: 58.71±7.87kg),92 do sexo feminino e 92 do sexo masculino. Registaram-se as medidas antropométricas (massa corporal, altura e envergadura) de cada nadador. Seguiu-se a avaliação da força muscular explosiva dos membros inferiores e membros superiores, através do salto horizontal a pés juntos e do lançamento da bola medicinal (3kg), respetivamente. Em dias diferentes, foram realizadas as avaliações do rendimento (tempo) e de variáveis biomecânicas (distância de ciclo, frequência gestual, índice de nado) na prova dos 50m livres e dos 400m livres. Verificou-se uma correlação linear negativa entre a altura (r = -0.64 e r = -0.60, p

Paralympic Powerlifting is a sport in which the strength of the upper limbs is assessed through bench press performance in an adapted specific bench. It is therefore essential to optimize training methods to maximize this performance. The aim of the present study was to compare force production and muscle activation involved in partial vs. full range of motion (ROM) training in Paralympic Powerlifting. Twelve male athletes of elite national level in Paralympic Powerlifting participated in the study (28.60 ± 7.60 years of age, 71.80 ± 17.90 kg of body mass). The athletes performed five sets of 5RM (repetition maximum), either with 90% of 1RM in full ROM or with a load of 130% 1RM in partial ROM. All subjects underwent both exercise conditions in consecutive weeks. Order assignment in the first week was random and counterbalanced. Fatigue index (FI), Maximum Isometric Force (MIF), Time to MIF (Time) and rate of force development (RFD) were determined by a force sensor. Muscle thickness was obtained using ultrasound images. All measures were taken pre- and post-training. Additionally, electromyographic signal (EMG) was evaluated in the last set of each exercise condition. Post-exercise fatigue was higher with full ROM as well as loss of MIF. Full ROM also induced greater. EMG showed greater activation of the Clavicular portion and Sternal portion of pectoralis major muscle and lower in the anterior portion of deltoid muscle when full ROM was performed. Muscle thickness of the pectoralis major muscle increased post-exercise. We concluded that training with partial ROM enables higher workloads with lower loss of muscle function.

The sit-to-stand test is commonly used by clinicians and researchers to analyze the functional capacity of older adults. The test consists to stand up and sit down from a chair and can be applied either in function of a predetermined number of repetitions to be completed or according to a specific time. The most common tool used by the evaluators is the chronometer, due to its low cost and ease of use. However, this tool may miss some important data throughout the test, such as the stand-up time and the total time of each repetition, as well as other kinematic and kinetic variables. Therefore, it is necessary to develop new cheap and affordable tools to capture these data with reliability. In this perspective, the development of mobile applications can be a valid and reliable alternative for the automatic calculation of different variables with sensors’ data, including acceleration, velocity, force, power, and others. Thus, in this paper, we present a dataset related to the acquisition of the accelerometer data from a commodity smartphone for the measurement of different variables during the sit-to-stand test with institutionalized older adults. Forty participants (20 men and 20 women, 78.9 ± 8.6 years old, 71.7 ± 15.0 kg, 1.57 ± 0.1 m) from five community-dwelling centers (Centro de Dia e Apoio Domiciliário de Alcongosta, Lar Nossa Senhora de Fátima, Centro Comunitário das Minas da Panasqueira, Lar da Misericórdia, and Lar da Aldeia de Joanes) from Fundão, in Portugal, volunteered to participate in the data acquisition. A mobile phone was attached to the waist of the participants to capture the data during the sit-to-stand test. Then, seated in an armless chair with the arms crossed over the chest, the participants stood up and sat down in a chair six times. The stand-up action was ordered by an acoustic signal emitted by the mobile application. All data were acquired with the mobile application, and the outcome measures were the reaction time, total time, stand-up time and movement time. This paper describes the procedures to acquire the data. These data can be reused for testing machine learning or other methods for the evaluation of neuromuscular function in older adults during the sit-to-stand test.

The purpose of this study was to examine the psychometric properties of Peabody Developmental Motor Scales II (PDMS-2-Folio and Fewell, 2000) using a Portuguese sample. The validation of the Portuguese version of the PDMS-2 was applied according to the manual, for 392 children, from two institutions, from 12 to 48 months, with an analysis of the internal consistency (α Cronbach), of test–retest reliability (ICC) and construct validity (confirmatory factor analysis). The results of the confirmatory factorial analysis (χ2 = 55.614; df = 4; p = 0.06; χ2/df =13.904; SRMR (Standardized Root Mean Square Residual) = 0.065; CFI (Comparative Fit Index) = 0.99, TLI = 0.99, RMSEA (Root Mean Square Error of Approximation) = 0.068) of two factors (Gross Motor and Fine Motor) as the original version but correlated. Most of the subtests had good internal consistency (α = 0.85) and good test–retest stability (ICC = 0.98 to 0.99). The results indicated that the Portuguese version of the PDMS-2 is adequate and valid for assessing global and fine motor skills in children aged 12 to 48 months, and can be used as a reference tool by health and education professionals to assess motor skills and, thus, allowing to detect maladjustments, deficiencies or precocity, so that children can later receive appropriate intervention.

The aim of this study was to translate and validate of the Physical Activity Enjoyment Scale (PACES), from Mullen et al. version in Portuguese athletes, invariance across genders and nature sports and swimming, as well as, external validity, through the Portuguese version of BRSQ. Athletes (n=1032; 273 nature sports, 759 swimming) with an average age of 18,95 ± 6,59 years participated in this study. Confirmatory factor analysis (maximum likelihood), multigroup analysis (measurement invariance) and correlation analysis were used for data analyzed. Results supported the suitability of the models (one factor which eight items) showing an adequate fit to the data in each sample (general:χ²=181,96, p=

Smartphone sensors have often been proposed as pervasive measurement systems to assess mobility in older adults due to their ease of use and low-cost. This study analyzes a smartphone-based application’s validity and reliability to quantify temporal variables during the single sit-to-stand test with institutionalized older adults. Forty older adults (20 women and 20 men; 78.9 ± 8.6 years) volunteered to participate in this study. All participants performed the single sit-to-stand test. Each sit-to-stand repetition was performed after an acoustic signal was emitted by the smartphone app. All data were acquired simultaneously with a smartphone and a digital video camera. The measured temporal variables were stand-up time and total time. The relative reliability and systematic bias inter-device were assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plots. In contrast, absolute reliability was assessed using the standard error of measurement and coefficient of variation (CV). Inter-device concurrent validity was assessed through correlation analysis. The absolute percent error (APE) and the accuracy were also calculated. The results showed excellent reliability (ICC = 0.92–0.97; CV = 1.85–3.03) and very strong relationships inter-devices for the stand-up time (r = 0.94) and the total time (r = 0.98). The APE was lower than 6%, and the accuracy was higher than 94%. Based on our data, the findings suggest that the smartphone application is valid and reliable to collect the stand-up time and total time during the single sit-to-stand test with older adults.

Objective: Motivation seems to be a fundamental indicator of long-term physical exercise adherence. Self-Determination Theory (SDT) argues that social environment plays a central role in the satisfaction of basic psychological needs, which might directly affect the quality of one's motivation. Individuals who appear to be more self-determined tend to persist longer at certain behaviors. Therefore, this body of work intends to analyze the relationship between motivational variables and behavioral outcomes in the exercise context, having as theoretical background the Self-Determination Theory.Methods: This systematic review was conducted through an electronic search on Web of Science, PubMed, SPORTDiscus, and PsycINFO. Data such as instruments, main predictors and results were collected from studies published between 1985 and 2018. A total of 35 empirical studies were considered for a detailed analysis.Results: Results showed the relevance of autonomy support performed by exercise professionals, as well as the major contribution that these behaviors have toward the satisfaction of basic psychological needs, besides the inherent benefits of developing more autonomous regulations. According to the literature, few studies have analyzed interpersonal thwarting behavior and the way this relates to basic psychological needs' frustration. Nether less, there seems to be a negative relationship between less self-determined regulations and exercise practice.Conclusion: Despite the existence of numerous cross-sectional studies that demonstrate positive correlations between SDT and behavioral outcomes in the exercise context, longitudinal research that analyzes all six dimensions of interpersonal behaviors and their relationship with persistence and adherence to exercise proves to be crucial. However, according to this review, interventions based on SDT appear to be fundamental when it comes to promote the maintenance of a long-term exercise practice.

De entre as técnicas não invasivas de determinação do limiar anaeróbio, o método da determinação da velocidade crítica tem merecido grande atenção, nomeadamente no âmbito da avaliação e controlo do treino em natação. Neste sentido, o objetivo do presente artigo foi efetuar uma revisão da literatura do tipo qualitativa acerca do significado do parâmetro velocidade crítica e sua aplicação à natação. Foram abordadas questões relativas à origem e definição do conceito de velocidade crítica, às metodologias de determinação mais comuns, bem como uma breve referência ao conceito de velocidade crítica anaeróbia. A velocidade crítica é sugerida como um parâmetro não invasivo de avaliação do desempenho aeróbio e de predição do limiar anaeróbio de nadadores, independentemente do nível desportivo. As principais vantagens deste indicador resultam da facilidade de aplicação e análise num elevado número de nadadores, sem a necessidade da utilização de equipamentos dispendiosos ou de recolha de sangue. Aponta-se como uma ferramenta útil no mecanismo de prescrição e controlo de cargas de treino por meio de resultados em condições experimentais ou recorrendo a tempos obtidos durante as competições. A descriminação dos valores de velocidade crítica entre nadadores com diferentes perfis metabólicos (velocistas versus fundistas) e ainda a sua aplicabilidade em regime anaeróbio são aspetos que ainda carecem de um maior entendimento.

The aim of this study was to analyze the effect of depth on the hydrodynamic drag coefficient during the passive underwater gliding after the starts and turns. The swimmer hydrodynamics performance was studied by the application of computational fluid dynamics (CFD) method. The steady-state CFD simulations were performed by the application of k - omega turbulent model and volume of fluid method to obtain two-phase flow around a three-dimensional swimmer model when gliding near water surface and at different depths from the water surface. The simulations were conducted for four different swimming pool size, each with different depth, i.e., 1.0, 1.5, 2.0 and 3.0 m for three different velocities, i.e., 1.5, 2.0 and 2.5 m/s, with swimmer gliding at different depths with intervals of 0.25 m, each starting from the water surface, respectively. The numerical results of pressure drag and total coefficients at individual average race velocities were obtained. The results showed that the drag coefficient decreased as depth increased, with a trend toward reduced fluctuation after 0.5m depth from the water surface. The selection of the appropriate depth during the gliding phase should be a main concern of swimmers and coaches.

The purpose of this study was to analyse the effect of wearing a swimsuit on swimmer's passive drag. A computational fluid dynamics analysis was carried out to determine the hydrodynamic drag of a female swimmer's model (i) wearing a standard swimsuit; (ii) wearing a last generation swimsuit and; (iii) with no swimsuit, wearing light underwear. The three-dimensional surface geometry of a female swimmer's model with different swimsuit/underwear was acquired through standard commercial laser scanner. Passive drag force and drag coefficient were computed with the swimmer in a prone position. Higher hydrodynamic drag values were determined when the swimmer was with no swimsuit in comparison with the situation when the swimmer was wearing a swimsuit. The last generation swimsuit presented lower hydrodynamic drag values, although very similar to standard swimsuit. In conclusion, wearing a swimsuit could positively influence the swimmer's hydrodynamics, especially reducing the pressure drag component.

Considering that some studies suggest that shoulder rotators muscle imbal­ances are related to joint pain and injury, and that there are no normative data for young swimmers, the aim of this study was: i) to describe the muscle balance, fatigue and isokinetic strength profile of the shoulder rotators in young swimmers; ii) to compare the results between swimmers and a group of young non-practitioners; iii) to contribute to the acquisition of normative data of unilateral ratios of shoulder rotators. We evaluated the shoulder rotators concentric strength and unilateral ratios (ratio between torque of external and internal rotators) of 60 swimmers (age: 14.55 ± 0.5 years old; body mass: 61.16 ± 7.08 kg) and 60 non-practitioners (age: 14.62 ± 0.49 years old; body mass: 60.22 ± 10.01 kg). The evaluation was performed in the sitting position (90° abduction and elbow flexion) at 60º.s-1 and 180º.s-1 angular speeds using an isokinetic dynamometer (Biodex System 3). The results of the fatigue ratios revealed no differences between the groups. Swimmers showed unilateral ratios of 73.39 ± 17.26% in the dominant limb (DL) and 77.89 ± 15,23% in the non-dominant limb (NDL) for assessments at 60º.s-1. At 180º.s-1, ratios were 74.77± 13.99% for DL and 70.11 ± 14.57% for NDL. Swimmers presented greater muscle imbalance, and differed from non-practitioners in the ability to produce power with the internal rotators, which was significantly higher in the former group.

Considerando que alguns estudos sugerem que desequilíbrios musculares dos rotadores dos ombros estão relacionados com dores e lesões na articulação e que não existem dados normativos para jovens nadadores, o objetivo deste estudo foi: i) caracterizar o equilíbrio e fadiga musculares bem como o perfil de força isocinética dos rotadores dos ombros em nadadores jovens; ii) comparar os resultados entre nadadores com jovens não praticantes; iii) contribuir para a criação de dados normativos de rácios unilaterais dos rotadores do ombro. Foi avaliada a força isocinética com ações concên­tricas dos rotadores e respectivos rácios unilaterais (quociente entre torque dos rotadores externos e internos) em 60 nadadores (idade: 14,55 ± 0,5 anos; massa corporal: 61,16 ± 7,08 kg) e 60 não praticantes (idade: 14,62 ± 0,49 anos; massa corporal: 60,22 ± 10,01 kg). Com um dinamômetro isocinético (Biodex System 3), avaliou-se na posição de sentado (90º de abdução e de flexão do cotovelo), às velocidades angulares de 60º.s-1 e 180º.s-1. Os resultados dos índices de fadiga não revelaram diferenças entre grupos. Os nadadores apresentaram rácios unilaterais entre os 73,39±17,26% no membro dominante (MD) e 77,89±15,23% no membro não dominante (MND), para avaliações efetuadas a 60º.s-1; a 180º.s-1, obtivemos resultados entre 74,77±13,99% para MD e 70,11±14,57% para MND. Os nadadores apresentaram um maior desequilíbrio muscular, sendo a capacidade de produção de força dos rotadores internos (significativamente superior nos nadadores) o que os distingue do grupo de não praticantes.

O objetivo deste estudo foi comparar as respostas da frequência cardíaca (FC), perceção subjetiva do esforço (PSE) e da concentração de lactato (LA) nas aulas de jump fit e hidro jump. A amostra foi constituída por 8 mulheres (43.5 ± 5.2 anos, 160.0 ± 4.68 cm, 58.93 ± 4.15 kg e 25.69 ± 4.40 %MG), todas elas praticantes das aulas de fit jump. O estudo envolveu três momentos de avaliação. Na primeira foram avaliadas as medidas antropométricas, FC e LA em repouso, bem como a familiarização e treino da aula do hidro jump e da Escala de BORG. No segundo e terceiro momento de avaliação foram recolhidas as variáveis durante o hidro jump e jump fit, com 48 horas de intervalo entre as avaliações. Foi realizada a estatística descritiva e a inferencial através da ANOVA one-way com o Post Hoc de Tukey para medir a FC e LA e o teste de Friedman seguido do teste de Wilcoxon para a PSE. O estudo admitiu o nível de significância de p < .05. Não houve diferenças estatisticamente significativas entre os valores médios de todas as variáveis estudadas. O jump fit produziu efeitos semelhantes nas variáveis estudadas no meio terrestre e aquático.

Os objetivos deste estudo foram: i) caracterizar o nado submáximo e máximo do ponto de vista cinemático; ii) verificar a influência das variáveis cinemáticas na prova máxima de 200 metros crawl. Nove nadadores de elite nacionais realizaram dois testes: um submáximo, descontínuo de intensidade progressiva; outro máximo, que consistiu em uma simulação de uma prova de 200 m crawl. Foram estudados os parâmetros cinemáticos gerais da mecânica da braçada, a duração de cada fase do ciclo gestual, a velocidade do centro de massa e a variação intracíclica da velocidade horizontal. Verificaram-se diferenças cinemáticas significativas da frequência gestual, velocidade de deslocamento do centro de massa, duração total do ciclo gestual, duração da ação subaquática propulsora e da velocidade do centro de massa na fase de recuperação entre os testes. Identificou-se associações significativas entre o teste máximo e algumas variáveis cinemáticas como a velocidade do centro de massa e índice de nado.The main aims of this study were i) to perform a kinematic characterization of sub and maximal swimming speed; ii) to investigate the associations between the kinematic profiles and the 200 m front crawl style. Nine national level male swimmers performed two speed tests: a submaximal discontinuous speed trial of progressive speed intensity, and a maximal one, simulating a 200 m front crawl style. The stroke general kinematic parameters, the phases duration of the stroke cycle, the velocity of the centre of mass and the intra cyclic variation of the horizontal velocity were herein studied. Significant kinematic differences in relation to stroke rate, horizontal velocity of the centre of mass, total cycle duration, absolute and relative duration of the propulsive sub aquatic action and the velocity of the centre of mass during the arms recovery were compared between the speed tests. Significant correlations between the performance in the maximal speed and some kinematic variables were observed.

The objective of this study was to develop and validate predictive equations of the cross-sectional area of the human trunk. The models were developed for males according to their level of expertise. The sample comprised 152 male subjects, all of them with a background in competitive or recreational swimming. Their ages ranged between 10 and 32 years. Two different groups of subjects were used to estimate and validate the equation. The following anthropometric characteristics were assessed: (i) body weight, (ii) height, (iii) biacromial diameter, (iv) sagittal thoracic diameter, (v) chest circumference, and (vi) cross-sectional area of the trunk. Predictive models were developed using stepwise multiple linear regression analysis. One of the models used level of expertise as a dummy variable. All models included sagittal thoracic diameter and chest circumference as independent variables (0.32 ≤ R2 ≤ 0.48; P < 0.01). The validation process of the measured and estimated cross-sectional area of the trunk did not reveal any significant differences between the mean values (P > 0.05). The simple linear regressions were moderate (0.23 ≤ R2 ≤ 0.55; 0.01 ≤ P ≤ 0.001), and the Bland-Altman criterion was met in all cases. Therefore, our findings suggest that the models developed for male swimmers according to their level of expertise are able to provide a valid prediction of the cross-sectional area of the trunk.

O objetivo do presente estudo foi comparar os efeitos do treino de força (TF) e do respectivo destreinamento entre dois modelos de periodização do volume (linear - ML; não linear - MNL) em jovens voleibolistas. A amostra foi composta por 12 jovens do sexo masculino jogadores de voleibol (17.1 ± 0.5 anos), divididos em dois grupos homogêneos. Os resultados sugerem que 8 semanas de TF induzem modificações significativas nos indicadores da força, independentemente do modelo de periodização utilizado. Contudo, o MNL parece menos eficaz no desenvolvimento da força explosiva em habilidades motoras específicas (salto vertical). Os resultados indicam que 4 semanas de destreinamento são suficientes para provocarem perdas significas na força muscular em jovens voleibolistas. O destreinamento de um ML induz a perdas significativas na força explosiva do trem superior (lançamento de bola medicinal) e inferior (salto vertical), enquanto que no MNL parece diminuir significativamente a força dinâmica máxima (supino) e o desempenho no salto vertical.This study aimed to compare the effects of strength training (ST) and detraining (DT) of two volume periodization models (linear - LM; non linear - NLM) in young male volleyball players. 12 volleyball players (17.1±0.5 years old) were randomly divided into two groups. The results of the present study suggest that 8 weeks of ST induce changes in the indicators of increased maximal strength and explosive strength, regardless of models used. However, the NLM seems less effective in the development of explosive strength in specific motor skills (vertical jump). As for DT, this study suggests that 4 weeks is sufficient to cause significant losses as an indicator of release between the two models of training. The LM induces significant losses in the explosive strength of the upper (medicine ball throwing) and lower body (vertical jump), while the NLM suggests higher losses in the maximum strength (train top) besides the jumping ability.

The purpose of this study was to develop a three-dimensional digital model of a human hand and forearm to apply Computational Fluid Dynamics to propulsion analysis in swimming. Computer tomography scans of the hand and forearm of an Olympic swimmer were applied. The data were converted, using image processing techniques, into relevant coordinate input, which could be used in Computational Fluid Dynamics software. From that analysis, it was possible to verify an almost perfect agreement between the true human segment and the digital model. This technique could be used as a means to overcome the difficulties in developing a true three-dimensional model of a specific segment of the human body. Additionally, it could be used to improve the use of Computational Fluid Dynamics generally in sports and specifically in swimming studies, decreasing the gap between the experimental and the computational data.O objetivo do presente estudo foi desenvolver um modelo digital tridimensional de uma mão e um antebraço humano para aplicar a Dinâmica Computacional de Fluidos ao estudo da propulsão em natação. Foram aplicados procedimentos computorizados de tomografia axial na mão e antebraço de um nadador Olímpico. Através de técnicas de processamento de imagem, os dados foram convertidos em coordenadas tridimensionais, que podem ser utilizadas em programas de simulação computacional. Através dos resultados encontrados, foi possível verificar uma semelhança quase perfeita entre o segmento humano e o modelo digital. Esta técnica pode ser utilizada como uma forma de ultrapassar as dificuldades em desenvolver um modelo digital tridimensional de um segmento específico do corpo humano. Complementarmente, pode ser bastante útil na melhoria da utilização da Dinâmica Computacional de Fluidos no Desporto, de uma forma geral, e, mais especificamente, nos estudos em natação, diminuindo a diferença entre a investigação experimental e a investigação computacional.

The present research aims to systematically review the determinants and reasons for swimming dropout. The systematic review was conducted through electronic searches on the Web of Knowledge and PsycInfo databases from 2 February to 29 July 2015, using the keywords dropout, withdrawal, motives, reasons, sport, framework-theories, motivation, swim*, review, attrition and compliance. Fifteen studies were found and six were fully reviewed and its data extracted and analysed. Most studies were undertaken in Canada and in the United States of America (USA), and one study was conducted in Spain. Most participants were female (65.74%), and the main reasons for dropout were ‘conflicts with their trainers’, ‘other things to do’, ‘competence improvements’ failure’, ‘parents, couples or trainers’ pressure’, ‘lack of enjoyment’ and ‘get bored’. This review contributes to the present knowledge on the understanding of dropout in swimming. However, it is necessary to continue researching on this topic, validating measurement instruments and studying the motivational processes related to dropout and persistence.

Resisted sled sprint (RSS) is a traditional sprint training in which a variety of loads are used for multiple aims. Nevertheless, a detailed analysis of the effects of different loads has not yet been performed. Therefore, this study aimed to examine the effects of load differences on running velocity, step frequency, and step length during RSS in trained collegiate track and field athletes. Twenty-one collegiate track and field male athletes (20.6±1.3 years) performed eight 60-m sprints with and without a resisted sled. The sled loads were individually set based on the participant's body mass (BM) and were applied in 10% increments from 20% to 80% of BM. The running distance was divided into six 10-m phases. The mean running velocity, step frequency and step length at each phase, and interactions in each were analysed. All indices decreased with increasing loads. Significant differences were observed in running velocity and step frequency between all loads, except between 70% and 80% of BM, and in the step length between all loads. The maximum values for the variables appeared in different phases according to the load. These results suggested that athletes and coaches should consider that sprinting performance during RSS varies with load. [ABSTRACT FROM AUTHOR]