Muscle Architecture and Maximal Strength between Male Practitioners of Functional Fitness Training and Strength Training.

Functional Fitness Training (FFT) is a very popular training method in recent years. However, the combination of aerobic and strength components of this training method raised the hypothesis of impaired strength and muscle structure when compared to Strength Training (ST). Thus, the study aimed to compare muscle architecture and strength between FFT and ST, and the relationship between muscle architecture and maximum strength performance. Males (28.46 ± 6.03 years), nonathletes, and practitioners for two years in FFT (n = 8) and ST (n = 8), in addition to males classified as physically active (n = 8) were recruited. Muscle architecture of the rectus femoris (RF) and vastus lateralis (VL) of the thigh were evaluated with the aid of B-mode ultrasound and maximum strength in the back squat through the one-repetition maximum test. For muscle architecture, the fascicle length (FL), pennation angle (PAn), and muscle thickness (MT) were evaluated, in addition to the cross-sectional area (CSA). The FL, PAn, MT, and CSA of the RF and VL did not differ between the FFT and ST groups. Similarly, maximum strength did not differ between the FFT (152 ± 23.68 kg) and ST (151.88 ± 14.77 kg) groups. A significant relationship was observed between the PAn of the RF and the maximum strength (r =0.862; p =0.006) of FFT practitioners. The muscle architecture, CSA, and muscle strength do not differ between FFT and ST male practitioners, and PAn of the RF correlates with the maximum force for FFT practitioners.

Influence of Trunk Position during Three Lunge Exercises on Muscular Activation in Trained Women.

The present study aimed to compare the activation of the lower lumbar erector spinae, gluteus maximus, biceps femoris, and rectus femoris in two trunk positions (straight, and inclined) during three lunge exercises (static, step-forwarding, and walking) in trained young women in a randomized crossover design. Twelve women (24 ± 3 years) were selected and performed the lunge exercise with an overload of 30% of body weight in six conditions to analyze muscle activation via surface electromyography signals. Higher activation in the erector spinae (%MVIC) were observed (p < 0.05) when trunk position was inclined (straight = 20 ± 15, inclined = 40 ± 29) and during the walking lunge condition (static = 24 ± 16, forward = 26 ± 22, walking = 40 ± 33). Higher activation in the gluteus maximus was observed during step-forward and walking lunges conditions (static = 31 ± 12, forward = 54 ± 20, walking = 58 ± 30). All conditions displayed similar activations in the biceps femoris and rectus femoris (p > 0.05). Results indicate that positioning the trunk in a forward-inclined position induces greater lower lumbar erector spinae activation and dynamic lunge variations elicit greater muscular activation in the gluteus maximus than static lunges. Additionally, it seems that trunk and exercise variations do not influence the activation of tight muscles.

Acute effect of bodyweight-based strength training on blood pressure of hypertensive older adults: A randomized crossover clinical trial.

Background: Strength Training (ST) reduces the cardiovascular risk of hypertensive elderly people; however, there is a need for efficient and low-cost ST programs that aim to reduce blood pressure (BP) in elderly people with adherence and affectivity in this population. Objective: Evaluate the acute effect on BP and satisfaction with the practice of bodyweight-based strength training (BWST) in hypertensive older adults. Methods: Participants performed a BWST session and a control session (CS). The BWST consisted of six exercises, with three sets of 30 seconds. In the CS, no activity was performed. BP was measured before and at 0, 10, 20, and 30 minutes post-session. Participants' satisfaction was assessed. Results: Eleven older adults (65.8 ± 4.6 years; 7 men) participated in the study. There was an increase (p = .028) in systolic BP immediately after BWST, returning to baseline values in the intervals 10, 20, and 30 post-section. In the CS there was an increase (p = .009) 30 minutes post-session compared to 20 minutes. Between sessions, a lower systolic BP was found in BWST (-6.54 ± 3.31; p = .048) 30 minutes post-sessions. For satisfaction, 82% of participants were "totally satisfied" with BWST. Conclusion: The SBP is lower 30 minutes after BWST session than control session, and BWST promoted a pleasant affective response in hypertensive older adults.

Effects of Spatiotemporal Constraints and Age on the Interactions of Soccer Players when Competing for Ball Possession.

Although there are several descriptions of interpersonal coordination in soccer teams, little is known about how such coordination is influenced by space and time constraints. In this study, we analyzed variations in interpersonal coordination under different marking intensities and across different age groups. Marking intensity was manipulated by changing the players' game space and time of ball possession in a conditioned soccer game known as rondo. Five participants in each age category (U13, U15, U17, and U20) performed rondo tasks in four experimental conditions, in a total of 134 trials. The dependent variables considered were pass performance and eco-physical variables capturing the player-environment coupling, such as coupling of the marking between players. Our results demonstrate that in soccer: (1) markers and passers are tightly coupled; (2) the marker-passer coupling emerges from a flexible and adaptive exchange of passes; (3) the marker-passer coupling is stronger in markings of higher intensity and older age groups. Thus, the interactions between soccer players in marking can be analyzed as an emerging and self-organized process in the context of group performance.

Effect of Jump Interval Training on Kinematics of the Lower Limbs and Running Economy.

Ache-Dias, J, Pupo, JD, Dellagrana, RA, Teixeira, AS, Mochizuki, L, and Moro, ARP. Effect of jump interval training on kinematics of the lower limbs and running economy. J Strength Cond Res 32(2): 416-422, 2017-This study analyzed the effects of the addition of jump interval training (JIT) to continuous endurance training (40-minute running at 70% of peak aerobic velocity, 3 times per week for 4 weeks) on kinematic variables and running economy (RE) during submaximal constant-load running. Eighteen recreational runners, randomized into control group (CG) or experimental group (EG) performed the endurance training. In addition, the EG performed the JIT twice per week, which consisted of 4-6 bouts of continuous vertical jumping (30 seconds) with 5-minute intervals. The oxygen consumption (V[Combining Dot Above]O2) during the submaximal test (performed at 9 km·h) was similar before (EG: 38.48 ± 2.75 ml·kg·min; CG: 36.45 ± 2.70 ml·kg·min) and after training (EG: 37.42 ± 2.54 ml·kg·min; CG: 35.81 ± 3.10 ml·kg·min). No effect of training, group, or interaction (p > 0.05) was found for RE. There was no interaction or group effect for the kinematic variables (p > 0.05). Most of the kinematic variables had a training effect for both groups (support time [p ≤ 0.05]; step rate [SR; p ≤ 0.05]; and step length [SL; p ≤ 0.05]). In addition, according to the practical significance analysis (percentage chances of a better/trivial/worse effect), important effects in leg stiffness (73/25/2), vertical stiffness (73/25/2), SR (71/27/2), and SL (64/33/3) were found for the EG. No significant relationship between RE and stiffness were found for EG and CG. In conclusion, the results suggest that JIT induces important changes in the kinematics of the lower limbs of recreational runners, but the changes do not affect RE.

Power Output Prediction From Jump Height and Body Mass Does Not Appropriately Categorize or Rank Athletes.

The purposes of this study were (a) to verify the agreement of categorization and ranks based on the actual power output measured by a force plate (PPact) and the estimated power output (PPest) from jump height and body mass (BM), and (b) to verify whether the ratio standard is adequate to scale the PPact for BM. The countermovement jumps of 309 male athletes were analyzed. The athletes were first categorized into tertiles (superior, intermediate, and inferior) according to PPact and PPest. After that the athletes were ranked (highest to lowest power output) according to PPact and PPest. The PPest equation explained 81% of PPact variance (standard error of estimate = 277.4 W). The PPest (3,757.1 ± 579.8 W) displayed similar mean values compared with PPact (3,757.1 ± 642.3 W). However, the agreement between the categories generated by PPact and PPest was only moderate (k = 0.6; p < 0.01), and in the intermediate tertile, the categorization differs 38.8%. The agreement between the ranks analyzed from a Bland-Altman plot shows bias zero, but a wide limits of agreement (81 ranks; 26.2%). For the PPact scaling, the ratio standard may be considered as an adequate method for removing the BM effect, considering the lack of correlation between the scaled PPact (PPact/BM) and BM, and also the confirmation of Tanner's special circumstance. In conclusion, our findings indicate that the athlete's power output was not appropriately categorized or ranked when using PPest. Furthermore, the use of the scaled PPact is recommended to fairly compare athletes with different BMs.

Effect of jumping interval training on neuromuscular and physiological parameters: a randomized controlled study.

This study analyzed the effect of 4 weeks of jumping interval training (JIT), included in endurance training, on neuromuscular and physiological parameters. Eighteen recreational runners, randomized in control and experimental groups, performed 40 min of running at 70% of velocity at peak oxygen uptake, for 3 times per week. Additionally, the experimental group performed the JIT twice per week, which consisted of 4 to 6 bouts of continuous vertical jumps (30 s) with 5-min intervals. Three days before and after the training period, the countermovement (CMJ) and continuous jump (CJ30), isokinetic and isometric evaluation of knee extensors/flexors, progressive maximal exercise, and submaximal constant-load exercise were performed. The JIT provoked improvement in neuromuscular performance, indicated by (i) increased jump height (4.7%; effect size (ES) = 0.99) and power output (≈ 3.7%; ES ≈ 0.82) of CMJ and rate of torque development of knee extensors in isometric contraction (29.5%; ES = 1.02); (ii) anaerobic power and capacity, represented by the mean of jump height (7.4%; ES = 0.8), and peak power output (PPO) (5.6%; ES = 0.73) of the first jumps of CJ30 and the mean of jump height (10.2%, ES = 1.04) and PPO (9.5%, ES = 1.1), considering all jumps of CJ30; and (iii) aerobic power and capacity, represented by peak oxygen uptake (9.1%, ES = 1.28), velocity at peak oxygen uptake (2.7%, ES = 1.11), and velocity corresponding to the onset of blood lactate accumulation (9.7%, ES = 1.23). These results suggest that the JIT included in traditional endurance training induces moderate to large effects on neuromuscular and physiological parameters.

Reliability and validity of the 30-s continuous jump test for anaerobic fitness evaluation.

OBJECTIVES: To determine the test-retest reliability and concurrent validity of the 30-s continuous jump (CJ30) test using the Wingate test as a reference. DESIGN: Descriptive validity study. METHODS: Twenty-one male volleyball players (23.8 ± 3.8 years; 82.5 ± 9.1 kg; 185 ± 4.7 cm) were tested in three separate sessions. The first and second sessions were used to assess the reliability of the CJ30 while in the third session the Wingate test was performed. In the continuous jump test, consisting of maximal continuous jumps performed for 30s, jump height was determined by video kinematic analysis. Blood samples were collected after each test to determine lactate concentration. RESULTS: The CJ30 showed excellent test-retest reliability for the maximal jump height (ICC = 0.94), mean vertical jump height (ICC = 0.98) and fatigue index (ICC = 0.87). Peak lactate showed moderate reliability (ICC = 0.45). Large correlations were found between the mean height of the first four jumps of CJ30 and the peak power of the Wingate (r = 0.57), between the mean vertical jump height of CJ30 and the mean power of the Wingate (r = 0.70) and between the lactate peak of CJ30 and Wingate (r = 0.51). A moderate correlation of fatigue index between CJ30 and the Wingate was found (r = 0.43). CONCLUSIONS: The continuous jump is a reliable test and measures some of the same anaerobic properties as WAnT. The correlations observed in terms of anaerobic indices between the tests provide evidence that the CJ30 may adequately assess anaerobic performance level.

Validity of two methods for estimation of vertical jump height.

The objectives of this study were (a) to determine the concurrent validity of the flight time (FT) and double integration of vertical reaction force (DIF) methods in the estimation of vertical jump height with the video method (VID) as reference; (b) to verify the degree of agreement among the 3 methods; (c) to propose regression equations to predict the jump height using the FT and DIF. Twenty healthy male and female nonathlete college students participated in this study. The experiment involved positioning a contact mat (CTM) on the force platform (FP), with a video camera 3 m from the FP and perpendicular to the sagittal plane of the subject being assessed. Each participant performed 15 countermovement jumps with 60-second intervals between the trials. Significant differences were found between the jump height obtained by VID and the results with FT (p ≤ 0.01) and DIF (p ≤ 0.01), showing that the methods are not valid. Additionally, the DIF showed a greater degree of agreement with the reference method than the FT did, and both presented a systematic error. From the linear regression test was determined the prediction equations with a high degree of linearity between the methods VID vs. DIF (R = 0.988) and VID vs. FT (R = 0.979). Therefore, the prediction equations suggested may allow coaches to measure the vertical jump performance of athletes by the FT and DIF, using a CTM or an FP, which represents more practical and viable approaches in the sports field; comparisons can then be made with the results of other athletes evaluated by VID.

Força de reação do solo em diferentes segmentos corporais de judocas na realização de “ukemis” em diferentes tipos de tatames / Ground reaction force proceeding from different corporal segments of the judo athlete in accomplishment of “ukemis” in different types of tatamis

Este estudo de cunho exploratório teve como objetivo medir, avaliar e comparar as forças de reação do solo transmitidas através dos diferentes tipos de tatames ao corpo do judoca. Foram testados sete tatames, seis sintéticos e um de palha, nos quais foram realizadas 210 quedas, sendo 10 quedas em cada segmento corporal (mão, quadril e pé), executadas por dois judocas. Como instrumento de medida utilizou-se uma plataforma de força OR6-5 AMTI. Para a coleta de dados, os tatames eram colocados sobre a plataforma, no qual eram realizadas as quedas. Os sinais foram captados em mV , transformados em N e normalizados pelo peso corporal do judoca. Os resultados demonstraram que as FRS mais altas foram encontradas no segmento corporal quadril. Ao se comparar as FRS, para a mão o tatame “C” foi o que apresentou a maior média e o tatame “E” a menor; no pé o tatame “B” apresentou a maior valor e o tatame “F” a menor. Conclui-se que as forças de impacto foram diferentes entre os tatames e entre os segmentos e tão altos quanto a modalidades esportivas que exigem saltos e provocam impactos verticais.

This study of exploratory characteristic had as aim to measure, evaluating and comparing the ground reaction forces transmitted through different types of tatamis at the judo practitioner body. Seven tatamis, synthetic six and one of straw had been tested, in which 210 falls had been carried through being 10 falls in each corporal segment (hand, hip and foot), executed for two judo practitioners. A force plate OR6-5 AMTI was used as measure instrument. For the data collection, the tatamis were placed on the platform, in which were carried through the falls. The signals had been caught in mV and transformed into N and normalized by the corporal weight of judo practitioner. The results had demonstrated that the FRS highest had been found in the corporal segment hip. When comparing the FRS for the hand the tatamis “C” presented the average greater and the tatamis “E” the minor; in foot the tatamis “B” presented the biggest value and tatamis “F” the minor. One concludes that the impact forces had been different between the tatamis and between the segments and so high as the sports modalities that demand jumps and cause vertical impacts.

A influencia do arco plantar na postura e no conforto dos calçados ocupacionais / Influence of the arc plantar in position and confort of occupational footwear

Os calçados ocupacionais surgiram em epocas pre-historicas devido á necesssidade de proteger os pes. A proteçao, a adaptaçao funcional, ambiental e a forma anatomica deveriam ser alguns dos principais criterios utilizados na fabricaçao dos calçados para que os trabalhadores possam realizar suas tarefas com conforto e sem prejudicar a saude dos pés. Porem, observa-se que o comportamento biomecanico difere nos pes normais, cavos e planos, tanto estatica como dinamicamente. Neste estudo, 3 individuos do sexo feminino, cada um com um tipo de pé, foram avaliados quanto á postura e o toque de força concentrica isocinetica. O objetivo foi demonstrar que os fabricantes dos calçados devem atenter para a variaçao dos arcos plantares existentes e que esta pode biomecanicamente desencadear alteraçoes posturais conforme o calçado utilizado, podendo causar dores nos pés,joelhos, quadril e coluna.