Blanca Romero-Moraleda, Juan Del Coso, Jorge Gutiérrez-Hellín, Carlos Ruiz-Moreno, Jozo Grgic and Beatriz Lara
effects of different phases of the menstrual cycle on muscle strength and powerperformance as assessed using barbell velocity measures across low, moderate, and high loading zones. Therefore, the aim of this study was to investigate muscle performance variations across three phases of the menstrual cycle (ELP, LFP, and MLP) by measuring velocity, power and force output in the Smith machine half-squat exercise with loads equivalent to 20, 40, 60 and 80% of 1RM.
Thirteen female triathletes volunteered to participate in this study (age = 31
Esmaeil Homayoun, Hassan Ghassemi and Hamidreza Ghafari
., Extreme responses of a combined spar-type floating wind turbine and floating wave energy converter (STC) system with survival modes. Ocean Engineering, 2013. 65 : pp. 71-82.
9. Muliawan, M.J., M. Karimirad, and T. Moan, Dynamic response and powerperformance of a combined spar-type floating wind turbine and coaxial floating wave energy converter. Renewable Energy, 2013. 50 : pp. 47-57.
10. Muliawan, M.J., et al. STC (Spar-Torus Combination): a combined spar-type floating wind turbine and large point absorber floating wave energy converter—promising and
regarded as an appropriate test for evaluating powerperformance of the lower limbs, and has the benefit of being directly related to refereeing ( Tessitore et al., 2007 ). Although some researchers have observed a significant decrease in soccer players’ lower limb power as measured by the vertical jump test after a soccer match ( Nedelec et al., 2014 ), other researchers have found that athletes show higher lower limb power after fatiguing tasks ( Boullosa and Tuimil, 2009 ; Boullosa et al., 2011 ). A study of match officials concluded that soccer referees’ jumping
Felipe A. S. Lopes, Valéria L. G. Panissa, Ursula F. Julio, Elton M. Menegon and Emerson Franchini
The objective of this study was to verify the effect of active and passive recovery on blood lactate concentration and power performance. Twelve male subjects were submitted to a maximal strength test in the the bench press, a maximal aerobic test in the bench step, and to four sets of bench press exercise performed as fast and as long as possible, using 80% of maximal strength when active or passive recovery was performed. The maximum number of repetitions, mean and peak power in eccentric and concentric phases were computed and blood lactate concentration was measured. Comparisons for the variables were made using a two-way variance analysis (recovery type and set numer) with repeated measures in the second factor. When significant differences were detected (p < 0.05), a Tukey post-hoc test was used. There was a main effect of set number on maximum number of repetitions (p < 0.05) (1 > 2, 3, and 4; 2 > 3 and 4; 3 > 4). Mean and peak power in both eccentric and concentric phases also differed across sets (1 > 2, 3, and 4; 2 > 4). There was also a main effect for the recovery type, with lower values (p < 0.05) observed for the active recovery compared to the passive one. It can be concluded that active recovery resulted in lower lactate concentration, but did not improve power performance in the bench press exercise.
Hag Soo Jang, Hwa Joon Lee, Young Ryeol Joo, Jung Joong Kim and Ho Hwan Chun
The hydrodynamic effect of appendages for high-speed passenger vessels, such as Ro-Pax, Ro-Ro and cruiser vessels, is very severe and, therefore, it is essential to carry out the design of appendages for high-speed passenger vessels from the preliminary design stage to the final detail design stage through a full survey of the reference vessels together with sufficient technical investigation. Otherwise, many problems would be caused by mismatches between the appendages and the hull form. This paper investigates the design characteristics of some appendages, such as the side thruster, the shaft-strut, and the stern wedge, based on the design experience accumulated at Samsung, on CFD, and on model test results for high-speed passenger vessels. Further to this investigation, some practical and valuable design guidelines for such appendages are suggested.
Klaus Wirth, Michael Keiner, Hagen Hartmann, Andre Sander and Christoph Mickel
The aim of this study was to evaluate the effectiveness of free-weight and machine-based exercises to increase different strength and speed-strength variables. One hundred twenty male participants (age: 23.8 ± 2.5 years; body height: 181.0 ± 6.8 cm; body mass: 80.2 ± 8.9 kg) joined the study. The 2 experimental groups completed an 8 week periodized strength training program that included 2 training sessions per week. The exercises that were used in the strength training programs were the parallel barbell squat and the leg press. Before and after the training period, the 1-repetition-maximum in the barbell squat and the leg press, the squat jump, the countermovement jump and unilateral isometric force (maximal isometric force and the rate of force development) were evaluated. To compare each group pre vs. post-intervention, analysis of variance with repeated measures and Scheffé post-hoc tests were used. The leg press group increased their 1-repetition-maximum significantly (p < 0.001), while in the squat group such variables as 1-repetition-maximum, the squat jump and the countermovement jump increased significantly (p < 0.001). The maximal isometric force showed no statistically significant result for the repeated measures factor, while the rate of force development of the squat group even showed a statistically significant decrease. Differences between the 2 experimental groups were detected for the squat jump and the countermovement jump. In comparison with the leg press, the squat might be a better strength training exercise for the development of jump performance.
Irineu Loturco, Lucas A. Pereira, Ciro Winckler, Jaime R. Bragança, Roger A. da Fonseca, Ronaldo Kobal, Cesar C. Cal Abad, Katia Kitamura, Fabio Y. Nakamura and Emerson Franchini
been reported as a discriminant factor in Olympic judo ( Franchini et al., 2011 ; Zaggelidis and Lazaridis, 2012 ). Nevertheless, no study was found analyzing the development of muscle power across a competitive season in Paralympic judokas. Thus, the main objective of this study was to describe the variations in powerperformance of elite Paralympic judokas throughout a competitive training season including such important events as the ParaPan American Games, the World Championship and the Paralympic Games.
Eleven Paralympic judo
Irineu Loturco, Valmor Tricoli, Hamilton Roschel, Fabio Yuzo Nakamura, Cesar Cavinato Cal Abad, Ronaldo Kobal, Saulo Gil and Juan José González-Badillo
heavy-resistance and plyometric training. J Sei Med Sport, 2013; 16(2): 146-150
Sanchez-Medina L, Perez CE, Gonzalez-Badillo JJ. Importance of the propulsive phase in strength assessment. Int J Sports Med, 2010; 31(2): 123-129
Weiss LW, Fry AC, Wood LE, Relyea GE, Melton C. Comparative Effects of Deep Versus Shallow Squat and Leg-Press Training on Vertical Jumping Ability and Related Factors. J Strength Cond Res, 2000; 14(3): 241-247
Young WB, Jenner A, Griffiths K. Acute Enhancement of PowerPerformance From Heavy Load Squats. J Strength Cond Res, 1998
Hubert Makaruk, Tomasz Sacewicz, Adam Czaplicki and Jerzy Sadowski
Gehri DJ, Ricard MD, Kleiner DM, Kirkendall DT. A comparison of plyometric training techniques for improving vertical jump ability and energy production. J Strength Cond Res. 1998; 12:85-89.
Gollhofer A, Kyrolainen H. Neuromuscular control of the human leg extensor muscles in jump exercises under various stretch-load conditions. Int J Sports Med. 1991; 12:34-40.
Hoffman JR, Ratamess NA, Cooper JJ, Kang J, Chilakos A, Faigenbaum AD. Comparison of loaded and unloaded jump squat training on strength/powerperformance in