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1.
J Strength Cond Res ; 36(7): 1866-1874, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35446282

RESUMEN

ABSTRACT: Thomas, K, Spyridon, M, Nikolaos, Z, Angeliki-Nikolleta, S, Giorgos, K, Giorgos, G, and Gerasimos, T. Effects of complex vs. compound training on competitive throwing performance. J Strength Cond Res 36(7): 1866-1874, 2022-The purpose of this study was to investigate the effects of complex (CPX; strength and power exercises in pairs) vs. compound (CPD; strength and power exercises in different days) training on competitive track and field throwing performance. Ten well-trained throwers (7 male throwers and 3 female throwers) followed a 34-week periodized training program including 2 preparation periods. During the winter 4-week, precompetition phase, athletes were randomly assigned to CPX or CPD groups, while the opposite assignment was performed during the spring precompetition phase (counterbalanced design). Before and after each training period competitive track and field throwing performance, shot put throws, snatch, squat and bench press 1 repetition maximum (1RM), vertical jumps, rate of force development (RFD), and body composition were evaluated. Competitive track and field throwing performance increased significantly by 5.4 ± 2.9% and 1.9 ± 1.7%, after CPX and CPD, respectively, with a significant difference between groups (p < 0.001). Shot put throws and 1RM strength in bench press increased similarly after both programs (p < 0.05), but vertical jumps increased only after CPX training. CPX induced greater increases in 1RM strength in snatch and squat, RFD, and lean body mass compared with CPD (p < 0.005). The linear combination of training-induced changes in RFD 150ms, 1RM in squat, snatch, and total lean mass explained the 80% of the percentage increase in competitive track and field throwing performance (p = 0.007). These results suggest that 4 weeks of CPX training during the precompetition period induce greater increases in competitive track and field throwing performance, 1RM strength, power, and RFD compared with CPD training.


Asunto(s)
Rendimiento Atlético , Entrenamiento de Fuerza , Atletismo , Atletas , Femenino , Humanos , Masculino , ATPasas de Translocación de Protón Mitocondriales , Fuerza Muscular , Músculo Esquelético , Entrenamiento de Fuerza/métodos
2.
J Strength Cond Res ; 31(2): 359-364, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28125544

RESUMEN

Karampatsos, GP, Korfiatis, PG, Zaras, ND, Georgiadis, GV, and Terzis, GD. Acute effect of countermovement jumping on throwing performance in track and field athletes during competition. J Strength Cond Res 32(1): 359-364, 2017-The purpose of the study was to investigate whether performing 3 consecutive countermovement jumps (CMJs) just before an attempt enhances performance in track and field throwers during competition. Twelve shot putters, 8 hammer throwers, 9 discus throwers, and 3 javelin throwers of both sexes participated in the study. They performed 3 maximal CMJs 85 ± 12 seconds before the second, fourth, and sixth attempt during 3 different official competitions of national level. Maximal strength (1 repetition maximum [1RM]) in squat and bench press was measured 1 week after the competition. Mean throwing performance was significantly higher after the CMJs intervention (2.66 ± 4.3%, range of increase 0.02-18.98%, p = 0.0001). Similarly, maximum throwing performance was significantly higher after the CMJs (2.76 ± 3.29%, range of increase 0.09-13.93%, p = 0.0009). All but 2 athletes increased their best performance after the CMJs. The percentage increase in performance was similar between sexes (male athletes 2.56 ± 3.01%; female athletes 3.06 ± 3.76%, p = 0.677), but it was higher for the "lighter throws" (discus and javelin throw: 4.66 ± 4.11%) compared with the "heavier throws" (shot and hammer throw: 1.62 ± 2.04%, p = 0.008). The percentage increase in performance was not significantly correlated with 1RM squat or bench press, anthropometric characteristics, and personal best performance. These results suggest that performing 3 CMJs approximately 1 minute before an attempt may increase track and field throwing performance during competition.


Asunto(s)
Atletas , Rendimiento Atlético/fisiología , Atletismo/fisiología , Adulto , Ejercicio Físico , Femenino , Humanos , Masculino , Fuerza Muscular , Músculo Esquelético , Factores Sexuales , Adulto Joven
3.
J Strength Cond Res ; 30(1): 81-92, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26049793

RESUMEN

The rate of force development (RFD) is an essential component for performance in explosive activities, although it has been proposed that muscle architectural characteristics might be linked with RFD and power performance. The purpose of the study was to investigate the relationship between RFD, muscle architecture, and performance in young track and field throwers. Twelve young track and field throwers completed 10 weeks of periodized training. Before (T1) and after (T2) training performance was evaluated in competitive track and field throws, commonly used shot put tests, isometric leg press RFD, 1 repetition maximum (1RM) strength as well as vastus lateralis architecture and body composition. Performance in competitive track and field throwing and the shot put test from the power position increased by 6.76 ± 4.31% (p < 0.001) and 3.58 ± 4.97% (p = 0.019), respectively. Rate of force development and 1RM strength also increased (p ≤ 0.05). Vastus lateralis thickness and fascicle length increased by 5.95 ± 7.13% (p = 0.012) and 13.41 ± 16.15% (p = 0.016), respectively. Significant correlations were found at T1 and T2, between performance in the shot put tests and both RFD and fascicle length (p ≤ 0.05). Close correlations were found between RFD, muscle thickness, and fascicle length (p ≤ 0.05). Significant correlations were found between the % changes in lean body mass and the % increases in RFD. When calculated together, the % increase in muscle thickness and RFD could predict the % increase in shot put throw test from the power position (p = 0.019). These results suggest that leg press RFD may predict performance in shot put tests that are commonly used by track and field throwers.


Asunto(s)
Rendimiento Atlético/fisiología , Músculo Cuádriceps/anatomía & histología , Músculo Cuádriceps/fisiología , Atletismo/fisiología , Adolescente , Adulto , Composición Corporal , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Tamaño de los Órganos , Acondicionamiento Físico Humano/fisiología , Adulto Joven
4.
J Strength Cond Res ; 30(3): 807-17, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26907845

RESUMEN

The aim of the study was to examine the correlation between muscle morphology and jumping, sprinting, and throwing performance in participants with different power training duration experience. Thirty-six power-trained young men were assigned to 3 groups according to the length of their power training: less experienced (<1 year), moderately experienced (1-3 years), and experienced (4-7 years). All participants performed countermovement and squat jumps, 60-m sprint, and shot throws twice. Lean body mass (LBM) was evaluated with dual-energy x-ray absorptiometry and thigh muscle cross-sectional area (CSA) with anthropometry. The vastus lateralis architecture and fiber type composition were evaluated with ultrasonography and muscle biopsies, respectively. When all subjects were considered as 1 group (n = 36), jumping performance was correlated with LBM, fascicle length, and type II fiber CSA; sprinting performance was correlated with estimated thigh muscle CSA alone; and shot throwing was correlated with LBM and type I, IIA fiber CSA. In the least experienced group, the LBM of the lower extremities was the most significant contributor for power performance, whereas in the moderately experienced group, the LBM, architectural properties, and type II fiber percentage CSA were the most significant contributors. For the experienced group, fascicle length and type II fiber percentage CSA were the most significant factors for power performance. These data suggest that jumping performance is linked with muscle morphology, regardless of strength or power training. The vastus lateralis muscle morphology could only partially explain throwing performance, whereas it cannot predict sprinting performance. Power performance in experienced participants rely more on the quality of the muscle tissue rather than the quantity.


Asunto(s)
Rendimiento Atlético/fisiología , Ejercicio Físico/fisiología , Fibras Musculares de Contracción Rápida/citología , Músculo Cuádriceps/anatomía & histología , Entrenamiento de Fuerza , Absorciometría de Fotón , Adolescente , Adulto , Composición Corporal , Prueba de Esfuerzo , Humanos , Masculino , Fibras Musculares de Contracción Rápida/diagnóstico por imagen , Músculo Cuádriceps/diagnóstico por imagen , Músculo Cuádriceps/fisiología , Carrera/fisiología , Factores de Tiempo , Ultrasonografía , Adulto Joven
5.
J Strength Cond Res ; 29(9): 2559-69, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25719913

RESUMEN

The aim of the study was to compare the effects of compound vs. complex resistance training on strength, high-speed movement performance, and muscle composition. Eighteen young men completed compound (strength and power sessions on alternate days) or complex training (strength and power sets within a single session) 3 times per week for 6 weeks using bench press, leg press, Smith machine box squat, and jumping exercises. Pre- and posttraining, jumping and throwing performance and maximum bench press, leg press, and Smith machine box squat strength were evaluated. The architecture of vastus lateralis and gastrocnemius muscle was assessed using ultrasound imaging. Vastus lateralis morphology was assessed from muscle biopsies. Jumping (4 ± 3%) and throwing (9 ± 8%) performance increased only with compound training (p < 0.02). Bench press (5 vs. 18%), leg press (17 vs. 28%), and Smith machine box squat (27 vs. 35%) strength increased after both compound and complex training. Vastus lateralis thickness and fascicle angle and gastrocnemius fascicle angle were increased with both compound and complex training. Gastrocnemius fascicle length decreased only after complex training (-11.8 ± 9.4%, p = 0.006). Muscle fiber cross-sectional areas increased only after complex training (p ≤ 0.05). Fiber type composition was not affected by either intervention. These results suggest that short-term strength and power training on alternate days is more effective for enhancing lower-limb and whole-body power, whereas training on the same day may induce greater increases in strength and fiber hypertrophy.


Asunto(s)
Adaptación Fisiológica , Fuerza Muscular/fisiología , Músculo Esquelético/anatomía & histología , Músculo Cuádriceps/anatomía & histología , Entrenamiento de Fuerza/métodos , Adulto , Biopsia , Estudios de Casos y Controles , Humanos , Masculino , Fibras Musculares Esqueléticas/fisiología , Músculo Esquelético/diagnóstico por imagen , Músculo Cuádriceps/diagnóstico por imagen , Ultrasonografía , Adulto Joven
6.
J Strength Cond Res ; 28(12): 3484-95, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24910954

RESUMEN

The purpose of the study was to investigate the effects of power training with light vs. heavy loads during the tapering phases of a double periodized training year on track and field throwing performance. Thirteen track and field throwers aged 16-26 years followed 8 months of systematic training for performance enhancement aiming at 2 tapering phases during the winter and the spring competition periods. Athletes performed tapering with 2 different resistance training loads (counterbalanced design): 7 athletes used 30% of 1 repetition maximum (1RM) light-load tapering (LT), and 6 athletes used the 85% of 1RM heavy-load tapering (HT), during the winter tapering. The opposite was performed at the spring tapering. Before and after each tapering, throwing performance, 1RM strength, vertical jumping, rate of force development (RFD), vastus lateralis architecture, and rate of perceived exertion were evaluated. Throwing performance increased significantly by 4.8 ± 1.0% and 5.6 ± 0.9% after LT and HT, respectively. Leg press 1RM and squat jump power increased more after HT than LT (5.9 ± 3.2% vs. -3.4 ± 2.5%, and 5.1 ± 2.4% vs. 0.9 ± 1.4%, respectively, p ≤ 0.05). Leg press RFD increased more in HT (38.1 ± 16.5%) compared with LT (-2.9 ± 6.7%), but LT induced less fatigue than HT (4.0 ± 1.5 vs. 6.7 ± 0.9, p ≤ 0.05). Muscle architecture was not altered after either program. These results suggest that performance increases similarly after tapering with LT or HT in track and field throwers, but HT leads to greater increases in strength, whole body power, and RFD.


Asunto(s)
Rendimiento Atlético/fisiología , Entrenamiento de Fuerza/métodos , Atletismo , Extremidad Superior/fisiología , Adolescente , Adulto , Femenino , Humanos , Masculino , Fuerza Muscular/fisiología , Distribución Aleatoria , Adulto Joven
7.
J Sports Sci Med ; 12(1): 130-7, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24149736

RESUMEN

The purpose of the present study was to investigate the effects of 6 weeks strength vs. ballistic-power (Power) training on shot put throwing performance in novice throwers. Seventeen novice male shot-put throwers were divided into Strength (N = 9) and Power (n = 8) groups. The following measurements were performed before and after the training period: shot put throws, jumping performance (CMJ), Wingate anaerobic performance, 1RM strength, ballistic throws and evaluation of architectural and morphological characteristics of vastus lateralis. Throwing performance increased significantly but similarly after Strength and Power training (7.0-13.5% vs. 6.0-11.5%, respectively). Muscular strength in leg press increased more after Strength than after Power training (43% vs. 21%, respectively), while Power training induced an 8.5% increase in CMJ performance and 9.0 - 25.8% in ballistic throws. Peak power during the Wingate test increased similarly after Strength and Power training. Muscle thickness increased only after Strength training (10%, p < 0.05). Muscle fibre Cross Sectional Area (fCSA) increased in all fibre types after Strength training by 19-26% (p < 0.05), while only type IIx fibres hypertrophied significantly after Power training. Type IIx fibres (%) decreased after Strength but not after Power training. These results suggest that shot put throwing performance can be increased similarly after six weeks of either strength or ballistic power training in novice throwers, but with dissimilar muscular adaptations. Key pointsBallistic-power training with 30% of 1RM is equally effective in increasing shot put performance as strength training, in novice throwers, during a short training cycle of six weeks.In novice shot putters with relatively low initial muscle strength/mass, short-term strength training might be more important since it can increase both muscle strength and shot put performance.The ballistic type of power training resulted in a significant increase of the mass of type IIx muscle fibres and no change in their proportion. Thus, this type of training might be used effectively during the last weeks before competition, when the strength training load is usually reduced, in order to increase muscle power and shot put performance in novice shot putters.

8.
J Strength Cond Res ; 26(3): 684-90, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22310514

RESUMEN

The purpose of this study was to investigate the acute effects of countermovement jumping and sprinting on shot put performance in experienced shot putters. Ten shot putters (best performance 13.16-20.36 m) participated in the study. After a standard warm-up including jogging, stretching, and 4-6 submaximal puts, they performed 3 shot put attempts with maximum effort, separated with 1.5-minute interval. Three minutes later, they performed 3 maximal consecutive countermovement jumps (CMJs). Immediately after jumping, they performed 3 shot put attempts with maximum effort, separated with a 1.5-minute interval. One week later, they carried out a similar protocol, at similar external conditions, but they performed a bout of 20-m sprinting instead of the CMJs, to potentiate shot put performance. Muscular strength (1 repetition maximum in squat, snatch, bench press, incline bench press) and body composition (dual x-ray absorptiometry) were measured during the same training period (±10 days from the jumping and sprinting protocols). Shot put performance was significantly increased after the CMJs (15.45 ± 2.36 vs. 15.85 ± 2.41 m, p = 0.0003). Similarly, shot put performance was significantly increased after sprinting (15.34 ± 2.41 vs. 15.90 ± 2.46 m, p = 0.0007). The increase in performance after sprinting was significantly higher compared with the increase after jumping (2.64 ± 1.59 vs. 3.74 ± 1.88%, p = 0.02). In conclusion, the results of this study indicate that a standard warm-up protocol followed by 3 maximal bouts of shot put and either 3 consecutive countermovement jumps or a bout of 20-m sprinting induce an acute increase in shot put performance in experienced shot putters.


Asunto(s)
Rendimiento Atlético/fisiología , Ejercicio Físico/fisiología , Carrera/fisiología , Atletismo/fisiología , Humanos , Masculino , Movimiento/fisiología , Adulto Joven
9.
Eur J Appl Physiol ; 110(4): 835-43, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20617335

RESUMEN

Regular performance of resistance exercise induces an increase in skeletal muscle mass, however, the molecular mechanisms underlying this effect are not yet fully understood. The purpose of the present investigation was to examine acute changes in molecular signalling in response to resistance exercise involving different training volumes. Eight untrained male subjects carried out one, three and five sets of 6 repetition maximum (RM) in leg press exercise in a random order. Muscle biopsies were taken from the vastus lateralis both prior to and 30 min after each training session and the effect on protein signalling was studied. Phosphorylation of Akt was not altered significantly after any of the training protocols, whereas that of the mammalian target of rapamycin was enhanced to a similar extent by training at all three volumes. The phosphorylation of p70S6 kinase (p70(S6k)) was elevated threefold after 3 × 6 RM and sixfold after 5 × 6 RM, while the phosphorylation of S6 was increased 30- and 55-fold following the 3 × 6 RM and 5 × 6 RM exercises, respectively. Moreover, the level of the phosphorylated form of the gamma isoform of p38 MAPK was enhanced three to fourfold following each of the three protocols, whereas phosphorylation of ERK1/2 was unchanged 30 min following exercise. These findings indicate that when exercise is performed in a fasted state, the increase in phosphorylation of signalling molecules such as p70(S6k) and the S6 ribosomal protein in human muscle depends on the exercise volume.


Asunto(s)
Ejercicio Físico/fisiología , Músculo Esquelético/enzimología , Entrenamiento de Fuerza , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Proteína S6 Ribosómica/metabolismo , Biopsia , Ayuno/fisiología , Humanos , Hipertrofia , Masculino , Músculo Esquelético/citología , Fosforilación/fisiología , Transducción de Señal/fisiología , Adulto Joven
10.
J Sports Sci Med ; 9(1): 104-9, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-24149393

RESUMEN

Aim of the present study was to describe the muscle fibre type composition and body composition of well-trained hammer throwers. Six experienced hammer throwers underwent the following measurements: one repetition maximum in squat, snatch, and clean, standing broad jump, backward overhead shot throw and the hammer throw. Dual x-ray absorptiometry was used for body composition analysis. Fibre type composition and cross sectional area was determined in muscle biopsy samples of the right vastus lateralis. Eight physical education students served as a control group. One repetition maximum in squat, snatch and clean for the hammer throwers was 245 ± 21, 132 ± 13 and 165 ± 12kg, respectively. Lean body mass was higher in hammer throwers (85.9 ± 3. 9kg vs. 62.7 ± 5.1kg (p < 0.01). The percentage area of type II muscle fibres was 66.1 ± 4% in hammer throwers and 51 ± 8% in the control group (p < 0.05). Hammer throwers had significantly larger type IIA fibres (7703 ± 1171 vs. 5676 ± 1270µm(2), p < 0.01). Hammer throwing performance correlated significantly with lean body mass (r = 0.81, p < 0.05). These data indicate that hammer throwers have larger lean body mass and larger muscular areas occupied by type II fibres, compared with relatively untrained subjects. Moreover, it seems that the enlarged muscle mass of the hammer throwers contributes significantly to the hammer throwing performance. Key pointsWell-trained hammer throwers had increased lean body mass, higher type IIA muscle fibres cross sectional areas, as well as higher bone mineral density, compared to controls.Increased lean body mass was closely related with hammer throwing performance.The relative high percentage of type IIX muscle fibres in vastus lateralis in hammer throwers warrants further investigation.

11.
J Orthop ; 20: 50-53, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32042229

RESUMEN

The aim of this study is to evaluate whether computer-assisted navigated TKA reduces perioperative blood loss. Patients were randomly divided into 2 groups and underwent either a conventional TKA (n = 40) or a TKA with computer-assisted navigation (n = 40). Perioperative blood loss was evaluated by laboratory parameters, postoperative drain output and number of required transfusions. Change in hemoglobin concentration and in hematocrit levels was similar. Also, there was no statistically significant difference in drain output and in the number of transfused units. The results of this study showed that TKA with computer-assisted navigation is similar to the conventional TKA regarding perioperative hemorrhage.

12.
J Strength Cond Res ; 23(9): 2592-7, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19858755

RESUMEN

The purpose of the present study was to investigate the acute effect of drop jumping on throwing performance. Eight men and 8 women, moderately trained subjects with basic shot put skills, performed 3 squat underhand front shot throws after a short standard warm-up. Three minutes later they performed 5 maximal consecutive drop jumps from 40 cm. Immediately after the drop jumps, they repeated the squat underhand front shot throws. On another day, their 6 repetition maximum (RM) muscular strength in leg press was assessed. Muscle biopsies were also obtained from vastus lateralis for the determination of fiber-type composition and fiber cross-sectional area. Throwing performance was significantly increased after drop jumping (8.25 +/- 1.1 m vs. 8.63 +/- 1.3 m, p < 0.01). The percentage of type II muscle fiber area was significantly related to the increase in throwing performance after drop jumping (r = 0.76, p < 0.01). The increase in throwing performance was significant in men (8.94 +/- 1 m vs. 9.60 +/- 0.9 m, p < 0.01) but not in women (7.56 +/- 1 m vs. 7.67 +/- 0.9 m, ns). Of note, the percentage of type II fiber area was higher in men than in women (M: 66.4 +/- 13%, F: 50.2 +/- 15%, p < 0.01). Leg press strength (6RM) was moderately related to the increase in throwing performance after drop jumping (r = 0.50, p < 0.05). These results suggest that drop jumping just before a throwing action induces an increase in performance in subjects with a high percentage of type II muscle fiber area and (to a lesser degree) in subjects with enhanced muscular strength.


Asunto(s)
Rendimiento Atlético/fisiología , Pierna/fisiología , Fuerza Muscular/fisiología , Entrenamiento de Fuerza/métodos , Atletismo/fisiología , Adulto , Fenómenos Biomecánicos , Conducta Competitiva/fisiología , Femenino , Histocitoquímica , Humanos , Masculino , Fibras Musculares de Contracción Rápida/fisiología , Fibras Musculares de Contracción Rápida/ultraestructura , Músculo Cuádriceps/fisiología , Músculo Cuádriceps/ultraestructura , Caracteres Sexuales
13.
Eur J Appl Physiol ; 102(2): 145-52, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17874120

RESUMEN

The purpose of the present study was to investigate the possible relationship between a change in Thr(389) phosphorylation of p70S6 kinase (p70(S6k)) after a single resistance training session and an increase in skeletal muscle mass following short-term resistance training. Eight male subjects performed an initial resistance training session in leg press, six sets of 6RM with 2 min between sets. Muscle biopsies were obtained from the vastus lateralis before (T1) and 30 min after the initial training session (T2). Six of these subjects completed a 14-week resistance-training programme, three times per week (nine exercises, six sets, 6RM). A third muscle biopsy was obtained at the end of the 14-week training period (T3). One repetition maximum (1RM) squat, bench press and leg press strength as well as fat-free mass (FFM, with dual energy X-ray absorptiometry) were determined at T1 and T3. The results show that the increase in Thr(389) phosphorylation of p70(S6k) after the initial training session was closely correlated with the percentage increase in whole body FFM (r = 0.89, P < 0.01), FFM(leg) (r = 0.81, P < 0.05), 1RM squat (r = 0.84, P < 0.05), and type IIA muscle fibre cross sectional area (r = 0.82, P < 0.05) after 14 weeks of resistance training. These results may suggest that p70(S6k) phosphorylation is involved in the signalling events leading to an increase in protein accretion in human skeletal muscle following resistance training, at least during the initial training period.


Asunto(s)
Ejercicio Físico/fisiología , Contracción Muscular/fisiología , Músculo Esquelético/anatomía & histología , Músculo Esquelético/fisiología , Esfuerzo Físico/fisiología , Proteínas Quinasas S6 Ribosómicas 70-kDa/fisiología , Prueba de Esfuerzo , Humanos , Masculino , Fosforilación , Estadística como Asunto , Adulto Joven
14.
J Strength Cond Res ; 22(4): 1198-204, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18545188

RESUMEN

The purpose of the present study was to investigate the effect of short-term resistance training and detraining on shot put throwing performance. Eleven young healthy subjects with basic shot put skills participated in 14 weeks of resistance training, which was followed by 4 weeks of detraining. Shot put performance in four field tests was measured before (T1) and after (T2) resistance training and after detraining (T3). At the same time points, one repetition maximum (1RM) was measured in squat, bench press, and leg press. Fat-free mass (FFM) was determined with dual x-ray absorptiometry and muscle biopsies obtained from vastus lateralis for the determination of fiber type composition and cross-sectional area (CSA). 1RM strength increased 22-34% (p < 0.01) at T2 and decreased 4-5% (not significantly different) at T3. Shot put performance increased 6-12% (p < 0.05) after training and remained unaltered after detraining. FFM increased at T2 (p < 0.05) but remained unchanged between T2 and T3. Muscle fiber CSA increased 12-18% (p < 0.05) at T2. Type I muscle fiber CSA was not altered after detraining, but type IIa and IIx fiber CSA was reduced 10-12% (p < 0.05). The percentage of type IIx muscle fibers was reduced after training (T1 = 18.7 +/- 4, T2 = 10.4 +/- 1; p < 0.05), and it was increased at T3 compared with T2 (T3 = 13.7 +/- 1; p < 0.05). These results suggest that shot put performance remains unaltered after 4 weeks of complete detraining in moderately resistance-trained subjects. This might be linked to the concomitant reduction of muscle fiber CSA and increase in the percentage of type IIx muscle fibers.


Asunto(s)
Brazo/fisiología , Rendimiento Atlético/fisiología , Movimiento/fisiología , Educación y Entrenamiento Físico/métodos , Absorciometría de Fotón , Adulto , Biopsia , Índice de Masa Corporal , Humanos , Masculino , Fibras Musculares Esqueléticas/fisiología , Músculo Esquelético/anatomía & histología
15.
J Strength Cond Res ; 22(3): 845-50, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18438231

RESUMEN

The purpose of this study was to investigate the relationship between skeletal muscle fiber type composition and the maximum number of repetitions performed during submaximal resistance exercise. Twelve young men performed a maximum repetitions test at 85% of 1 repetition maximum (1RM) in the leg press, which was repeated after 1 week. Seven days after the second 85% 1RM test, they performed a maximum repetitions test at 70% of 1RM in the leg press. This test, at 70% 1RM, was repeated 7 days later. One week before the initiation of the testing sessions, a biopsy sample was obtained from the vastus lateralis muscle and analyzed for fiber type distribution, fiber cross-sectional area, and capillary density (capillaries x mm(2)). A low and nonsignificant relationship was found between the fiber type distribution or percent fiber type area and the number of repetitions performed at either 70% or 85% 1RM. Moreover, the number of repetitions performed at 70% or 85% of 1RM was not related significantly with 1RM strength. In contrast, the number of repetitions performed at 70% 1RM was significantly correlated with the number of capillaries per mm(2) of muscle cross-sectional area (r = 0.70; p = 0.01). These results suggest that fiber type composition is not the major biological variable regulating the number of repetitions performed in submaximal resistance exercise. Rather, it seems that submaximal strength performance depends on muscle capillary density, which is linked with the endurance capacity of the muscle tissue.


Asunto(s)
Capilares/patología , Prueba de Esfuerzo/métodos , Músculo Cuádriceps/irrigación sanguínea , Músculo Cuádriceps/patología , Levantamiento de Peso/fisiología , Adulto , Análisis de Varianza , Biopsia con Aguja , Capilares/fisiología , Estudios de Cohortes , Humanos , Inmunohistoquímica , Masculino , Contracción Muscular/fisiología , Fibras Musculares Esqueléticas/patología , Fibras Musculares Esqueléticas/fisiología , Probabilidad , Músculo Cuádriceps/fisiología , Flujo Sanguíneo Regional/fisiología , Sensibilidad y Especificidad
16.
Int J Sports Physiol Perform ; 7(4): 394-6, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22832201

RESUMEN

PURPOSE: Although muscle mass and strength are thought to be closely related to throwing performance, there are few scientific data about these parameters in elite shot-putters. The purpose of this case report was to present longitudinal data for muscle strength and body composition in relation to performance of an elite male shot-putter. METHODS: A male national champion with the best rotational shot-put performance of 20.36 m (in 2010) was followed from 2003 to 2011 (current age: 29 y). Data regarding body composition (dual X-ray absorptiometry), as well as 1-repetition-maximum muscle strength (bench press, squat, snatch) and rotational shot-put performance, were collected every February for the last 9 y, 4 wk before the national indoor championship event. RESULTS: The athlete's personal-best performances in squat, bench press, and snatch were 175 kg, 210 kg, and 112.5 kg, respectively. His peak total lean body mass was 92.4 kg, bone mineral density 1.55 g/cm2, and lowest body fat 12.9%. His shot-put performance over these 9 years was significantly correlated with 1-repetition-maximum squat strength (r = .93, P < .01), bench press (r = .87, P < .01), and snatch (r = .92, P < .01). In contrast, shot-put performance was not significantly correlated with any of the body-composition parameters. CONCLUSIONS: The results of this case study suggest that elite rotational shot-put performance may not be directly correlated with lean body mass. Instead, it seems that it is closely related with measures of muscle strength.


Asunto(s)
Rendimiento Atlético , Composición Corporal , Contracción Muscular , Fuerza Muscular , Músculo Esquelético/fisiología , Atletismo , Absorciometría de Fotón , Adiposidad , Adulto , Fenómenos Biomecánicos , Densidad Ósea , Humanos , Masculino , Rotación , Análisis y Desempeño de Tareas , Factores de Tiempo
17.
Int J Sports Physiol Perform ; 5(3): 417-21, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20861531

RESUMEN

PURPOSE: The purpose of the current study was to investigate the relationship between fat-free mass and shot put performance at the beginning of the winter preparation cycle and at the first peak of the season (12 wk later) in well-trained shot-putters using the rotational style. METHODS: Eight national-level shot put athletes followed their individual training programs for a period of 12 wk aiming at the national indoor championship. Shot put performance with the rotational style as well as from the power position was determined before and after this 12 wk period. Body composition was determined before and after the training period with dual x-ray absorptiometry. RESULTS: Shot put from the power position was increased by 3% (P = .03) while shot put with the rotational style was increased by 6.5% (P < .01). Fat-free mass, body fat and bone mineral density were not altered after the training period. The correlation coefficient between fat-free mass and shot put performance from the power position was significant (r = .76 preseason vs r = .66, competition; P < .05). The correlation coefficient between fat-free mass and shot put performance with the rotational style was significant at the beginning of the training period (r = .70, P < .05) but it was decreased to moderate and nonsignificant levels at competition (r = .55, ns). CONCLUSIONS: These results suggest that the increase of fat-free mass might not be the most essential element for competition when the rotational shot put style is involved.


Asunto(s)
Rendimiento Atlético/fisiología , Composición Corporal , Fuerza Muscular/fisiología , Atletismo/fisiología , Absorciometría de Fotón , Adulto , Conducta Competitiva/fisiología , Grecia , Humanos , Masculino
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