Acute Effect of Upper and Lower Body Postactivation Exercises on Shot Put Performance.

Kontou, EI, Berberidou, FT, Pilianidis, TC, Mantzouranis, NI, and Methenitis, SK. Acute effect of upper and lower body postactivation exercises on shot put performance. J Strength Cond Res 32(4): 970-982, 2018-The purpose of this study was to investigate the effect of different types of upper and lower' extremities exercises on acute increase of shot put performance, in moderate experienced throwers. Eight (n = 8) males and 9 (n = 9) female throwers participated in this study. Their bench press and squat maximum strength were measured while their shot put performance from power position was evaluated before and after 4 interventions: (a) plyometric push-ups (Plyo), (b) 6 s isometric push-ups (Iso), (c) 3 countermovement jumps (CMJs) and (d) 10 reps. of skipping (Skip). Interventions were performed in counterbalanced order with a 48-hour interval. Significant increase (p < 0.05) of shot put performances was observed after Plyo, Iso, and CMJ (range: 2.30 ± 1.82%-5.72 ± 4.32%). In addition, Iso induced the highest increase while Skip did not induce any improvement of throwing performance. The highest increases were recorded in men's performance after CMJ (5.72 ± 4.32%) while in women's performance after Iso (3.59 ± 2.7%). Javelin and discus throwers increase higher their performance after CMJs while shot putters after Iso. Significant correlations were found between training experience, maximum/relative strength, shot put performance and increase of throwing performance (%) after the interventions (r: 0.519-0.991, p < 0.05). Percentage increase of performance between Iso and Plyo have negative correlations (r: -0.569, p < 0.05) in contrast of those between Skip and CMJ (r: 0.710, p < 0.05). These results suggest that upper or lower body postactivation interventions may acutely increase the throwing performance. However, experience and strength are significant determinant of this increase.

Nutritional Routine of Tae Kwon Do Athletes Prior to Competition: What Is the Impact of Weight Control Practices?

OBJECTIVE: The purpose of the present study was to investigate and assess the common dietary and weight management strategies of Tae Kwon Do (TKD) athletes prior to national competitions, as well as to examine the relationships between these strategies and body weight reduction and sensation of physical condition. METHODS: Sixty (n = 60) TKD athletes, 23 women (19.4 ± 2.9 years) and 37 men (20.4 ± 3.6 years), with at least 12.1 ± 3.1 years of experience, participated in the present study. The athletes recorded their dietary intake and physical activity for 3 training days and on a competition day. Bioelectrical impedance was used for body composition estimation. RESULTS: Male athletes consumed 1918 ± 685 kcal/24 hours and 1974 ± 669 kcal/24 hours on training and competition days, respectively, and women 1814 ± 446 kcal/24 hours and 1700 ± 439 kcal/24 hours. TKD athletes had significant negative energy balance (48.6% ± 17.8% to 60.3% ± 26.9%; p < 0.05), with the majority of macro- and micronutritional elements being lower than the recommended values, with significant differences between them, as well as within groups, between weekdays and weekend days (p < 0.05). Females lost most of their weight 2 weeks before the games (3.50 ± 1.00 kg), and males lost most of their weight 3 weeks before (3.16 ± 2.48 kg). The majority of TKD athletes were guided by their coaches for weight management strategies. No significant correlations were found between any body composition variable, weight loss, and any nutritional intake at any time point (p > 0.05). CONCLUSIONS: These data suggest that the methods of TKD athletes for rapid weight loss are guided by unspecialized professionals, leading to significant malnutrition, because certain deficiencies in both macro- and micronutrient content are present, with no guaranteed specific reduction of their body mass.

Role of Muscle Morphology in Jumping, Sprinting, and Throwing Performance in Participants With Different Power Training Duration Experience.

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.

Rate of Force Development, Muscle Architecture, and Performance in Young Competitive Track and Field Throwers.

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.

Effects of tapering with light vs. heavy loads on track and field throwing performance.

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.

Validity and Reliability of New Equations for the Prediction of Maximal Oxygen Uptake in Male and Female Elite Adolescent Rowers.

The aim of this study was to develop accurate, reliable, and reproductive equations for the prediction of maximum oxygen uptake ( V ˙ O2max) in male and female high-level adolescent rowers. This study included two parts. In the first part, V̇O2max was evaluated in 106 male and 83 female high-level adolescent rowers during an incremental step test (IRT) on a rowing ergometer, and stepwise multiple regression analyses were used for the development of new equations. In the second part, these equations were tested in 26 new high-level adolescent rowers of the same age and anthropometrical characteristics (boys: 15.27 ± 2.70 yrs and 15.34 ± 2.80 yrs; 72.37 ± 10.96 kg and 70.96 ± 10.65 kg; girls: 15.00 ± 2.11 yrs and 15.94 ± 2.71 yrs; 62.50 ± 7.14 kg and 63.41 ± 6.72 kg for parts 1 and 2, respectively; p > 0.05). V̇O2max was predicted from the combination of lean body mass (LBM) and the distance covered during the last 4 min stage of the IRT (boys: r2 = 0.715, F = 68.74, p = 0.001; girls: r2 = 0.769, F = 57.81, p = 0.001). In the second part, no significant differences were identified when the new equations were tested against measured V̇O2max (boys: 3971.15 ± 713.38 mL·min-1 vs. 3915.83 ± 704.43 mL·min-1; girls: 3272.75 ± 551.46 mL·min-1 vs. 3308.94 ± 557.59 mL·min-1 for measured and predicted values, respectively; p > 0.05). In conclusion, V̇O2max of high-level adolescent rowers can be predicted with high accuracy, reliability, and repeatability using simple and easily evaluated anthropometric and performance variables.

Effects of low volume isometric leg press complex training at two knee angles on force-angle relationship and rate of force development.

This study compared knee angle-specific neuromuscular adaptations after two low-volume isometric leg press complex training programmes performed at different muscle lengths. Fifteen young males were divided into two groups and trained three times per week for 6 weeks. One group (n = 8) performed 5-7 sets of 3 s maximum isometric leg press exercise, with 4 min recovery, with knee angle at 85° ± 2° (longer muscle-tendon unit length; L-MTU). The other group (n = 7) performed the same isometric training at a knee angle of 145° ± 2° (180° = full extension; shorter muscle-tendon unit length; S-MTU). During the recovery after each set of isometric exercise, participants performed two CMJ every minute, as a form of complex training. Maximum isometric force (MIF) and rate of force development (RFD) were measured over a wide range of knee angles. Countermovement jump (CMJ) performance and maximum half-squat strength (1RM) were also assessed. Training at S-MTU induced a large increase of MIF (22-58%, p < 0.02) and RFD (18-43%, p < 0.05 to 0.001) at knee angles close to the training angle and resulted in a 14° ± 9° shift of the force vs. knee joint angle relationship towards extended knee joint angles (p = 0.001). In contrast, training at L-MTU, resulted in a moderate and similar (≈12.3%, p = 0.028) improvement of force at all knee angles. CMJ performance and 1RM were equally increased in both groups after training by 10.4% ± 8.3% and 7.8% ± 4.7% (p < 0.001), respectively. Low-volume maximal isometric leg-press complex training at S-MTU causes angle-specific adaptations in isometric strength and RFD, while dynamic muscle performance is independent of muscle length during training.