Effects of Cluster Set Configuration on Mechanical Performance and Neuromuscular Activity

2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Manuel Ortega-Becerra ◽  
Miguel Sánchez-Moreno ◽  
Fernando Pareja-Blanco
2014 ◽  
Vol 9 (4) ◽  
pp. 637-642 ◽  
Author(s):  
Eliseo Iglesias-Soler ◽  
Eduardo Carballeira ◽  
Tania Sánchez-Otero ◽  
Xian Mayo ◽  
Miguel Fernández-del-Olmo

Purpose:To analyze performance during the execution of a maximum number of repetitions (MNR) in a cluster-set configuration.Method:Nine judokas performed 2 sessions of parallel squats with a load corresponding to 4-repetition maximum (4RM) with a traditional-training (TT) and cluster-training (CT) set configuration. The TT consisted of 3 sets of repetitions leading to failure and 3 min of rest between sets. In the CT the MNR was performed with a rest interval between repetitions (45.44 ± 11.89 s). The work-to-rest ratio was similar for CT and TT.Results:MNR in CT was 45.5 ± 32 repetitions and was 9.33 ± 1.87 times the volume in TT. There was a tendency for the average mean propulsive velocity (MPV) to be higher in CT (0.39 ± 0.04 vs 0.36 ± 0.04 m/s for CT and TT, respectively, P = .054, standardized mean difference [d] = 0.57). The average MPV was higher in CT for a similar number of repetitions (0.44 ± 0.08 vs 0.36 ± 0.04 m/s for CT and TT, respectively, P = .006, d = 1.33). The number of repetitions in TT was correlated with absolute 4RM load (r = –.719, P = .031) but not in CT (r = –.273, P = .477).Conclusions:A cluster-set configuration allows for a higher number of repetitions and improved sustainability of mechanical performance. CT, unlike TT, was not affected by absolute load, suggesting an improvement of training volume with high absolute loads.


2019 ◽  
Author(s):  
Peter Peter ◽  
Claudia Creighton ◽  
David Fox ◽  
Pablo Mota Santiago ◽  
Adrian Hawley ◽  
...  

Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.


Author(s):  
Byung-Jae Kim ◽  
Hyeon-Seok Seo ◽  
Won-Ho Lee ◽  
Jong-Hyun Ahn ◽  
Youn-Jea Kim

Diabetes ◽  
1984 ◽  
Vol 33 (12) ◽  
pp. 1138-1143 ◽  
Author(s):  
B. H. Tan ◽  
G. L. Wilson ◽  
S. W. Schaffer

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