Background The block phase in the swimming start requires a quick reaction to the starting signal and a large take-off velocity that is primarily horizontal in direction. Due to the principle of specificity of training, there is a potential benefit of performing a greater proportion of horizontal force production exercises in a swimmers’ dry-land resistance training sessions. Therefore, the purpose of this pilot study was to provide an insight into the effects of a horizontal- (HF) vs vertical-force (VF) training intervention on swim start performance. Methods Eleven competitive swimmers (six males (age 20.9 ± 1.8 years, body mass 77.3 ± 9.7 kg, height 1.78 ± 0.05 m) and five females (age 21.4 ± 2.0 years, body mass 67.5 ± 7.4 kg, height 1.69 ± 0.05 m)) completed 2 weekly sessions of either a horizontal- or vertical-force focused resistance training programme for 8 weeks. Squat jump force-time characteristics and swim start kinetic and kinematic parameters were collected pre- and post-intervention. Results Across the study duration, the swimmers completed an average of nine swimming sessions per week with an average weekly swim volume of 45.5 ± 17.7 km (HF group) and 53 ± 20.0 km (VF group), but little practice of the swim start per week (n = 9). Within-group analyses indicated a significant increase in predicted one repetition maximum (1RM) hip thrust strength in the HF group, as well as significant increases in grab resultant peak force but reductions in resultant peak force of the block phase for the VF group. No significant between-group differences in predicted 1RM hip thrust and back squat strength, squat jump force-time and swim start performance measures were observed after 8 weeks of training. Significant correlations in the change scores of five block kinetic variables to time to 5 m were observed, whereby increased block kinetic outputs were associated with a reduced time to 5 m. This may be indicative of individual responses to the different training programmes. Discussion The results of this current study have been unable to determine whether a horizontal- or vertical-force training programme enhances swim start performance after an 8-week training intervention. Some reasons for the lack of within and between group effects may reflect the large volume of concurrent training and the relative lack of any deliberate practice of the swim start. Larger samples and longer training duration may be required to determine whether significant differences occur between these training approaches. Such research should also look to investigate how a reduction in the concurrent training loads and/or an increase in the deliberate practice of the swim start may influence the potential changes in swim start performance.

中文翻译：

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上推或推出——对游泳开始表现的水平与垂直力量训练的初步调查：一项试点研究

背景 游泳起跑中的阻挡阶段需要对起跑信号的快速反应和主要水平方向的大起跳速度。由于训练的特殊性原则，在游泳者的旱地阻力训练课程中进行更大比例的水平力量产生练习有潜在的好处。因此，这项试点研究的目的是深入了解水平（HF）与垂直（VF）训练干预对游泳开始表现的影响。方法 11 名竞技游泳运动员（男性 6 名（年龄 20.9 ± 1.8 岁，体重 77.3 ± 9.7 kg，身高 1.78 ± 0.05 m）和女性 5 名（年龄 21.4 ± 2.0 岁，体重 67.5 ± 7.4 kg，身高 1.69 ± 0. 05 m)) 完成了为期 8 周的水平或垂直力量集中阻力训练计划的 2 次每周课程。在干预前后收集深蹲跳跃力-时间特征和游泳开始动力学和运动学参数。结果 在整个研究期间，游泳者平均每周完成 9 次游泳，平均每周游泳量为 45.5 ± 17.7 公里（HF 组）和 53 ± 20.0 公里（VF 组），但很少练习游泳开始。周（n = 9）。组内分析表明，HF 组预测的一次最大重复 (1RM) 髋部推力显着增加，以及 VF 组抓握合力峰值力显着增加，但阻滞阶段合力峰值力降低。在 8 周的训练后，没有观察到预测的 1RM 髋部推力和后蹲力量、下蹲跳跃力时间和游泳开始表现测量的显着组间差异。观察到五个块动力学变量的变化分数与时间到 5 m 的显着相关性，由此增加的块动力学输出与缩短到 5 m 的时间相关。这可能表明个人对不同培训计划的反应。讨论 本研究的结果无法确定在 8 周的训练干预后，水平或垂直力量训练计划是否能提高游泳开始表现。缺乏组内和组间效应的一些原因可能反映了大量的同时训练和相对缺乏任何有意识的游泳开始练习。可能需要更大的样本和更长的训练时间来确定这些训练方法之间是否存在显着差异。此类研究还应调查同时训练负荷的减少和/或游泳开始的刻意练习的增加如何影响游泳开始表现的潜在变化。