Balsalobre-Fernández Carlos, Marchante David, Muñoz-López Mario, Jiménez Sergio L
a Department of Sport Sciences , Universidad Europea de Madrid , Madrid , Spain.
b Department of Research & Development , Powerexplosive Center , Madrid , Spain.
J Sports Sci. 2018 Jan;36(1):64-70. doi: 10.1080/02640414.2017.1280610. Epub 2017 Jan 18.
The purpose of this study was to analyse the validity and reliability of a novel iPhone app (named: PowerLift) for the measurement of mean velocity on the bench-press exercise. Additionally, the accuracy of the estimation of the 1-Repetition maximum (1RM) using the load-velocity relationship was tested. To do this, 10 powerlifters (Mean (SD): age = 26.5 ± 6.5 years; bench press 1RM · kg = 1.34 ± 0.25) completed an incremental test on the bench-press exercise with 5 different loads (75-100% 1RM), while the mean velocity of the barbell was registered using a linear transducer (LT) and Powerlift. Results showed a very high correlation between the LT and the app (r = 0.94, SEE = 0.028 m · s) for the measurement of mean velocity. Bland-Altman plots (R = 0.011) and intraclass correlation coefficient (ICC = 0.965) revealed a very high agreement between both devices. A systematic bias by which the app registered slightly higher values than the LT (P < 0.05; mean difference (SD) between instruments = 0.008 ± 0.03 m · s). Finally, actual and estimated 1RM using the app were highly correlated (r = 0.98, mean difference (SD) = 5.5 ± 9.6 kg, P < 0.05). The app was found to be highly valid and reliable in comparison with a LT. These findings could have valuable practical applications for strength and conditioning coaches who wish to measure barbell velocity in the bench-press exercise.
本研究旨在分析一款用于测量卧推练习平均速度的新型iPhone应用程序（名为：PowerLift）的有效性和可靠性。此外，还测试了利用负荷-速度关系估算1次重复最大值（1RM）的准确性。为此，10名力量举运动员（平均（标准差）：年龄 = 26.5 ± 6.5岁；卧推1RM·kg = 1.34 ± 0.25）在卧推练习中使用5种不同负荷（75 - 100% 1RM）完成了递增测试，同时使用线性传感器（LT）和Powerlift记录杠铃的平均速度。结果显示，在测量平均速度方面，LT与该应用程序之间具有非常高的相关性（r = 0.94，标准误 = 0.028 m·s）。Bland - Altman图（R = 0.011）和组内相关系数（ICC = 0.965）表明两种设备之间具有非常高的一致性。存在一种系统偏差，即该应用程序记录的值略高于LT（P < 0.05；仪器之间的平均差异（标准差） = 0.008 ± 0.03 m·s）。最后，使用该应用程序实际估算的1RM与实际值高度相关（r = 0.98，平均差异（标准差） = 5.5 ± 9.6 kg，P < 0.05）。与LT相比，该应用程序被发现具有高度的有效性和可靠性。这些发现对于希望在卧推练习中测量杠铃速度的力量和体能教练可能具有宝贵的实际应用价值。
