Abstract
The purpose of this study was to analyze the validity, reliability, and accuracy of new wearable and smartphone-based technology for the measurement of barbell velocity in resistance training exercises. To do this, 10 highly trained powerlifters (age = 26.1 ± 3.9 years) performed 11 repetitions with loads ranging 50–100% of the 1-Repetition maximum in the bench-press, full-squat, and hip-thrust exercises while barbell velocity was simultaneously measured using a linear transducer (LT), two Beast wearable devices (one placed on the subjects' wrist –BW–, and the other one directly attached to the barbell –BB–) and the iOS PowerLift app. Results showed a high correlation between the LT and BW (r = 0.94–0.98, SEE = 0.04–0.07 m•s−1), BB (r = 0.97–0.98, SEE = 0.04–0.05 m•s−1), and the PowerLift app (r = 0.97–0.98, SEE = 0.03–0.05 m•s−1) for the measurement of barbell velocity in the three exercises. Paired samples T-test revealed systematic biases between the LT and BW, BB and the app in the hip-thrust, between the LT and BW in the full-squat and between the LT and BB in the bench-press exercise (p < 0.001). Moreover, the analysis of the linear regression on the Bland-Altman plots showed that the differences between the LT and BW (R2 = 0.004–0.03), BB (R2 = 0.007–0.01), and the app (R2 = 0.001–0.03) were similar across the whole range of velocities analyzed. Finally, the reliability of the BW (ICC = 0.910–0.988), BB (ICC = 0.922–0.990), and the app (ICC = 0.928–0.989) for the measurement of the two repetitions performed with each load were almost the same than that observed with the LT (ICC = 0.937–0.990). Both the Beast wearable device and the PowerLift app were highly valid, reliable, and accurate for the measurement of barbell velocity in the bench-press, full-squat, and hip-thrust exercises. These results could have potential practical applications for strength and conditioning coaches who wish to measure barbell velocity during resistance training.
Highlights
Quantifying and monitoring intensity is a key part when designing resistance training programs (Folland and Williams, 2007; Borresen and Lambert, 2009; Tillin and Folland, 2014); training intensity is considered the most important variable to produce the desired neuromuscular adaptations (Folland and Williams, 2007)
Systematic biases were observed for velocities measured with BW, BB, and the app in the hip-thrust and bench-press exercises, the absolute difference was small in all cases and, the analysis of the regression lines of the Bland-Altman plots showed that differences between the novel devices and the gold standard were homogeneous across all the ranges of velocities measured (R2 = 0.001–0.03)
These results are in line with previous research that showed very similar validity, reliability, and accuracy scores for the measurement of barbell velocity in the bench-press exercise using the PowerLift app (Balsalobre-Fernández et al, 2017) and confirms the suitability of high-speed video analysis to assess different activities such as jumping, sprinting, running, or lifting (Balsalobre-Fernández et al, 2015, 2016a; Romero-Franco et al, 2016; Sañudo et al, 2016)
Summary
Quantifying and monitoring intensity is a key part when designing resistance training programs (Folland and Williams, 2007; Borresen and Lambert, 2009; Tillin and Folland, 2014); training intensity is considered the most important variable to produce the desired neuromuscular adaptations (Folland and Williams, 2007). The measurement of the velocity at which the barbell is moved in the concentric phase on different resistance exercises has been shown to provide accurate, indirect estimations of the 1-RM without the need to perform a maximal lift (Gonzalez-Badillo and Sánchez-Medina, 2010; Jidovtseff et al, 2011; Picerno et al, 2016; Muñoz-López et al, 2017). Analyzing the drop of velocity within the sets could be used to optimize the adaptations to resistance training (SánchezMedina and Gonzalez-Badillo, 2011; Tufano et al, 2016)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
