Validity of a Wireless Inertia Measurement Device in Quantifying Performance in Vertical Jumping Tests

The use of technology in sport and fitness training has rapidly become a tool for both athletes and coaches in monitoring performance variables for optimizing training stimulus and recovery (Duking, Hotho, Holmberg, Fuss, & Sperlich, 2016; Peake, Kerr & Sullivan, 2018). Wireless fitness trackers, GPS and accelerometry devices are growing in popularity with the athletic population outside of the clinical setting due to their lower cost and ease of use compared to traditional clinical measurement tools (Dellaserra, Gao & Ransdell, 2014). With the increased popularity of these devices comes the necessity to understand and validate the information collected from them (Kooiman et al., 2015). Previous research has validated the measurement capability of wireless inertia sensors in the collection of curvilinear and linear velocity during upper body resistance exercise compared to 3D motion capture, which suggests it as a useful tool in a coaching environment (Sato, Beckham, Carroll, Bazyler, & Sha, 2015). Furthermore, wired or anchored devices limit the variety of exercises that can be measured, and may also present potentially more difficulty in managing data collection amongst several athletes simultaneously (Sato et al., 2015). Studies have examined the reliability and validity of wireless inertial sensor measurement compared to currently validated wired measurement tools like the GymAware (Orange et al., 2018). The use of specific algorithms to detect and measure different exercises restricts the extrapolation of results related to validity and reliability from one exercise to another (Sato et al., 2015). Few studies have been performed in relation to the validity of wireless inertia devices on measurement of vertical jumping performance. Therefore, the purpose of this study was to investigate the validity of a wireless measurement device on several types of vertical jump exercise. Specifically, this investigation examined static, countermovement, and drop jumps as measured with a wireless sensor compared with commercially available force plates

Acute Effects of Ballistic and Non-ballistic Bench Press on Plyometric Push-up Performance

The purpose of this study was to examine the effects of a ballistic or non-ballistic concentric-only bench press (COBP) on subsequent plyometric push-up performance. Fourteen resistance trained men completed two separate one-repetition-maximum (1RM) testing sessions followed by three randomized experimental explosive push-up sessions. These sessions combined a heavy concentric bench press with plyometric push-ups. Using a series of 3 × 10 (condition × time) repeated measures ANOVA, comparisons were made between the effects of ballistic and non-ballistic bench presses on performance of plyometric push-ups to investigate push-up performance variables. Compared with the control condition, both ballistic and non-ballistic bench presses produced lower net impulse and take-off velocity data. No differences were found between ballistic and non-ballistic conditions comparing net impulse and take-off velocity. We conclude that the magnitude of loading used in the current investigation may have caused acute fatigue which led to lower push-up performance characteristics. This information can be used to alter loading protocols when designing complexes for the upper body, combining the bench press and plyometric push-ups

Accentuated Eccentric Loading and Cluster Set Configurations in the Bench Press

This study was designed to examine the kinetic and kinematic differences between an Accentuated eccentric loading (AEL), traditional loading, and cluster sets in trained male subjects (age: 23.7 ± 4.0 years, height: 176.4 ± 2.8 cm, mass: 93.6 ± 7.0 kg) with lifting experience (training age: 7.2 ± 2.4 years, 1-repetition maximum (1RM) bench press: 125.0 ± 14.8 kg, relative strength ratio: 1.3 ± 0.1) in the bench press. Subjects reported for a total of 5 sessions which consisted of a 1RM testing session and 4 experimental trials. The 4 experimental conditions consisted of a traditional load (TRAD), traditional load with inter-repetition rest (TRDC), accentuated eccentric loading with inter-repetition rest (AELC), and Accentuated eccentric loading for the first repetition only (AEL1). Concentric load was 80% of subjects\u27 1RM for all conditions. An eccentric overload of 105% of 1RM was applied using weight-releasing hooks during the AEL conditions. TRDC demonstrated superior concentric outputs for mean velocity and mean power compared with TRAD, AELC, and AEL1 (p \u3c 0.001). In addition, AEL1 produced significantly greater effects for rate of force development compared with TRDC (p \u3c 0.001). These findings suggest that inter-repetition rest had an influence on concentric performance, specifically mean power and mean velocity, and may be favorable when using higher loads and when sustained power outputs are desired. In addition, AEL1 may provide a unique eccentric stimulus that alters loading parameters compared with traditional loading conditions