Reliability and concurrent validity of the Velowin optoelectronic system to measure movement velocity during the free-weight back squat
The objective of this study was to explore the reliability and concurrent validity of the Velowin optoelectronic system to measure movement velocity during the free-weight back squat exercise. Thirty-one men (age = 27.5 ± 3.2 years; body height = 1.76 ± 0.15 m; body mass: 78.3 ± 7.6 kg) were evaluated in a single session against five different loads (20, 40, 50, 60 and 70 kg) and three velocity variables (mean velocity, mean propulsive velocity and maximum velocity) were recorded simultaneously by a linear velocity transducer (T-Force; gold-standard) and a camera-based optoelectronic system (Velowin). The main findings revealed that (1) the three velocity variables were determined with a h…
Effects of short inter-repetition rest periods on power output losses during the half squat exercise
BACKGROUND: Cluster training is being increasingly used to develop muscular power. OBJECTIVE: To determine the effects of short inter-repetition rest (IRR) periods on the capacity to maintain maximal levels of power output. METHODS:In afirst session, 16 active-duty soldiers performed a progressive loading test toestablish the load linked tomaximal power (optimal load, OL), and the half squat 1-repetition maximum. In Session 2, six individual sets of repetitions performed to failure (or a maximum of 20 repetitions) were conducted using the loads OL, low (LL, 15% below OL), and high (HL, 15% above OL) as quickly as possible. For each load, participants performed one set without rest between r…