Effects of an assisted jump training stimulus on explosive performance

Complex training protocols are an effective means to improve explosive performance. However, due to many variations in resistance and plyometric training the effectiveness of different combinations are unknown. Therefore, the purpose of this study was to compare ‘traditional’ complex training with a ‘novel’ complex training protocol based on over-speed principles. Seventeen healthy male subjects (20.8 ± 3.6 yrs, 176.2 ± 9.6 cm, and 80.6 ± 13.9 kg) participated in this study. Seven weeks of training was divided into two phases. The first phase of baseline strength training (three weeks) was followed by an intervention (four weeks) consisting of either a strength and vertical jump (SVJ, n=8) phase or a strength and assisted vertical jump (SAJ, n=9) phase. Assessments were conducted prior (PRE1), during (PRE2), and after the training phase (POST1) and included; vertical jump (VJ), 20 m sprint (20m), and squat strength (1RM). All subjects completed the same strength training protocol twice a week. During the four week intervention, jumps were completed 90sec after a lifting set (six sets of six jumps each session). The mean (±CI) vertical jump height improved by 1.6 cm or 3.9%; ±6.6% (SVJ, small effect) and 3.3 cm or 6.8%; 3.5% (SAJ, small effect). The 20 m sprint time improved by 0.03 sec or 0.9%; ±1.8% (SVJ, small effect) and 0.04 sec or 1.3%; ±1.2% (SAJ, small effect). The predicted 1RM squat strength of both groups also improved with increases of 12 kg or 8.9%; ±5.6% (SVJ, small effect) and 15 kg or 10%; ±5.6% (SAJ, moderate effect) found. However there were unclear effects between the two groups in all the performance tests. The strength and assisted jump stimulus was as effective as the traditional strength and vertical jump stimulus to improve strength, power and speed performance