Merits of interactive decision tree building — Part 2: How to do it

Abstract

Smilios, I., T. Pilianidis, K. Sotiropoulos, M. Anto-nakis, and S.P. Tokmakidis. Short-term effects of selected ex-ercise and load in contrast training on vertical jump perfor-mance. J. Strength Cond. Res. 19(1):135–139. 2005.—The pres-ent study examined the short-term effects of loaded half squats (HSs) and loaded jump squats (JSs) with low and moderate loads on the squat jump (SJ) and the countermovement jump (CMJ) performance using a contrast training approach. Ten men (mean Ϯ SD age, 23 Ϯ 1.8 years) performed the HS and JS exercises twice with loads of 30% of 1 repetition maximum (1RM) (HS30% and JS30%, respectively) and 60% of 1RM (HS60% and JS60%, respectively). On each occasion, 3 sets of 5 repetitions with 3 minutes of rest were performed as fast as possible. Vertical jump performance was measured before exercise, 1 minute after each set, and at the fifth and 10th minutes of recovery. The CMJ increased significantly after the first and second set (3.9%; p Ͻ 0.05) compared with preexercise values following the JS30% pro-tocol and 3.3% after the second and third sets of the JS60% protocol. Following the HS60% protocol, CMJ increased after the first and the second sets (3.6%; p Ͻ 0.05) compared with preex-ercise values, whereas SQ increased only after the first set (4.9%; p Ͻ 0.05) in this condition. These data show that contrast loading with the use of low and moderate loads can cause a short-term increase in CMJ performance. The applied loads do not seem to present different short-term effects after loaded JSs. When the classic form of dynamic HS exercise is performed, however, at least a moderate load (60% of 1RM) needs to be applied.