102 ORIGINAL INVESTIGATION International Journal of Sports Physiology and Performance, 2016, 11, 102 -107 http://dx.doi.org/10.1123/ijspp.2015-0058 © 2016 Human Kinetics, Inc. The Effects of Frontal- and Sagittal-Plane Plyometrics on Change-of-Direction Speed and Power in Adolescent Female Basketball Players Brian T. McCormick, James C. Hannon, Maria Newton, Barry Shultz, Nicole Detling, and Warren B. Young Plyometrics is a popular training modality for basketball players to improve power and change-of-direction speed. Most plyo- metric training has used sagittal-plane exercises, but improvements in change-of-direction speed have been greater in multi- direction programs. Purpose: To determine the benefts of a 6-wk frontal-plane plyometric (FPP) training program compared with a 6-wk sagittal-plane plyometric (SPP) training program with regard to power and change-of-direction speed. Methods: Fourteen female varsity high school basketball players participated in the study. Multiple 2 × 2 repeated-measures ANOVAs were used to determine differences for the FPP and SPP groups from preintervention to postintervention on 4 tests of power and 2 tests of change-of-direction speed. Results: There was a group main effect for time in all 6 tests. There was a signifcant group × time interaction effect in 3 of the 6 tests. The SPP improved performance of the countermovement vertical jump more than the FPP, whereas the FPP improved performance of the lateral hop (left) and lateral-shuffe test (left) more than the SPP. The standing long jump, lateral hop (right), and lateral-shuffe test (right) did not show a signifcant interaction effect. Conclu- sions: These results suggest that basketball players should incorporate plyometric training in all planes to improve power and change-of-direction speed. Keywords: agility, girls’ basketball, vertical jump, lateral shuffe, horizontal jump McCormick, Hannon, Newton, Shultz, and Detling are with the Dept of Exercise and Sport Science, University of Utah, Salt Lake City, UT. Young is with the Discipline of Human Movement and Sport Sciences, Federation University Australia, Ballarat, VIC, Australia. Address author correspon- dence to Brian McCormick at brian.mccormick@utah.edu. Agility is a motor ability important to success in team sports 1 and has been defned traditionally as speed in changing directions. 2 Basketball requires multidirectional movement skills and the ability to stop and start quickly. Despite its perception as a vertical game, basketball players have been shown to execute as many or more changes in direction and speed than maximal vertical jumps (VJs) during a game. 3 Men’s basketball games have been found to require a change in movement every 2 seconds. 3,4 Despite the importance of these change-of-direction movements, training for basketball players has emphasized the VJ. National Basketball Association (NBA) strength and conditioning coaches have reported extensive use of VJ training and testing, whereas no direct mention was made of training specifcally for change-of-direction speed (CODS), and only half of the sample tested for CODS. 5 Plyometrics has been a popular training modality for athletes and has dominated basketball strength and conditioning programs. 5–7 Plyometrics is characterized by quick, powerful movements involving a prestretch of the muscle, followed by a shortening, concentric muscle contraction, thus using the stretch-shortening cycle. 8 Training interventions incorporating plyometrics have been shown to elicit improvements in CODS, 9,10 VJ height, 7 and long- jump distance. 9 Plyometric training programs have emphasized sagittal- plane exercises such as box jumps, repeat hurdle hops, and depth jumps. 5–7,11 Few studies have examined the effects of plyometric training performed in different planes of movement. A multidirec- tional jump-training program was found to improve performance in 2 tests of CODS, 10 but the study did not investigate the effects of the plane of movement of the training. A 6-week program of frontal-plane plyometrics (FPP) and sagittal-plane plyometrics (SPP) found that only the SPP program improved VJ height in male high school basketball players. 7 A test of power in the frontal plane may have identifed improved power by the FPP group, 7 which was not expressed in the VJ test due to the principle of specifcity. 12 The purpose of this study was to compare the effects of 6-week FPP and SPP training programs on CODS and power. The study attempted to answer 2 key questions: (1) Does plyometric training improve performance during a test of CODS? The hypothesis was that the FPP training program compared with the SPP training program would show improved performance in the lateral-shuffe test (LST). (2) Are the benefts of plyometric training specifc to the plane in which it is trained? The hypothesis was that the SPP training program would improve performance in the countermove- ment VJ (CMVJ) and standing long jump (SLJ), and the FPP would improve performance in the lateral hop (LH). Methods Participants The participants were female varsity high school basketball play- ers (N = 14) from 2 high schools (10 from 1 school and 4 from the other) in the western United States. The participant characteristics are shown in Table 1. Two high school basketball coaches volunteered to participate in the study with their varsity players. The study started with 29 play- ers, but only 14 completed the 6 weeks of training and posttesting.