title: Short-term Resistance and Plyometric Training Improves Eccentric Phase Kinetics in Jumping.
abstract: The purpose of this investigation was to examine the effect of an abbreviated resistance and plyometric training program on force- and power-time curve variables during jumping. Nineteen male subjects were assigned to either a training (n = 9) or control group (n = 10). Training consisted of performing 3 sets of 3 repetition squats (90% of 1 repetition maximum [RM]) and 5 sets of 6 repetition drop jumps from 40 cm twice per week for 4 weeks. A 1RM in the squat and countermovement (CMJ) and static jump (SJ) performance was assessed before and after training. Several variables were analyzed for individual subject force- and power-time curves for the jumps. Average force- and power-time curves for all subjects combined were also analyzed. Absolute and relative squat strength significantly increased in training group (p ≤ 0.05). Calculation of variables from individual subject force-time curves during the CMJ indicated a significant decrease in eccentric time, minimum force, and eccentric impulse and significant increase in eccentric rate of force development in training group. Analysis of individual power-time curves in the CMJ also revealed a significant decrease in minimum power and eccentric work and a significant increase in eccentric rate of power development. No significant changes occurred in the variables measured for the SJ. The results of this study indicate that short-term strength and plyometric training may preferentially influence eccentric performance variables during jumping in comparison with longer term training enhancements to the concentric phase performance.
authors.affiliation: Neuromuscular & Biomechanics Laboratory, Department of Health, Leisure & Exercise Science, Appalachian State University, Boone, North Carolina.
authors.forename: Kevin N
authors.initials: KN
authors.lastname: Kijowksi
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Capps
authors.forename: Courtney L
authors.initials: CL
authors.lastname: Goodman
authors.forename: Travis M
authors.initials: TM
authors.lastname: Erickson
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Knorr
authors.forename: N Travis
authors.initials: NT
authors.lastname: Triplett
authors.forename: Olumide O
authors.initials: OO
authors.lastname: Awelewa
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: McBride
mesh_terms: D000293:Adolescent; D000328:Adult; D005080:Exercise Test; D006801:Humans; D007700:Kinetics; D008297:Male; D009068:Movement; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D059385:Plyometric Exercise / Q000379:methods*; D055070:Resistance Training / Q000379:methods*; D013997:Time Factors; D055815:Young Adult