Effects of Eccentric Contraction Duration on Muscle Strength, Power Production, Vertical Jump and Soreness
type: CreativeWork
description: Prior research has investigated the effects of either eccentric-only training or comparing eccentric and concentric exercise on changes related to strength and power expression, but no research to date has investigated the impact of altering the duration of either the concentric or eccentric component on these parameters. Therefore, the purpose of this study was to assess the duration of eccentric (i.e. 2-second, 4-second vs. 6-second) muscle contractions and their effect on muscle strength, power production, vertical jump and soreness using a plate-loaded barbell Smith squat exercise. Thirty college-aged males (23 ± 3.5 years, 178 ± 6.8 cm, 82 ± 12 kg and 11.6 ± 5.1 % fat) with 3.0 ± 1.0 years of resistance training experience and training frequency of 4.3 ± 0.9 days per week were randomized and assigned to one of three eccentric training groups that incorporated different patterns of contraction. For every repetition, all three groups utilized two-second concentric contractions and paused for one second between the concentric and eccentric phases. The control group (2S) utilized two-second-eccentric contractions while the 4S group performed four-second eccentric contractions and the 6S performed six-second eccentric contractions. All repetitions were completed using the barbell Smith squat exercise. All participants completed a four-week training protocol that required them to complete two workouts per week using their prescribed contraction routine for 4 sets of 6 repetitions at an intensity of 80 — 85% 1RM. Two-way mixed factorial ANOVA were used to determine changes among groups. A p-value of 0.05 was used for all statistical determinations. At baseline, no between-group differences (p > 0.05) were found for any anthropometric, 1RM or dietary data with the exception of absolute protein intake (p = 0.03). For all performance data, significant group x time interaction effects were found for average power production across all three sets of a squat jump protocol (…
abstract: Prior research has investigated the effects of either eccentric-only training or comparing eccentric and concentric exercise on changes related to strength and power expression, but no research to date has investigated the impact of altering the duration of either the concentric or eccentric component on these parameters. Therefore, the purpose of this study was to assess the duration of eccentric (i.e. 2-second, 4-second vs. 6-second) muscle contractions and their effect on muscle strength, power production, vertical jump and soreness using a plate-loaded barbell Smith squat exercise. Thirty college-aged males (23 ± 3.5 years, 178 ± 6.8 cm, 82 ± 12 kg and 11.6 ± 5.1 % fat) with 3.0 ± 1.0 years of resistance training experience and training frequency of 4.3 ± 0.9 days per week were randomized and assigned to one of three eccentric training groups that incorporated different patterns of contraction. For every repetition, all three groups utilized two-second concentric contractions and paused for one second between the concentric and eccentric phases. The control group (2S) utilized two-second-eccentric contractions while the 4S group performed four-second eccentric contractions and the 6S performed six-second eccentric contractions. All repetitions were completed using the barbell Smith squat exercise. All participants completed a four-week training protocol that required them to complete two workouts per week using their prescribed contraction routine for 4 sets of 6 repetitions at an intensity of 80 — 85% 1RM. Two-way mixed factorial ANOVA were used to determine changes among groups. A p-value of 0.05 was used for all statistical determinations. At baseline, no between-group differences (p > 0.05) were found for any anthropometric, 1RM or dietary data with the exception of absolute protein intake (p = 0.03). For all performance data, significant group x time interaction effects were found for average power production across all three sets of a squat jump protocol (…
author: Mike, Jonathan N.
language: English
keywords: Eccentrics, Health and Physical Education
date published: 2015-09-01T07:00:00Z
date modified: 2026-07-24T05:26:22Z
provider: University of New Mexico
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of New Mexico

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1928/30403