Acute Effects of Eccentric Overload on Concentric Front Squat Performance

• Autores: Cameron N. Munger, David C. Archer, Whitney D. Leyva, Megan A. Wong, Jared W. Coburn, Pablo B. Costa, Lee E. Brown
• Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 31, Nº. 5, 2017, págs. 1192-1197
• Idioma: inglés
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• Resumen

  • Eccentric overload is used to enhance performance. The purpose of this study was to investigate the acute effects of eccentric overload on concentric front squat performance. Twenty resistance-trained men (age = 23.80 ± 1.82 years, height = 176.95 ± 5.21 cm, mass = 83.49 ± 10.43 kg, 1 repetition maximum [1RM] front squat = 131.02 ± 21.32 kg) volunteered. A dynamic warm-up and warm-up sets of front squat were performed. Eccentric hooks were added to the barbell. They descended for 3 seconds, until eccentric hooks released, and performed the concentric phase as fast as possible. There were 3 randomly ordered conditions with the concentric phase always at 90% 1RM and the eccentric phase at 105, 110, and 120% of 1RM. Two repetitions were performed for each condition. A repeated measures analysis of variance was used to determine differences. For peak velocity, there were main effects for time and condition (p < 0.05), where post (1.01 ± 0.10 m·s-1) was greater than pre (0.96 ± 0.11 m·s-1) and 120% (1.03 ± 1.11 m·s-1) was greater than 105% (0.99 ± 0.13 m·s-1). For peak power, there was a main effect for condition where 120% (2,225.00 ± 432.37 W) was greater than 105% (2,021.84 ± 563.53 W). For peak ground reaction force, there were main effects for time and condition, where post was greater than pre and 120% was greater than 105%. For the rate of force development, there was no interaction or main effects. Eccentric overload enhanced concentric velocity and power; therefore, it can be used by strength coaches and athletes during the power phase of a training program. It can also be used to prescribe supramaximal loads and could be a tool to supplement the clean exercise because the front squat is a precursor.