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Date Permissions Signed


Date of Award


Document Type

Masters Thesis

Degree Name

Master of Education (MEd)


Health and Human Development

First Advisor

Brilla, Lorraine R., 1955-

Second Advisor

Suprak, David N. (David Nathan)

Third Advisor

Chalmers, Gordon R.


The purpose of this study was to examine the acute effect of a high-intensity isometric potentiating warm-up on subsequent maximal horizontal bat velocity in experienced female softball players (n = 28). The isometric potentiating warm-up consisted of 3 sets of 5-second maximal voluntary contractions held in the early swing phase, pulling against an immovable device. The warm-up was designed to acutely enhance muscle performance by inducing post-activation potentiation (PAP), ultimately eliciting an increase in bat velocity. Because optimal recovery duration following a potentiating warm-up can be highly variable, swing trials were conducted at pre-determined rest intervals (1, 2, 4, 6, 8, 10, and 12 minutes) to identify the recovery time which may have allowed for maximal possible benefits. Bat velocity was measured immediately prior to bat-ball impact. The results indicate that the phase specific isometric warm-up elicited increased bat velocity at 2, 4, 6, 8, 10, and 12 minutes. Statistical analysis was carried out using a one-way repeated measures analysis of variance (ANOVA) and showed that maximal horizontal bat velocity was significantly enhanced 6 minutes following the isometric warm-up protocol (+1.27 m/s, +2.84 mph, +4.93%; p < 0.05). Additionally, a significant quadratic trend was observed, with bat velocity peaking at six minutes and subsequently decreasing (p < 0.05). No correlation was found between baseline measures of absolute (ABS) and relative (REL) strength and the amount of potentiation that occurred. The positive effect of the potentiating warm-up protocol is similar to what has been reported in the literature regarding PAP and explosive performance.





Western Washington University

OCLC Number


Subject – LCSH

Batting (Softball)--Physiological aspects; Isometric exercise; Human mechanics; Softball--Training




masters theses




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