Dissertations and Theses @ UNI


Thesis (UNI Access Only)


Stretching exercises--Physiological aspects; Baseball--Training--Iowa--Iowa City; Track and field--Training--Iowa--Iowa City; University of Iowa--Baseball--Training; University of Iowa--Track and field--Training;


Muscle performance depends on the balance of postactivation potentiation (PAP) and fatigue. Although research has shown countermovment vertical jump (CMJ) to be positively affected by PAP, little data exist with the use of more realistice pre-stimulus modalities. The aim of the present study was to investigate the effects of an isometric pre-performance stimulus paired with a dynamic stretching (DS) routine, on vertical jump displacment (VJD, m), mean velocity (MV, m/s) and peak velocity (PV, m/s). Fifteen male, Division I baseball and track and field athletes, with at least one year of previous training under a certified strength and conditioning specialist, currently active in a structured collegiate strength and conditioning program, and having had no prior chronic lower limb injuries, were used to evaluate PAP. A cross-over repeated measure design consisting of three testing session was utilized. A five minute cycling warm-up was followed by a DS routine (DS), DS routine plus two isometric clean pulls (DS+PAP), or 10 minutes of cycling (control). Each conditioned was paired with 3 CMJs at one minute post cycling warm-up, 30seconds following the experimental stimulus, and eight minutes post stimulus. VJD, MV and PV were recorded for each trial. The data collected in this study suggest that DS as well as DS+PAP both failed to influence CMJ MV and PV but did enhance VJD compared to the control. There was no difference between DS and DS+PAP. The research supports the usage of the dynamic warm-up to prepare athletes for lower body explosive movements such as jumping, but displays no evidence to support the addition of PAP to a warm-up routine.

Year of Submission


Degree Name

Master of Arts


School of Health, Physical Education, and Leisure Services


Division of Physical Education

First Advisor

Robin Lund

Date Original


Object Description

1 PDF file (vi, 67 pages)



File Format


Off-Campus Download