The purpose of this study was to determine the effects of a post activation potentiation (PAP) warm-up on sprint speed, with an emphasis on the role of specificity regarding the preparatory conditioning activity. It was hypothesized that a unilateral conditioning activity (barbell lunge) would provide a greater PAP effect on short sprint ability then a bilateral conditioning activity (barbell back squat). Sixteen NCAA Track Athletes participated (7 males, 9 females) in the study. The experiment employed a repeated measures crossover design where, following a familiarization session, each subject completed a randomly assigned warm-up (WU) on three different days with at least 48 hours between sessions. Following the randomly assigned WU, sprint speed was tested over a distance of 36.6 meters as well as quartiles. The WU's were: a dynamic, a dynamic followed by a unilateral barbell lunge (BL), and a dynamic followed by a bilateral back squat (BS). A repeated measures ANOVA was utilized to determine if there were significant differences between sprint times for each WU strategy. There were no statistically significant differences in sprint times between WU conditions at 36.6 m or any quartile (p>0.05). Within the parameters of this study, neither an intense bilateral or unilateral conditioning activity improved short sprint performance beyond that of a dynamic WU activity.

The purposes of this dissertation were to examine bilateral asymmetry as a factor of postactivation potentiation, examine and compare the acute effects of ballistic and non-ballistic concentric-only half-squats on squat jump performance, and compare the potentiation and temporal profiles of strong and weak subjects following potentiation protocols that included ballistic and non-ballistic concentric-only half-squats. The following are major findings of the dissertation. Squat jump performance may be acutely enhanced following ballistic concentric-only half-squats; however the changes in performance do not appear to be related to bilateral symmetry. Ballistic concentric-only half-squats acutely improve various squat jump performance variables at various time intervals; however the changes in performance are not related to the bilateral symmetry of the subject. Ballistic concentric-only half-squats produced superior acute potentiation effects with regard to jump height, peak power, an...

The purpose of this study was to compare acute countermovement jump (CMJ) responses after functional isometric (FI) and dynamic half (DH) squats. Ten strength-trained males (relative full back squat 1 repetition maximum [1RM]: 1.9 ± 0.2) participated in a randomized crossover design study. On 2 separate days, participants performed baseline CMJs followed by either FI or DH squats loaded with 150% of full back squat 1RM. Further CMJs were performed between 2 and 11 minutes after FI or DH squats. Kinematic and kinetic CMJ variables were measured. There were no differences observed between conditions when peak CMJ variables after FI or DH squats were compared with baseline values (p > 0.05). Countermovement jump time effects (p ≤ 0.05) were observed after squats. Increases in peak force (p ≤ 0.05; FI: 3.9%, range: -0.9 to 9.1%; DH: 4.2%, range: 0.0-11.5%) and decreases in peak power (p ≤ 0.05; FI: -0.4%, range: -5.1 to 4.0%; DH: -1.1%, range: -6.6 to 2.9%) occurred for combined cond...

Abstract One of the most widely used Olympic weightlifting derivatives, hang snatch and clean, is believed to be one of the most effective ways to improve the performance of athletes in sports that require power, strength, and speed. This study was conducted to investigate the effects of split-style hang snatch, and clean and jerk training (twice a week for 6 wk) on leg stiffness, vertical jump, agility, and sprint performance in volleyball players. The participants (n=34 collegiate female volleyball players) were randomized into training (n=17, age=15.63±1.3 years, height=166.05±5.7 cm, body weight=63.45±2.97 kg) and control groups (n=17, age=15.23±1.83 years, height=167.46±5.69 cm, body weight=60.46±4.14 kg). The variables included spike jump, counter movement jump, time to 5-m sprint and 20-m sprint, change of direction, and leg stiffness. The effects of split-style hang snatch and clean and jerk training on the measured variables were assessed by magnitude-based inferences. Generally, the increases in the measured variables were higher in the training group. The probability of an increase in leg stiffness was very likely (precision, 98.9%, d=0.722); 5-m sprint increase very likely (99.7%, d=−1.544); 20-m sprint increase very likely (99.9%, d=−0.774); and the probability of increase in change of direction was found to be likely, (85.4%, d=−0.385). The increases in countermovement jump were insignificant. We conclude that split hang snatch and clean and jerk exercises improve leg stiffness, spike jump, time to 5-m and 20-m sprint, and change of direction in female volleyball players. Keywords Olympic Weightlifting, Weightlifting, Snatch and Clean, Stiffness, Vertical Jump

Background: Back squats (BSQ) have been shown to transiently improve performance in explosive vertical movements such as the vertical jump (VJ). Still, understanding of this phenomenon, termed post-activation potentiation (PAP), remains nebulous as it relates to explosive horizontal movements. Objective: Therefore, the purpose of the present investigation was to assess whether heavy BSQ can potentiate both VJ and horizontal jump (HJ) performance. Method: Nine male ice hockey players from the Long Beach State ice hockey team performed five testing sessions separated by 96-hours. The first testing session consisted of a one repetition maximum (1-RM) BSQ to determine subsequent testing loads. The four subsequent testing sessions, which were randomized for order, consisted of five repetitions of BSQ at 87% 1-RM followed by horizontal jump (BSQ-HJ), five repetitions of BSQ at 87% 1-RM followed by vertical jump (BSQ-VJ), horizontal jump only (CT-HJ) and vertical jump only (CT-VJ). During the potentiated conditions, rest intervals were set at five minutes between the BSQ and either VJ or HJ. Alpha-level was set a priori at 0.05. Results: The results indicate that both vertical (p=0.017) and horizontal (p=0.003) jump were significantly increased (VJ= +5.51cm, HJ= +11.55cm) following a BSQ. Conclusion: These findings suggest that BSQ may improve both vertical and horizontal jump performance in athletes who participate in sports emphasizing horizontal power, such as ice hockey.

This review article discusses previous postactivation potentiation (PAP) literature and provides a deterministic model for vertical jump (i.e., squat jump, countermovement jump, and drop/depth jump) potentiation. There are a number of factors that must be considered when designing an effective strength-power potentiation complex (SPPC) focused on vertical jump potentiation. Sport scientists and practitioners must consider the characteristics of the subject being tested and the design of the SPPC itself. Subject characteristics that must be considered when designing an SPPC focused on vertical jump potentiation include the individual's relative strength, sex, muscle characteristics, neuromuscular characteristics, current fatigue state, and training background. Aspects of the SPPC that must be considered for vertical jump potentiation include the potentiating exercise, level and rate of muscle activation, volume load completed, the ballistic or non-ballistic nature of the potentiating exercise, and the rest interval(s) used following the potentiating exercise. Sport scientists and practitioners should design and seek SPPCs that are practical in nature regarding the equipment needed and the rest interval required for a potentiated performance. If practitioners would like to incorporate PAP as a training tool, they must take the athlete training time restrictions into account as a number of previous SPPCs have been shown to require long rest periods before potentiation can be realized. Thus, practitioners should seek SPPCs that may be effectively implemented in training and that do not require excessive rest intervals that may take away from valuable training time. Practitioners may decrease the necessary time needed to realize potentiation by improving their subject's relative strength.

This review discusses previous literature that has examined the influence of muscular strength on various factors associated with athletic performance and the benefits of achieving greater muscular strength. Greater muscular strength is strongly associated with improved force-time characteristics that contribute to an athlete's overall performance. Much research supports the notion that greater muscular strength can enhance the ability to perform general sport skills such as jumping, sprinting, and change of direction tasks. Further research indicates that stronger athletes produce superior performances during sport specific tasks. Greater muscular strength allows an individual to potentiate earlier and to a greater extent, but also decreases the risk of injury. Sport scientists and practitioners may monitor an individual's strength characteristics using isometric, dynamic, and reactive strength tests and variables. Relative strength may be classified into strength deficit, ...

Grip strength has been shown to be closely linked to body strength in mature-aged adults. However what may be of greater importance is the relationship between grip strength and functional movements in aging adults. Purpose: This study examined the relationship between grip strength and functional body movements in mature-aged adults. Methods: Female (n=12, age=71.2±3.8 years, mass=66.3±9.2 kg) and male (n=16, age=72.9±4.7 years, mass=85.5±9.4 kg) participants completed functional body movements including: vertical jump (VJ), medicine ball (MB) throws (1.5, 3.0, & 5.0 Kgs), and a stair climb (SC) test. Likewise, all participants performed maximal handgrip (MG) with the Jamar handgrip dynamometer. Pearson correlation coefficients (PCC) were then calculated to determine the relationship between dominant hand MG and the functional body movement scores. Results: PCC’s were as follows: MG-VJ (r=0.62), MG-MB1.5 (r=0.86), MG-MB3.0 (r=0.87), MG-MB5.0 (r=0.91), and MG-SC (r=0.79). All PCC’s ...