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The purpose of this study is to determine the effects of coupling WBV and acute muscular fatigue to determine its effects on countermovement vertical jump (CMVJ) performance and isometric mid-thigh pull (IMTP). Twenty-eight healthy active adults volunteered for five-day study. Testing sessions 2–5 included one of four conditions: No WBV and no fatigue (CON), WBV and fatigue (WBV + FAT), WBV and no fatigue (WBV), and no WBV and fatigue (FAT). WBV was performed using a frequency of 50 Hz and a low amplitude while performing quarter squats for a total of 4 min with a 30 s rest or work ratio. Lower-body fatigue induced using Bosco fatigue protocol. CMVJ and IMTP were performed on force plates. SPSS was used to perform a 2 × 2 Repeated Measures ANOVA. Significant main effects were found for fatigue in CMVJ-height and CMVJ-peak ground reaction force, no significant main effect for WBV, and no significant interactions. Lower-body fatigue decreases vertical jump performance, and WBV did not attenuate the detrimental effects of lower-body fatigue.

Objective: The purpose of this investigation was to determine the differences in collegiate and recreationally trained soccer players in sprint, vertical jump, and balance performance. Methods: Twenty-one soccer players, twelve Division II collegiate and nine recreationally trained volunteered to participate. Session one acted as a familiarization day, where the participants were familiarized with testing day protocols. During testing day, participants performed a dynamic warm-up, followed by balance measurements, three countermovement vertical jumps, and pro-agility shuttle test. Results: There were no significant (p>0.05) differences between groups in the all balance variables. Collegiate soccer players had a significantly (p0.05) differences in groups in all other variables. Conclusion: These results indicate that collegiate, Division II, soccer players had greater vertical jumping and sprinting velocities when compared to recreationally trained soccer players. These results may have been impacted by the lack of resistance training background in either of the two groups. With the addition of more time on a collegiate resistance training program, it is very likely the Division II athletes will see a significant increase in all balance, sprint, and vertical jump performance measures compared to recreationally trained players who receive little to no specialized resistance training.

Cooper, CN, Dabbs, NC, Davis, J, and Sauls, NM. Effects of lower-body muscular fatigue on vertical jump and balance performance. J Strength Cond Res 34(10): 2903-2910, 2020-Lower-body fatigue can lead to a decline in vertical jump (VJ) and balance performance due to decreased motor control and coordination. The purpose is to determine the effects of lower-body fatigue on VJ and balance performance. Twenty-four recreationally trained individuals participated in a single 1-hour familiarization and testing session. Participants were familiarized with balance, countermovement vertical jump (CMVJ), and static vertical jump (SVJ) using the Vertec. Three trials of static and dynamic balance tests were completed. Three trials of a SVJ and CMVJ were completed in a randomized order pre/post fatigue protocol. Three trials of double-leg and single-leg tests were performed. Dependent t tests analyzed differences between pre/post fatigue protocol for jumping and balance measures. There was a significant (p0.001) difference between pre/post measures for SVJ-H (height), CMVJ-H, and CMVJ peak power (PP). Results showed an interaction (p0.05) for group by time for CMVJ-H, CMVJ-peak force (PF), SVJ-PF, and SVJ-PP. There were no main effects (p0.05) for time or group for SVJ-rate of velocity development and SVJ-impact force (IF). There were no interactions, time effects, and group effects for balance variables (p0.05). Bosco protocol decreased VJ height and PF in SVJ, and VJ height and PF, IF, peak velocity, and PP for CMVJ potentially due to decreased muscle control, coordination, and force-generating capacity after fatigue. Practitioners should consider fatiguing effects on individuals performing jumping motions but it seems that fatigue has no effect on balance.

The purpose of this study was to evaluate the effect of different rest intervals following whole-body vibration on counter-movement vertical jump performance. Sixteen females, eight recreationally trained and eight varsity athletes volunteered to participate in four testing visits separated by 24 h. Visit one acted as a familiarization visit where subjects were introduced to the counter-movement vertical jump and whole-body vibration protocols. Visits 2–4 contained 2 randomized conditions. Whole-body vibration was administered in four bouts of 30 s with 30 s rest between bouts. During whole-body vibration subjects performed a quarter squat every 5 s, simulating a counter-movement vertical jump. Whole-body vibration was followed by three counter-movement vertical jumps with five different rest intervals between the vibration exposure and jumping. For a control condition, subjects performed squats with no whole-body vibration. There was a significant (p &lt, 0.05) main effect for time for vertical jump height, peak power output, and relative ground reaction forces, where a majority of individuals max jump from all whole-body vibration conditions was greater than the control condition. There were significant (p &lt, 0.05) group differences, showing that varsity athletes had a greater vertical jump height and peak power output compared to recreationally trained females. There were no significant (p &gt, 0.05) group differences for relative ground reaction forces. Practitioners and/or strength and conditioning coaches may utilize whole-body vibration to enhance acute counter-movement vertical jump performance after identifying individuals optimal rest time in order to maximize the potentiating effects.

Jumping and balance are necessary skills for most athletes, and mini-trampoline training has been shown to improve them. Little is known about the acute effect of mini-trampoline jumping on jump performance and dynamic balance. Objectives: The purpose of this study is to investigate the effect of 6 maximal jumps on a mini-trampoline on countermovement vertical jump (CMVJ) variables and on balance parameters. Methods: Twenty one recreationally trained individuals participated in three testing sessions and were either allocated to a control group (N=10) or a trampoline group (N=11). All the participants performed a dynamic warm up prior to their assessments. Baseline CMVJ and balance assessments were measured. For the jump performance tests, the control group rested for 30s, and the trampoline group performed 6 maximal CMVJs on a mini-trampoline. Immediately following the trampoline jumps or the rest period, participants performed three jump trials. The jumping protocol was repeated every minute up to 5 minutes and balance was reassessed immediately after only. Results: There was no significant interaction of time by group and no group effects in all the jumping parameters, however, there was a significant increase in jump height (p 0.05) on the balance variables. Conclusion: These results do not support our hypothesis and show that trampoline jumping does not improve jump and balance performance acutely.

Because of the relative newness of mouthpieces, there are few investigations into using performance mouthpieces during sport and physical activity to substantiate claims of performance enhancement. The purpose of this study was to investigate the acute effect of a commercially available, noninjury preventive, performance mouthpiece on practical acute performance measures of power and strength. A within-subjects design was used to evaluate 21 (N = 21) recreationally trained college aged males on the performance of a maximum countermovement vertical jump (CMVJ) from a force platform and 1 repetition maximum (1RM) bench press exercise for the following conditions: with mouthpiece (MP) and without mouthpiece (noMP). Rate of force development (RFD) and peak vertical force (PF) were derived from force platform data. Statistical analysis revealed no significant differences between conditions for CMVJ height (p = 0.13), RFD at 200 ms (p = 0.09), PF (p = 0.08), and 1RM bench press (p = 0.45). These data indicate that the use of this particular jaw aligning mouthpiece specifically in an attempt to produce an ergogenic effect on performance is unwarranted.

Enhancing vertical jump performance is critical for many sports. Following high intensity training, individuals often experience exercise induced muscle damage (EIMD). Many recovery modalities have been tested with conflicting results. The purpose of this investigation was to determine the effect of whole-body vibration (WBV) on vertical jump performance following EIMD. 27 females volunteered for 7 sessions and were randomly assigned to a treatment or control group and administered each testing day. Vertical jump performance was assessed via vertical jump height (VJH), peak power output (PPO), rate of force development (RFD), relative ground reaction force (GRFz), and peak activation ratio of the vastus medialis (VM) via electromyography (EMG) before and after 3 days of EIMD via split squats. Two testing sets were collected each day, consisting of pre measures followed by WBV or control, and then post second measures. A 2x8 (group x time) mixed factor analysis of variance (ANOVA) was conducted for each variable. No significant interactions or group differences were found in any variable. Significant main effects for time were found in any variable, indicating performance declined following muscle damage. These results indicate that WBV does not aid in muscle recovery or vertical jump performance following EIMD.

Assessing athletic performance is vital for athletes, coaches, and scientists to identify changes in performance over time and use that information to enhance the training program. Evaluating vertical jumps is a common method used to assess expression of lower body muscular force and power, as well as serving to practically predict performance outcomes.1,2,3 Additionally, vertical jump testing is reliable and valid in its estimation of explosive muscular power,4 power development,5 and as an indicator of performance.6 Two primary jumps utilized to measure athletes’ jumping ability are the squat or static jump (SJ) and countermovement vertical jump (CMJ). The SJ assesses lower-body concentric strength and power while the CMJ can assess lower-body reactive strength and power (SSC incorporation).7 The stretch shortening cycle (SSC) is highly utilized in many sports and sporting activities in which reactive ability is necessary. Furthermore, the more efficient the SSC, the better the rates of force development (RFD),8 which itself is an important determinant of athletic performance. The literature examining the physical characteristics of athletes is abundant. However, the need still exists for data investigating the relationship and predictive nature of anthropometric characteristics to athletic characteristics. Relationships of female athletes’ body composition to their athletic performance is especially important as they have a greater propensity for injury (lower limb ligamentous injuries, stress fractures, etc.) compared to their male counterparts,9,10,11 with poor body composition and the resultant power-to-weight ratio decrease as a possible culprit. However, this can be obviated by identifying discrepancies and altering the training (if necessary) to benefit the athlete (increased strength, lean body mass and decreased fat mass).12 Therefore, the purpose of this work was to determine the relationships between specific measurements of body composition and performance over a variety of vertical jumps in collegiate female athletes. The authors hypothesized that athletes with greater percentage of bone-free lean tissue mass will be better jumpers and that body composition will be a strong predictor of jumping ability. Additionally, athletes with greater reliance on jumping during competition and training are hypothesized to be the better jumpers.

Vertical jumping ability is a critical skill for success in many sports. Previous studies have reported conflicting results on the effects of heavy-load, light-load, contrast, or plyometric training to improve vertical jump height. A novel jump training method, using assistance via elastic cords or an absolute weight, has received little attention. These studies, using an overspeed paradigm, support assistance as an effective training method compared with free or overload jump training. However, there is a lack of investigation and standardization related to the critical assisted jump training variables of frequency, intensity (assistance level), volume, and rest. Therefore, the purpose of this review was to provide an overview of assisted jump training, associated variables, and potential benefits to enhance vertical jump height.

Tran, TT, Brown, LE, Coburn, JW, Lynn, SK, Dabbs, NC, Schick, MK, Schick, EE, Khamoui, AV, Uribe, BP, and Noffal, GJ. Effects of different elastic cord assistance levels on vertical jump. J Strength Cond Res 25(12): 3472-3478, 2011-Currently, little research has been conducted using body weight reduction (BWR) as a means to enhance vertical jump. The purpose of this study was to determine the effects of different elastic cord assistance levels on vertical jump height (JH), takeoff velocity (TOV), relative ground reaction force (rGRF), relative impact force (RIF), and descent velocity (DV). Thirty recreationally trained college men and women (M = 15, W = 15) completed 3 testing sessions consisting of 5 conditions: 0, 10, 20, 30, and 40% BWR. In all BWR conditions, the subjects wore a full body harness while being attached to 2 elastic cords suspended from the ceiling and a linear velocity transducer. They then performed 3 maximal countermovement jumps with arm swing on a force plate. The results indicated no interaction of condition by sex for any variable; however, there was a significant (p0.05) main effect for condition for each variable. The JH significantly increased across all conditions (0%: 43.73 ± 1.62 cm, 40%: 64.77 ± 2.36 cm). The TOV at 30% (2.73 ± 0.34 m·s) was significantly greater than that at 0% (2.59 ± 0.39 m·s) and 10% (2.63 ± 0.34 m·s), whereas that at 40% (2.79 ± 0.43 m·s) was significantly greater than that at0, 10, and 20%. The rGRF at 30% (18.62 ± 4.35 N·kg) was significantly greater than that at0, 10, and 20%, whereas that at 40% (21.38 ± 5.21 N·kg) was significantly greater than in all conditions. The RIF at 20, 30, and 40% (40%: 61.60 ± 18.53 N·kg) was significantly greater than that at 0% (44.46 ± 9.12 N·kg). The DV at 20% (2.61 ± 0.31 m·s) was significantly greater than at 10%, whereas those at 30 and 40% (2.8 ± 0.41 m·s) were significantly greater than at 0, 10, and 20%. These results demonstrate that using different elastic cord levels to reduce body weight appears effective for increasing ascent and descent force and velocity variables. Future research should investigate greater BWR% and chronic training.

Whole-body vibration (WBV) may potentiate vertical jump (VJ) performance via augmented muscular strength and motor function. The purpose of this study was to evaluate the effect of different rest intervals after WBV on VJ performance. Thirty recreationally trained subjects (15 men and 15 women) volunteered to participate in 4 testing visits separated by 24 hours. Visit 1 acted as a familiarization visit where subjects were introduced to the VJ and WBV protocols. Visits 2-4 contained 2 randomized conditions per visit with a 10-minute rest period between conditions. The WBV was administered on a pivotal platform with a frequency of 30 Hz and an amplitude of 6.5 mm in 4 bouts of 30 seconds for a total of 2 minutes with 30 seconds of rest between bouts. During WBV, subjects performed a quarter squat every 5 seconds, simulating a countermovement jump (CMJ). Whole-body vibration was followed by 3 CMJs with 5 different rest intervals: immediate, 30 seconds, 1 minute, 2 minutes, or 4 minutes. For a control condition, subjects performed squats with no WBV. There were no significant (p > 0.05) differences in peak velocity or relative ground reaction force after WBV rest intervals. However, results of VJ height revealed that maximum values, regardless of rest interval (56.93 ± 13.98 cm), were significantly (p < 0.05) greater than the control condition (54.44 ± 13.74 cm). Therefore, subjects' VJ height potentiated at different times after WBV suggesting strong individual differences in optimal rest interval. Coaches may use WBV to enhance acute VJ performance but should first identify each individual's optimal rest time to maximize the potentiating effects.