The effects of whole-body vibration on EMG activity of the lower body muscles in supine static bridge position.

OBJECTIVES: The purpose of the current study was to firstly examine the effects of different whole-body vibration (WBV) frequencies in the lower-body muscles when applied simultaneously during a bridge exercise. Secondly, determine if there were any sex differences in the lower-body muscles of WBV during the bridge. METHODS: Seven females and 7 males completed 2 familiarization and 1 test sessions. In the test session participants were randomized to complete one 30 s bout of a bridge exercise for 3 separate conditions followed by 3-min of rest. The 3 conditions (a) No-WBV (without WBV); (b) WBV-30 (30 Hz, low amplitude); (c) WBV-50 (50 Hz, low amplitude) were performed on a WBV platform. Muscle activity of the biceps femoris (BF), semitendinosus (ST), gluteus maximus (Gmax), multifidus muscle (MF) muscles were measured. RESULTS: Muscle activity was increased with WBV in the BF and ST muscles at WBV-30 and WBV-50 conditions (p<0.05) vs. no-WBV. During No-WBV and WBV-50 conditions, males had a higher biceps femoris activity compared to females for (p<0.05) 45 and 27 %, respectively; however, during all conditions females had a high level of Gmax activity (57%) than males (p<0.05). CONCLUSION: Additional vibration at 30 and 50 Hz during the bridge exercise could be a useful method to enhance hamstring muscle activity.

Acute effect of whole-body vibration on electromechanical delay and vertical jump performance.

OBJECTIVES: To determine if a change in vertical jump performance from acute whole-body vibration can be explained by indirectly assessing spindle sensitivity from electromechanical delay. METHODS: Using a counter-balanced design, twenty college-aged participants performed whole-body vibration (WBV) and control treatments. WBV included 10 intervals (26 Hz, 3.6 mm) of 60 s in a half-squat followed by 60 s of rest. After 5 intervals, participants rested for 6-minutes before commencing the final 5 intervals. For the control, the exact same protocol of whole-body vibration was performed but without vibration. Electromechanical delay and vertical jump were assessed at baseline, during the 6-minute rest period and immediately after whole-body vibration and control. RESULTS: There were no differences between treatments, for both electromechanical delay (F(2, 38)=1.385, p=0.263) and vertical jump (F(2, 38)=0.040, p<0.96). Whole-body vibration had no effect on vertical jump performance. CONCLUSION: The current whole-body vibration protocol is not effective for acute vertical jump or electromechanical delay enhancement. Also, since there was no effect on electromechanical delay, this suggests that whole-body vibration did not enhance muscle spindle sensitivity for the parameters examined.

Using Sprint Velocity Decrement to Enhance Acute Sprint Performance.

ABSTRACT: Cochrane, DJ and Monaghan, D. Using sprint velocity decrement to enhance acute sprint performance. J Strength Cond Res 35(2): 442-448, 2021-Acute sled towing has the capability to elicit a potentiation. Currently, sled loading is determined from body mass (BM) percent. However, it may be more relevant to use a percentage of maximal sprint reduction to determine an individual's load. The purpose of this study was to determine if individualizing sled loads at 35 and 55% reduction in velocity would improve 20-m sprint performance. In addition, electromyography (EMG) was assessed to determine if any sprint-related improvements in velocity were due to changes in neural excitation. Twelve senior club male rugby union players performed familiarization and 2 sled towing sessions using a randomized, cross-over, and counterbalanced design. Testing sessions involved: baseline unresisted 20-m sprints, resisted sprint (35 and 55% reduction in velocity), and unresisted 20-m sprints at 2, 4, 6, 8, 12, and 16 minutes. The sled load to reduce maximal velocity by 35% significantly improved 20-m velocity (p <0.05, effect size [ES] = 0.21) compared with the heavier sled load (55% reduction in maximum velocity). A significant decline in sprint velocity occurred at 12 minutes (p < 0.01, ES = -0.61) and 16 minutes (p < 0.01, ES = -0.45) compared with baseline velocity. Other time intervals reported trivial small nonsignificant changes in sprint velocity (p >0.05). There was no significant change in EMG. Reducing sprint velocity provides an alternate method to determining sprint loading. Nonetheless, a greater range of reduced sprint velocity is required to assess if it is more effective than using BM percent procedure.

Peak Power Output and Onset of Muscle Activation During High Pull Exercise.

ABSTRACT: Barnes, MJ, Petterson, A, and Cochrane, DJ. Peak power output and onset of muscle activation during high pull exercise. J Strength Cond Res 35(3): 675-679, 2021-The aim of this study was to determine the percentage of 1 repetition maximum (1RM) at which peak power output occurred during the high pull (HP) exercise. In addition, the onset time of the biceps femoris (BF) and gluteus maximus (GM), across a range of loads, was investigated. Twelve resistance-trained men performed 1RM testing for the HP followed by lifts at 10% increments from 30 to 80% 1RM. During each load of power, output was measured using a linear potentiometer, whereas surface electromyography was recorded from the BF and GM. Peak power output occurred at 70% (1881.9 ± 296.1 W); however, there was no significant difference between loads at 60-80% (all p > 0.05). Loads between 40 and 80% 1RM produced significantly higher power outputs than 30% while 80% generated greater power than 100% 1RM (all p < 0.05). There was no significant (p > 0.05) main effect of muscle or load in the onset of BF (156.5-212.1 ms) or GM (112.1-158.1 ms). Therefore, these results suggest that training at a load between 60 and 80% 1RM may be useful in increasing power in the HP. In addition, activation of 2 of the hip extensors occurs in a relatively synchronous order irrespective of load.

Individual Responses to Different Vibration Frequencies Identified by Electromyography and Dynamometry in Different Types of Vibration Application.

ABSTRACT: Oliveira, MP, Menzel, H-JK, Cochrane, DJ, Drummond, MD, Demicheli, C, Lage, G, and Couto, BP. Individual responses to different vibration frequencies identified by electromyography and dynamometry in different types of vibration application. J Strength Cond Res 35(6): 1748-1759, 2021-The application of mechanical vibration is a common neuromuscular training technique used in sports training programs to generate acute increases in muscle strength. The principal aim of the study was to compare the individual optimal vibration frequency (IOVF) identified by electromyography (EMG) activity and force production in strength training. Twenty well-trained male volunteers (age: 23.8 ± 3.3 years) performed a familiarization and 2 interventions sessions, which included 5 maximal voluntary contractions (MVCs) of the elbow flexors with a duration of 10 seconds and 5-minute intervals between each MVC. The first MVC was performed without vibration followed by 4 randomized MVCs with application of vibration in the direction of the resultant muscle forces' vector (VDF) or whole-body vibration (WBV) at frequencies of 10, 20, 30, or 40 Hz. The mechanical vibration stimulus was superimposed during the MVC. Individual optimal vibration frequency, as identified by EMG, did not coincide with IOVF identified by force production; low agreement was observed between the vibration frequencies in generating the higher EMG activity, maximal force, and root mean square of force. These findings suggest that the magnitude of the vibratory stimulus response is individualized. Therefore, if the aim is to use acute vibration in conjunction with strength training, a preliminary vibration exposure should be conducted to determine the individualized vibratory stimulus of the subject, so that training effects can be optimized.

An exploratory study of vibration therapy on muscle function in patients with peripheral artery disease.

OBJECTIVE: The purpose of this exploratory study was to determine whether a single session of vibration therapy (VT) would improve muscular and functional performance in individuals with symptomatic peripheral artery disease (PAD). METHODS: In a randomized, balanced cross-over design fourteen PAD participants with intermittent claudication (mean ± standard deviation; age, 73.9 ± 4.6 years; height, 172.6 ± 68.4 cm; body mass, 85.2 ± 15.7 kg) performed VT and control that involved repeated chair rises, timed up-and-go test, and 6-minute walk test. Each intervention was separated by at least 2 days. Wearable VT devices were positioned on the right and left lower limbs that were turned on during functional testing but were turned off for the control intervention. RESULTS: VT significantly improved (P < .05) repeated chair rises and timed up-and-go test compared with control with a small effect size of 0.46 and 0.45, respectively. Similarly, a significant (P < .01) and meaningful change in 6-minute walk test was noted in VT compared with control. CONCLUSIONS: This exploratory study suggest that VT may enhance functional strength, mobility, and walking performance by extending the onset of claudication and increasing walking distance in PAD with intermittent claudication. However, further study is required to confirm and extend these preliminary findings and determine the potential mechanisms of action in VT.

Can Backward Sled Towing Potentiate Sprint Performance?

Monaghan, DJ and Cochrane, DJ. Can backward sled towing potentiate sprint performance? J Strength Cond Res 34(2): 345-354, 2020-The objectives of this study were to determine whether backward sled towing can elicit a postactivation potentiation response to enhance forward 5-m sprint performance and to determine whether sled loading through a reduction in velocity can elicit an improvement in 5-m sprint performance. A randomized design was used to examine the effects of forward and backward sled tow loading of 35 and 55% reduction of individual's maximal velocity (rVelmean) on 5-m sprint performance. Eighteen well-trained male subjects performed 4 intervention sessions (55% rVelmean backward; 55% rVelmean forward; 35% rVelmean backward; and 35% rVelmean forward) separated by a minimum of 24 hours. Intervention sessions included baseline unresisted 5-m sprints, followed by 3 loaded sled tows over a distance of 3.2 m or 5 m for heavy and light loads, respectively. An unresisted 5-m sprint was completed after 6 and 12 minutes of rest. Mean sprint velocity, electromyography, sprint kinematic, and temporal data were collected during each session. Sled towing, irrespective of load or rest period, produced no significant change in 5-m sprint velocity (p > 0.05). In addition, there were no significant changes in electromyography, kinetic, and temporal data; however, current findings support previous research of confirming muscle activation and vertical force production during sprint acceleration. It is unclear whether individualizing a reduction in velocity is a superior method to percent body mass for optimizing sled loading in well-trained male subjects.

The inclusion of vibration therapy in rehabilitating a gastrocnemius tear: a case study in master athlete.

[Purpose] The aim of this case study was to determine if VT could be included into a rehabilitation programme by monitoring the progress of muscle pain, range of motion and muscle strength. [Participant and Methods] An international male master hockey player sustained a medial gastrocnemius 5 cm tear prior to the World Cup. VT was applied early in the rehabilitation programme where 9 sessions of VT were performed during the first 16 days. Other conventional rehabilitative exercises were included. [Results] Twenty-eight days post-injury the athlete returned to full playing. Calf pain had subsided by day 8 with a change of 12° in ankle dorsi flexion range of motion. Grade 5 calf strength was attained by day 16, which was equivalent to the unaffected limb's strength. There were no residual side effects of including VT into the rehabilitation programme and it did not compromise the athlete's recovery. [Conclusion] To ensure optimal loading of VT, 9 sessions were implemented and progressively increased; consequently, there was no detrimental effect on the rehabilitative process. The athlete reported no side effects of using VT and its ease and time efficient application has a role to complementing soft tissue injury rehabilitation.

Evaluating gluteus maximus maximal voluntary isometric contractions for EMG normalization in male rugby players.

[Purpose] The aim of this study was to determine the highest electromyography (EMG) amplitude of the gluteus maximus from closed and open kinetic gluteal maximal voluntary isometric contractions (MVICs). [Participants and Methods] Ten healthy male rugby players performed three MVIC techniques that included, in random order: single leg squat, prone hip extension and standing gluteal squeeze. EMG signals were recorded from the inferior and superior regions of gluteus maximus of the dominant leg, and were normalized to the prone hip extension. [Results] For statistical analysis the EMG of both gluteus maximus regions were pooled together. The standing gluteal squeeze revealed a significantly lower EMG compared to single leg squat and prone hip extension. However, there was no significant difference in gluteal EMG activity between single leg squat and prone hip extension. [Conclusion] There is no distinct advantage for either single leg squat or prone hip extension in eliciting maximum EMG activity. Future research should compare the present positions with other MVICs that are commonly prescribed or have been demonstrated to produce high EMG amplitudes.

Cross transfer acute effects of foam rolling with vibration on ankle dorsiflexion range of motion.

INTRODUCTION: Foam roller is a device used as a massage intervention for rehabilitation and fitness performance. OBJECTIVE: To examine the effects on the ankle dorsiflexion mobility of the foam roller as well as the combination of foam roller and vibration applied to the ankle plantarflexors muscles, and to observe the possible cross-effect. METHODS: Thirty-eight undergraduate students participated in the study (19 males and 19 females). This study investigated. Three conditions (3 sets of 20 s) were performed in a randomized order (independent variables): 1) foam roller (Roller), 2) foam roller and vibration (Roller+VIB), and 3) no foam roller or vibration (Control). to determine whether of foam roller with or without vibration would benefit ankle dorsiflexion mobility. Ankle dorsiflexion ROM and plantar flexor were measured in both legs before and immediately after the treatment. RESULTS: A cross-effect was found in the non-stimulated leg. There was a significant effect on ankle mobility of Roller and Roller+VIB conditions (6% and 7%, p<0.001). CONCLUSION: Foam roller massage and vibration stimulus' foam roller massage increase ankle mobility producing a cross-effect.

The acute effect of lower-limb warm-up on muscle performance.

It has been purported that the mechanism for muscular improvement after a gluteal warm-up protocol is likely to occur from neural activation. However, little is known about whether changes in muscular performance are due to changes in muscle activity. Therefore, the aim of this study was to determine whether a lower-limb warm-up that targets the gluteal muscle group would improve countermovement jump and short-distance sprinting through increased muscle activity. Ten semi-professional rugby union players (age 25.4 ± 2.9 yr; height 1.83 ± 6.7 m; body mass 96.8 ± 10.6 kg) with at least three years of resistance training experience volunteered for the study. In a cross-over design, participants performed countermovement jumps and 5 m sprints before and after a gluteal warm-up and a 10 min rest (control). Electromyography was used to measure muscle activity of the gluteus maximus and biceps femoris. Countermovement jump height significantly improved (7.9%, p < 0.05) after the lower-limb warm-up protocol compared with the control (3.2%). There was a significant (p < 0.05) improvement in sprint times over 2.5 m and 5 m regardless of the condition. There was no significant change in the muscle activity in any of the conditions. The results indicate that a lower-limb warm-up can acutely enhance countermovement jump performance compared to a control.

Effectiveness of using wearable vibration therapy to alleviate muscle soreness.

PURPOSE: To examine the acute and short-term effect of a wearable vibration device following strenuous eccentric exercise of the elbow flexors. METHODS: Physically active males (n = 13) performed vibration therapy (VT) and control following eccentric exercise. The arms were randomised and counterbalanced, separated by 14 days. 15 min of VT (120 Hz) was applied immediately and 24, 48, and 72 h after eccentric exercise while the contralateral arm performed no VT (control). Muscle (isometric and concentric) strength, range of motion, electromyography (EMG), muscle soreness and creatine kinase were taken pre-exercise, immediately and 24, 48, and 72 h post-eccentric exercise. Additionally, the acute effect of VT of muscle strength, range of motion, EMG, muscle soreness was also investigated immediately after VT. RESULTS: In the short-term VT was able to significantly reduce the level of biceps brachii pain at 24 h (p < 0.05) and 72 h (p < 0.01), enhance pain threshold at 48 h (p < 0.01) and 72 h (p < 0.01), improve range of motion at 24 h (p < 0.05), 48 h (p < 0.01) and 72 h (p < 0.01) and significantly (p < 0.05) reduced creatine kinase at 72 h compared to control. Acutely, following VT treatment muscle pain and range of motion significantly improved (p < 0.05) at 24 h post, 48 h post, and 72 h post but no significant changes in muscle strength and EMG were reported acutely or short-term. CONCLUSIONS: Acute and short-term VT attenuated muscle soreness, creatine kinase and improved range of motion; however, there was no improvement of muscle strength recovery compared to control following eccentric exercise of the elbow flexors.

Effects of different warm-up modalities on power output during the high pull.

This study compared the effects of six warm-up modalities on peak power output (PPO) during the high-pull exercise. Nine resistance-trained males completed six trials using different warm-ups: high-pull specific (HPS), cycle, whole body vibration (WBV), cycle+HPS, WBV+HPS and a control. Intramuscular temperature (Tm) was increased by 2°C using WBV or cycling. PPO, Tm and electromyography (EMG) were recorded during each trial. Two high-pulls were performed prior to and 3 min after participants completed the warm-up. The greatest increase in PPO occurred with HPS (232.8 ± 89.7 W, P < 0.001); however, this was not different to combined warm-ups (cycle+HPS 158.6 ± 121.1 W; WBV+HPS 177.3 ± 93.3 W, P = 1.00). These modalities increased PPO to a greater extent than those that did not involve HPS (all P < 0.05). HPS took the shortest time to complete, compared to the other conditions (P < 0.05). EMG did not differ from pre to post warm-up or between modalities in any of the muscles investigated. No change in Tm occurred in warm-ups that did not include cycling or WBV. These results suggest that a movement-specific warm-up improves performance more than temperature-related warm-ups. Therefore, mechanisms other than increased muscle temperature and activation may be important for improving short-term PPO.

Does short-term gluteal activation enhance muscle performance?

A reduction in gluteus maximus (GM) strength may contribute to the etiology of musculoskeletal impairments and lower-extremity injuries. Currently, there is a paucity of evidence regarding the efficacy of implementing a short-term gluteal activation programme to improving muscle performance. Twenty four semi-professional rugby males were assigned randomly to a gluteal activation group (GLUTE) or a control group (CON). During the 6-week training intervention, the GLUTE and CON groups performed the same training, however that GLUTE group performed seven gluteal activation exercises three times weekly prior to their normal training sessions. Whilst the CON group performed the conventional training with no gluteal activation exercises. Electromyography (EMG) was measured during a maximal isometric unilateral squat (MVIC) and unilateral hip extension force from the left and right vastus lateralis, gluteus maximus, and biceps femoris. After 6 weeks of training there was no significant main or interaction effect (p > 0.05) of EMG and peak force for MVIC and hip extension between GLUTE and CON. The current gluteal activation programme did not enhance EMG activity and hip extension force therefore, the body-weight exercises may not have been sufficient to elicit the appropriate changes.

Does short-term whole-body vibration training affect arterial stiffness in chronic stroke? A preliminary study.

[Purpose] Previous studies have shown that stroke is associated with increased arterial stiffness that can be diminished by a program of physical activity. A novel exercise intervention, whole-body vibration (WBV), is reported to significantly improve arterial stiffness in healthy men and older sedentary adults. However, little is known about its efficacy in reducing arterial stiffness in chronic stroke. [Subjects and Methods] Six participants with chronic stroke were randomly assigned to 4 weeks of WBV training or control followed by cross-over after a 2-week washout period. WBV intervention consisted of 3 sessions of 5 min intermittent WBV per week for 4 weeks. Arterial stiffness (carotid arterial stiffness, pulse wave velocity [PWV], pulse and wave analysis [PWA]) were measured before/after each intervention. [Results] No significant improvements were reported with respect to carotid arterial stiffness, PWV, and PWA between WBV and control. However, carotid arterial stiffness showed a decrease over time following WBV compared to control, but this was not significant. [Conclusion] Three days/week for 4 weeks of WBV seems too short to elicit appropriate changes in arterial stiffness in chronic stroke. However, no adverse effects were reported, indicating that WBV is a safe and acceptable exercise modality for people with chronic stroke.

Vibration exercise as a warm-up modality for deadlift power output.

Vibration exercise (VbX) has gained popularity as a warm-up modality to enhance performance in golf, baseball, and sprint cycling, but little is known about the efficacy of using VbX as a warm-up before resistance exercise, such as deadlifting. The aim of this study was to compare the effects of a deadlift (DL)-specific warm-up, VbX warm-up, and Control on DL power output (PO). The DL warm-up (DL-WU) included 10, 8, and 5 repetitions performed at 30, 40, and 50% 1-repetition maximum (1RM), respectively, where the number of repetitions was matched by body-weight squats performed with vibration and without vibration (Control). The warm-up conditions were randomized and performed at least 2 days apart. Peak power (PP), mean power, rate of force development (RFD), and electromyography (EMG) were measured during the concentric phase of 2 consecutive DLs (75% 1RM) at 30 seconds and 2:30 minutes after the warm-up conditions. There was no significant (p > 0.05) main effect or interaction effect between the DL-WU, VbX warm-up, and Control for PP, mean power, RFD, and EMG. Vibration exercise warm-up did not exhibit an ergogenic effect to potentiate muscle activity more than the specific DL-WU and Control. Therefore, DL PO is affected to a similar extent, irrespective of the type of stimuli, when the warm-up is not focused on raising muscle temperature.

Muscle Activation and Onset Times of Hip Extensors during Various Loads of a Closed Kinetic Chain Exercise.

The aim of this study was to determine the muscle activity and onset time of hip extensors during a closed kinetic chain exercise (deadlift) at sub-maximal loads of 30%, 40%, 50%, and 75% of one repetition maximum (1RM). Twelve healthy males with at least three years of resistance training experience volunteered for the study. Biceps femoris (BF) and gluteus maximus (GM) muscle activity, onset time, peak and mean power were measured during the concentric phase of the deadlift. There was no main effect (p > 0.05) or no interaction effect for the onset time in BF and GM and for each load BF and GM had similar muscle activity. Increasing the external load during deadlift had no adverse effect on the relative onset time and it did not promote BF onset to occur before GM onset, thus both muscles were simultaneously activated, which should not compromise a delay in GM.

The relationship between climbing ability and physiological responses to rock climbing.

AIM: The aim of this study was to examine the relationship between submaximal and maximal physiological responses to rock climbing for climbers of differing abilities. METHODS: Twenty-six male climbers performed a submaximal climbing test on a known circuit at 90° (vertical) and 105° (15° overhanging) inclination and speed 25 movements · min(-1). A maximal test was undertaken on a similar circuit at the same speed with inclination increasing by 10° for each successive 3 min stage. RESULTS: Mean oxygen consumption and heart rate (HR) increased with wall inclination and climbers reached a mean (± SD) peak VO2 of 40.3 ± 3.5 mL · kg(-1) · min(-1) during the maximal test. Self-reported climbing ability was negatively correlated with VO2 and HR during the submaximal test at 90° (VO2, r = -0.82; HR, and r = -0.66) and at 105° (VO2, r = -0.84; HR, and r = -0.78) suggesting an increased exercise economy for climbers with a higher ability level. CONCLUSION: Findings from this study indicate that there is a relationship between wall inclination and the physiological demand of a climb. However, the increased technical ability and fitness of higher level climbers appears to an extent to offset the increased demand through improved exercise economy which in turn leads to an increased time to exhaustion and an improvement in performance.

Does acute vibration exercise enhance horizontal jump performance?

The aim of this study was to investigate the acute effect of vibration exercise (VbX) on repetitive horizontal jumping performance and to examine the duration of the rest interval between the horizontal jump sets following acute VbX. Fourteen track athlete males (age 20.8 ± 1.8 yr; height 1.80 ± 0.05 m; body mass 73.1 ± 7.5 kg) performed four conditions in a randomised order; (a) VbX with 1 min rest between repetitive horizontal jump (RHJ) sets [VbX-1min]; (b) VbX with 2 min rest between RHJ sets [VbX-2min]; (c) No VbX with 1 min rest between RHJ sets [Con-1min]; (d) No VbX with 2 min rest between RHJ sets [Con-2min]. Intermittent VbX (six 60 s exposures with 30 s rest) at 26 Hz (6 mm peak-to-peak displacement) was performed in an isometric squat position (120° of knee flexion). The mean values of distance, velocity and time taken of RHJ from the four conditions were used in repeated measures [condition (VbX and Control) and rest period (1min; and 2min)] ANOVA. There was a condition effect such that VbX significantly increased RHJ distance (p < 0.05) compared to control (no VbX). Furthermore, VbX significantly increased RHJ velocity (p < 0.05) compared to no VbX and there was an interaction effect (condition x rest) where the velocity was significantly higher in VbX-2min compared to VbX-1 min, Con-2min, and Con-1min respectively. Acute intermittent VbX has the ability to enhance repetitive horizontal jump distance and velocity, which could be used as an additional method for warm-up intervention to increase explosive power performance. Key pointsAcute intermittent VbX can enhance repetitive horizontal jump distance and velocity.Acute intermittent VbX may be used as an additional method for warm-up intervention to increase explosive power performance.

The effect of acute vibration exercise on short-distance sprinting and reactive agility.

Vibration exercise (VbX) has been a popular modality to enhancing physical performance, where various training methods and techniques have been employed to improve immediate and long-term sprint performance. However, the use of acute side-alternating VbX on sprint and agility performance remains unclear. Eight female athletes preformed side-alternating vibration exercise (VbX) and control (no VbX) in a cross over randomised design that was conducted one week apart. After performing a warm-up, the athletes undertook maximal 5m sprints and maximal reactive agility sprints (RAT), this was followed by side-alternating VbX (26 Hz, 6mm) or control (no VbX). Immediately following the intervention, post-sprint tests and RAT were performed. There was a significant treatment effect but there was no time effect (pre vs. post) or interaction effect for sprint and RAT; however, side-alternating VbX did not compromise sprint and agility performance. Key PointsAcute VbX could be beneficial for the acceleration phase (1.5m) of a short-distance sprint.Acute VbX does not have positive influence on short-distance (3m & 5m) sprint performance.Acute VbX does not enhance reactive agility performance.