Darryl J. Cochrane

Acute whole body vibration training increases vertical jump and flexibility performance in elite female field hockey players

Objective: To quantify the acute effect of whole body vibration (WBV) training on arm countermovement vertical jump (ACMVJ), grip strength, and flexibility performance. Methods: Eighteen female elite field hockey players each completed three interventions of WBV, control, and cycling in a balanced random manner. WBV was performed on a Galileo machine (26 Hz) with six different exercises being performed. For the control, the same six exercises were performed at 0 Hz, whilst cycling was performed at 50 W. Each intervention was 5 min in duration with ACMVJ, grip strength, and flexibility measurements being conducted pre and post intervention. Results: There was a positive interaction effect (intervention×pre-post) of enhanced ACMVJ (p<0.001) and flexibility (p<0.05) parameters following WBV; however no changes were observed after the control and cycling interventions. There was no interaction effect for grip strength following the three interventions. Conclusions: Acute WBV causes neural potentiation of the stretch reflex loop as shown by the improved ACMVJ and flexibility performance. Additionally, muscle groups less proportionally exposed to vibration do not exhibit physiological changes that potentiate muscular performance.

The potential neural mechanisms of acute indirect vibration.

The aim of this review was to examine the physiological effects of vibration exercise (VbX), including the cardiovascular indices and to elucidate its potential use for those with compromised health. VbX has long been acknowledged as a potential modality in sport, exercise, and health sectors. Muscle force and power have been shown to increase after VbX for athletes, the aged and those with diseases, where neural factors are thought to be the main contributor. Further, similarities to the tonic vibration reflex have been used to propose that the muscle spindle plays a role in activating the muscle which could benefit those with compromised health. There is strong evidence that acute VbX can enhance upper and lower-body muscle power, and there is some indication that longer-term VbX can augment muscle power of upper and lower body extremities, although this is less convincing. It is not conclusive whether VbX increases force attributes. This has been fraught by the type and parameters used for various muscle contractions, and the different sample populations that have varied in chronological age, experience and training status. VbX provides an insufficient stimulus to enhance cardiovascular indices, where VbX cannot increase heart rate to the same extent as conventional aerobic exercise. But when conventional aerobic exercise is not possible, for example, in aged, cardiovascular compromised persons, VbX could be implemented at an early stage because it could provide a safe induction of a slight elevation of cardiovascular function indices while providing neural and myogenic benefits. In conclusion, VbX is a safe modality to increase physiological responses of reflex and muscle activity, and muscle function, for athletes, the aged and compromised health. However, further research should focus on the optimum dose relationship of frequency, amplitude and duration for the various populations.

The short-term effect of whole-body vibration training on vertical jump, sprint, and agility performance.

Previous studies have suggested that short-term whole-body vibration (WBV) training produces neuromuscular improvement similar to that of power and strength training. However, it is yet to be determined whether short-term WBV exposure produces neurogenic enhancement for power, speed, and agility. The purpose of this study was to investigate the effect short-term WBV training had on vertical jump, sprint, and agility performance in nonelite athletes. Twenty-four sport science students (16 men and 8 women) were randomly assigned to 2 groups: WBV training or control. Each group included 8 men and 4 women. Countermovement jump (CMJ) height, squat jump (SJ) height, sprint speed over 5, 10, and 20 m, and agility (505, up and back) were performed by each participant before and after 9 days of either no training (control) or WBV training. Perceived discomfort of every participant was recorded after daily WBV exposure and nonexposure. There were no significant differences between WBV and control groups for CMJ, SJ, sprints, and agility. Perceived discomfort differed between the first and subsequent days of WBV training (p < 0.05); however, there was no difference between the WBV and control groups. It is concluded that short-term WBV training did not enhance performance in nonelite athletes.

A comparison of the physiologic effects of acute whole-body vibration exercise in young and older people

OBJECTIVE To examine the acute physiologic effects of acute whole-body vibration (WBV) exercise in young and older people. DESIGN Every participant performed 9 conditions in a static squat position, consisting of no vibration and WBV at 30Hz and 3 loads corresponding to (1) no load (0% body mass), (2) load of 20% body mass, and (3) load of 40% body mass. A Jendrassik voluntary contraction was also performed with no vibration and WBV at 30Hz with no load and 20% body mass. SETTING Laboratory facilities at a university in the United Kingdom. PARTICIPANTS Healthy young people (n=12; 6 men, 6 women; mean age, 21.5y) and 12 healthy older people (6 men, 6 women; mean age, 69.2y) from the local community. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES The Physical Activity Questionnaire, anthropometric measures, counter-movement jump, and isometric maximal voluntary contraction with the Jendrassik maneuver were assessed in both groups. Oxygen uptake (Vo2), blood pressure, heart rate, and rating of perceived exertion (RPE) were recorded during WBV and load conditions as the outcome of the study. RESULTS Both vibration and load were associated with an increase (P<.001) in Vo2 for older and young groups. WBV elicited the equivalent of a .35 metabolic equivalent (MET) increase in Vo2, with additional loads of 20% and 40% body mass increasing Vo2 by 0.8 and 1.2 METs, respectively. Additionally, there was an interaction effect of vibration and group in which the WBV-related Vo2 increase was less in the old compared with the young. Both vibration and load caused an increase in heart rate, blood pressure, and RPE (all P<.001); however, there were no significant group differences between young and older groups. The Jendrassik maneuver elicited an increase in Vo2 by 27.6% for the old and 33% for the young group (P<.001); however, there was no significant difference between groups. CONCLUSIONS Vo2 significantly increased in both the older and young people with vibration and additional load and when the Jendrassik maneuver was superimposed with vibration and load. However, the elicited increase in Vo2 (1.2mL x kg(-1).min(-1)) from WBV may be an insufficient stimulus to improve cardiovascular fitness.

Changes in joint angle, muscle‐tendon complex length, muscle contractile tissue displacement, and modulation of EMG activity during acute whole‐body vibration

It has been suggested that vibration causes small changes in muscle length, but to the best of our knowledge, these have yet to be demonstrated during whole‐body vibration (WBV). This was an observational study to determine whether acute WBV would result in muscle lengthening. We hypothesized that acute WBV would increase electromyography (EMG) activity concurrently with measurable changes in muscle contractile length. Nine healthy males performed two conditions on a Galileo vibration machine for 15 s at 0 HZ (resting) and 6 HZ at a set knee angle of 18°. Muscle tendon complex length, contractile tissue displacement of the medial gastrocnemius muscle, and EMG of soleus, tibialis anterior, and vastus lateralis muscles were measured. At 6 HZ the medial gastrocnemius (MG) muscle tendon complex (MTC) amplitude (375 μm) was significantly greater (P < 0.05) compared to 0 HZ (35 μm). The MG contractile length (CD) amplitude at 6 HZ (176 μm) was significantly greater (P < 0.01) compared to 0 HZ (4 μm). Significant increases (P < 0.05) in EMG modulation were found for all muscles during the 6 HZ compared to the 0 HZ condition. The major finding was that ≈50% of the elongation occurred within the muscle itself and was associated with preceding changes in EMG. This indicates muscle lengthening may be a prerequisite for eliciting stretch reflexes. In conclusion, there is a temporal association between EMG activity and muscle contractile tissue displacement where low‐frequency WBV results in small muscle length changes and increases muscle activation. Muscle Nerve, 2009

Effects of acute upper-body vibration on strength and power variables in climbers.

Whole-body vibration training has recently received a lot of attention with reported enhancements of strength and power qualities in athletes. This study investigated whether upper-body vibration would be able to augment muscular attributes for climbing performance. Twelve healthy active climbers volunteered for the study. All participants underwent 3 treatments—arm cranking (AC), upper-body vibration (UBV), and non-UBV (NUBV)—in a balanced random order, conducted on separate days. Upper-body vibration was generated via a commercialized electric-powered dumbbell with a rotating axis that delivered oscillatory movements to the shoulders and arms. The UBV treatment consisted of performing 5 upper-body exercises for a total duration of 5 minutes. The UBV frequency was set at 26 Hz, amplitude 3 mm. For the NUBV treatment, the participants performed the exact exercises and time constraints as UBV; however, the vibration dumbbell was set at 0 Hz and 0 mm amplitude. The third treatment consisted of AC, which was performed at 75 k·min-1 for 5 minutes. Pre-and postmuscular performance measures of medicine ball throw, hand grip strength, and a specific climbing maneuver were performed after each treatment. There were no significant treatment differences on medicine ball throw, hand grip strength, and the specific climbing maneuver. Acute UBV exposure did not demonstrate the expected potential neuromuscular enhancements on the climbing performance tests selected for this study.

Is 8 weeks of side-alternating whole-body vibration a safe and acceptable modality to improve functional performance in multiple sclerosis?

Purpose: To examine whether an 8-week period of side-alternating whole-body vibration (WBV) exercise is an acceptable and effective exercise intervention to improve and maintain functional performance in multiple sclerosis people. Methods: A total of 15 participants with MS (11 women [mean age 50.2 ± 6.9 years; body mass 65.7 ± 19.2 kg; height 165.3 ± 6.1 cm; EDSS 3.5 ± 0.9] and 4 males [mean age 50.5 ± 5.2 years; body mass 85.3 ± 16.0 kg; height 175.3 ± 3.2 cm; EDSS 3.4 ± 0.5]) were selected for this study. Quality of life, timed up-and-go, functional reach, standing balance and 10-m walk test were performed prior to and after 4 and 8 weeks of vibration exercise, and 2 weeks after cessation of vibration exercise. Results: There was no evidence of vibration exercise producing any anxiety or discomfort. Compared with baseline measurements, the 10-m walk test showed significant improvements in 2, 8 and 10 m times at 8 week (p < 0.05) and 2 week post-vibration (p < 0.05). Timed up-and-go demonstrated a significant and positive time effect (p < 0.05). Standing balance showed significant improvements from baseline, at 4- (p < 0.05) and 2-weeks post-vibration (p < 0.05). Conclusion: This is the first study to investigate side-alternating WBV as an exercise training modality for MS people. From an active MS population, this study has shown that WBV training not only improved the standing balance and walking time but there were also no adverse effects from using this modality. Implications for Rehabilitation Muscle weakness and fatigue are reported by most patients with multiple sclerosis (MS). Whole-body vibration (WBV) has gained popularity as an exercise modality in participants with either normal or compromised health. WBV is a safe and effective exercise intervention for persons with MS to improve and maintain functional ability and quality of life.

Comparing muscle temperature during static and dynamic squatting with and without whole-body vibration

The aim of this study was to investigate the influence of shallow dynamic squatting (DS) versus static squatting (SS) with or without concurrent side‐to‐side alternating whole‐body vibration (WBV) on vastus lateralis temperature and cardiovascular stress as indicated by heart rate (HR). Ten participants (five men, five women) participated in four interventions [DS with WBV (DS+), DS without WBV (DS−), SS with WBV (SS+), SS without WBV (SS−)] 48 h apart, in a randomized order. The interventions were preceded by a ∼20‐min rest period, consisted of 10 mins with or without WBV (26 or 0 Hz) with SS (40° of knee flexion) or DS (55° of knee flexion, at a cadence of 50 bpm) where SS+ and DS− were metabolically matched. Muscle (Tm), core (Tc), skin temperature (Tsk), HR and VO2 were recorded during each intervention. For Tm, there was a time (P<0·01) and WBV (P<0·01) effect but no squat effect was evident, and there was time ×WBV interaction effect (P<0·01). In all four interventions, the work load was too low to cause cardiovascular stress. Instead normal, moderate physiological effects of exercise on autonomic control were observed as indicated by HR; there were no significant increases in Tsk or Tc. There appears to be no benefit in performing an unloaded, shallow DS+ at a tempo of 50 bpm as Tm, HR, VO2 are likely to be increased by the same amount and rate without WBV. However, combining SS with WBV could be advantageous to rapidly increasing soft tissue temperature prior to performing rehabilitation exercises when dynamic exercise cannot be performed.

Does intermittent pneumatic leg compression enhance muscle recovery after strenuous eccentric exercise

Intermittent pneumatic compression (IPC) has gained rapid popularity as a post-exercise recovery modality. Despite its widespread use and anecdotal claims for enhancing muscle recovery there is no scientific evidence to support its use. 10 healthy, active males performed a strenuous bout of eccentric exercise (3 sets of 100 repetitions) followed by IPC treatment or control performed immediately after exercise and at 24 and 48 h post-exercise. Muscular performance measurements were taken prior to exercise and 24, 48 and 72 h post-exercise and included single-leg vertical jump (VJ) and peak and average isometric [knee angle 75º] (ISO), concentric (CON) and eccentric (ECC) contractions performed at slow (30° · s⁻¹) and fast (180° · s⁻¹) velocities. Plasma creatine kinase (CK) samples were taken at pre- and post-exercise 24, 48 and 72 h. Strenuous eccentric exercise resulted in a significant decrease in peak ISO, peak and average CON (30° · s⁻¹) at 24 h compared to pre-exercise for both IPC and control, however VJ performance remained unchanged. There were no significant differences between conditions (IPC and control) or condition-time interactions for any of the contraction types (ISO, CON, ECC) or velocities (CON, ECC 30° · s⁻¹ and 180° · s⁻¹). However, CK was significantly elevated at 24 h compared to pre-exercise in both conditions (IPC and control). IPC did not attenuate muscle force loss following a bout of strenuous eccentric exercise in comparison to a control. While IPC has been used in the clinical setting to treat pathologic conditions, the parameters used to treat muscle damage following strenuous exercise in healthy participants are likely to be very different than those used to treat pathologic conditions.

Is vibration exercise a useful addition to a weight management program

Vibration exercise (VbX) has received a lot of attention as an exercise modality, which evokes muscular work and elevates metabolic rate that could be a potential method for weight reduction. Popular press has purported that VbX is quick and convenient, and 10 min of VbX is equivalent to 1 h of traditional exercise, where it has been marketed as the new weight‐loss and body toning workout. However, research studies have shown that muscle activation occurs but the energy demand in response to VbX is quite low, where exhaustive VbX reported a metabolic demand of 23 mL/kg/min compared with 44 mL/kg/min from an exhaustive cycle test. Different vibration frequencies with varying amplitudes and loads have been tested, but only small increases in metabolic rate have been reported. Based on these findings, it has been indirectly calculated that a VbX session of 26 Hz for three continuous minutes would only incur a loss of ∼10.7 g fat/h. Following a 24‐week program of VbX, no observed differences were found in body composition, and following 12 months of VbX, the time to reach peak V ˙ O 2 was significantly higher in conventional exercise compared with VbX. However, one study has reported that percentage body fat decreased by 3.2% after 8 months after VbX in comparison with resistance and control groups that performed no aerobic conditioning. The evidence to date suggests that VbX can increase whole and local oxygen uptake; however, with additional load, high vibration frequency, and/or amplitude, it cannot match the demands of conventional aerobic exercise. Therefore, caution is required when VbX programs are solely used for the purpose of reducing body fat without considering dietary and aerobic conditioning guidelines.