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Strength Increase after Strength Increase after Whole Body Vibration Whole Body Vibration
Compared with Resistance Compared with Resistance training.training.
Christophe Delecluse, Sabine Verschueren, Machteld Christophe Delecluse, Sabine Verschueren, Machteld RoelantsRoelants
Faculteit Lichamelijke Opvoeding en KinesitherapieFaculteit Lichamelijke Opvoeding en Kinesitherapie
Katholieke Universiteit LeuvenKatholieke Universiteit Leuven
BelgiëBelgië
WBV-training: positive WBV-training: positive influence on muscle influence on muscle
strength?strength?
Lack of scientific supportLack of scientific support Mechanism:Mechanism:
vibration stimulusvibration stimulus
stimulation sensory receptors in muscle (presumably stimulation sensory receptors in muscle (presumably muscle spindles)muscle spindles)
activation alpha motor neuronsactivation alpha motor neurons
Tonic vibration reflex leading to muscle Tonic vibration reflex leading to muscle contraction: contraction:
stimulus for increase in strength?stimulus for increase in strength?
Studies acute effects WBVStudies acute effects WBV
Bosco et al. 1999 Bosco et al. 1999 (Clin Physiol):(Clin Physiol): volleyball players, increase in volleyball players, increase in strength-speed, strength-power leg pressstrength-speed, strength-power leg press
Bosco et al. 2000 Bosco et al. 2000 (Eur J Appl Physiol): (Eur J Appl Physiol): team sports, 7% increase team sports, 7% increase mechanical power knee-extensors (leg press), 3,8% increase jump mechanical power knee-extensors (leg press), 3,8% increase jump heightheight
Torvinen et al. 2002 Torvinen et al. 2002 (Clin Physiol & Func Im): (Clin Physiol & Func Im): 3,2% increase 3,2% increase isometric strength knee-extensors, 2,5% increase jump heightisometric strength knee-extensors, 2,5% increase jump height
Torvinen et al. 2002 Torvinen et al. 2002 (Int J Sports Med):(Int J Sports Med): nono effects on isometric effects on isometric strength knee-extensors, jump heightstrength knee-extensors, jump height
Bosco et al. 1998 Bosco et al. 1998 (Biol of Sport):(Biol of Sport): physically active subjects, 10 days physically active subjects, 10 days WBV-training, 6,1% increase in power, 12% increase jump heightWBV-training, 6,1% increase in power, 12% increase jump height
Runge et al. 2000 Runge et al. 2000 (J Musculoskel Neuron Interact)(J Musculoskel Neuron Interact): elderly subjects, 2 : elderly subjects, 2 months WBV-training, 18% increase in ‘chair rising time’months WBV-training, 18% increase in ‘chair rising time’
Torvinen et al. 2002 Torvinen et al. 2002 (Med Sci Sports and Exc): (Med Sci Sports and Exc): untrained subjects, 4 untrained subjects, 4 months WBV-training, 8,5% increase jump height, 2,5% increase months WBV-training, 8,5% increase jump height, 2,5% increase isometric strength knee-extensorsisometric strength knee-extensorsDe Ruiter et al. 2002 De Ruiter et al. 2002 (Geneeskunde en Sport)(Geneeskunde en Sport): physically active : physically active subjects,no improvement in isometric and explosive strength knee-subjects,no improvement in isometric and explosive strength knee-extensorsextensors
No unambiguous results:No unambiguous results:–Differences in training schedules, group Differences in training schedules, group
composition, composition, physical condition physical condition–No placebo groupNo placebo group–No comparison to regular resistance trainingNo comparison to regular resistance training
Long term WBV studiesLong term WBV studies
Purpose of this studyPurpose of this study
long term study:long term study:
– Investigate effects on isometric Investigate effects on isometric strength knee-extensors of exercises strength knee-extensors of exercises performed on platforms with and performed on platforms with and without vibration (placebo)without vibration (placebo)
– Compare effects to resistance training Compare effects to resistance training of moderate intensity (10-20RM)of moderate intensity (10-20RM)
MethodMethod
67 young ladies (21,4±1,8 jaar)67 young ladies (21,4±1,8 jaar) untraineduntrained 4 groups (random)4 groups (random)
WBV group, N=18WBV group, N=18Placebo group (PL), N=19Placebo group (PL), N=19Resistance group (RES), Resistance group (RES),
N=18N=18Control group (CO), N=12Control group (CO), N=12
12 weeks, 3 x/week (36 sessions)12 weeks, 3 x/week (36 sessions)
WBV group PL group WBV group PL group Static and dynamic exercises for knee-extensors: Static and dynamic exercises for knee-extensors:
squat, deep squat, one legged squat, squat, deep squat, one legged squat, lunge,...lunge,...
Vibration platformVibration platform (Power Plate®)(Power Plate®) progressive increase in progressive increase in
intensity and volumeintensity and volume
– 35-40Hz / 2,5-5,0mm35-40Hz / 2,5-5,0mm– 2,28 - 5,05g2,28 - 5,05g– Total vibration time Total vibration time
per session: 3-20 per session: 3-20 minmin
– rest period: 60-5 secrest period: 60-5 sec
Placebo platformPlacebo platform
- equal platform not - equal platform not resulting in increased resulting in increased muscle contractionmuscle contraction
- amplitude negligible- amplitude negligible
- acceleration only 0,4g- acceleration only 0,4g
0.4
0.3
0.2
0.1
0.0
EM
G a
ctivity (
V)
20151050
0.4
0.3
0.2
0.1
0.0EM
G a
ctivity (
V)
20151050
0.4
0.3
0.2
0.1
0.0
EM
G a
ctivity (
V)
20151050
Time (s)
rms=0.0461 rms=0.0528
rms=0.0603 rms=0.0641
rms=0.0591 rms=0.0798
WBV 35Hz
Placebo
Controlm. rectus femoris
EMG activity in the m. rectus EMG activity in the m. rectus femorisfemoris
(high squat)(high squat)
VIBRATION 35 Hz
EMG activity in the m. EMG activity in the m. gastrocnemiusgastrocnemius
0.12
0.08
0.04
0.00EM
G a
ctivity (
V)
20151050
0.12
0.08
0.04
0.00EM
G a
ctivity (
V)
20151050
0.12
0.08
0.04
0.00EM
G a
ctivity (
V)
20151050Time (s)
Vibration 35Hz
rms=0.00400 rms=0.02151
rms=0.00562rms=0.00447
rms=0.00570 rms=0.00571
WBV 35 Hz
Placebo
Controlm. gastrocnemius
Resistance-training groupResistance-training group
University fitness centreUniversity fitness centre 20 min warm up: bicycle, step, treadmill20 min warm up: bicycle, step, treadmill Resistance training schedule with moderate Resistance training schedule with moderate
intensity for knee-extensors (Kraemer 2002, intensity for knee-extensors (Kraemer 2002, ACSM)ACSM)
leg press, leg extension (Technogym®): 2 setsleg press, leg extension (Technogym®): 2 sets
W1 W3 W6 W9 W12
20 RM 15 RM 12 RM 10RM
Pre-post measuringPre-post measuring
Iso-kinetic dynamometer Iso-kinetic dynamometer
(REV9000, Technogym®)(REV9000, Technogym®)
maximum voluntary isometric maximum voluntary isometric
strength knee-extensors strength knee-extensors
(angle in knee: 130°)(angle in knee: 130°)
post-test: min. 72 hours after post-test: min. 72 hours after
last training sessionlast training session
Results (1)Results (1)
ISO †
110
130
150
170
190
210
230
KRN=18
WBVN=18
PLN=19
CON=12
Group
Kn
ee-e
xten
sor
mom
ent
(N.m
)
pre
post* *
Results (2)Results (2)
Isometric strengthIsometric strength– significant interaction effect (group x time)significant interaction effect (group x time)
F (3)=15,94; P<0.001 (ANOVA for repeated F (3)=15,94; P<0.001 (ANOVA for repeated measurements)measurements)
– significant increase (P<0.001) pre-post (contrast significant increase (P<0.001) pre-post (contrast analysis):analysis):
in WBV group: 16,6 ± 10,8% in WBV group: 16,6 ± 10,8% in RES group: 14,4% ± 5,3%in RES group: 14,4% ± 5,3%
– no significant difference (P>0.05) pre-post:no significant difference (P>0.05) pre-post: in PL group: 3,8 ± 11,4 %in PL group: 3,8 ± 11,4 % in CO group: -7,3 ± 15,9%in CO group: -7,3 ± 15,9%
Causes of strength gainCauses of strength gain
Hypothesis: strength gain after 12 weeks Hypothesis: strength gain after 12 weeks WBV mainly due to neural adaptations ~ WBV mainly due to neural adaptations ~ resistance training resistance training (Enoka 1997, (Enoka 1997, J BiomechJ Biomech))
– extensive sensory stimulation: possible more extensive sensory stimulation: possible more efficient use of sensory information in efficient use of sensory information in production of strengthproduction of strength
input of proprioceptors (Ia, IIa, Ib) is used input of proprioceptors (Ia, IIa, Ib) is used in building up isometric strength in building up isometric strength (Gandevia (Gandevia 2001, 2001, Physiol RevPhysiol Rev))
Conclusions (1)Conclusions (1)
The muscle contractions during WBV efficient The muscle contractions during WBV efficient stimulus for strength gain in knee extensors in stimulus for strength gain in knee extensors in untrained subjectsuntrained subjects
Torvinen et al. 2002: Torvinen et al. 2002: – only 3,7% increase in strength in knee-only 3,7% increase in strength in knee-
extensors after 2 months WBV-training extensors after 2 months WBV-training placebo effect this studyplacebo effect this study
– this study: 16,6%this study: 16,6%
Difference in training schedule: time, volume, intensity,…
‘full motor unit activation’ leads to fatigue in motor units = stimulus to strength gain
(Sales 1987, Exerc Sport Sci Rev)
Conclusions (2)Conclusions (2)
12 weeks WBV training with untrained 12 weeks WBV training with untrained ladies:ladies:– Strength gain in knee-extensors comparable to Strength gain in knee-extensors comparable to
resistance training of moderate intensity (10-resistance training of moderate intensity (10-20RM)20RM)
– effect not attributable to stance or exercises on effect not attributable to stance or exercises on platform but to increased muscle activity (EMG) platform but to increased muscle activity (EMG) during WBVduring WBV
NO placebo-effectNO placebo-effect
Strength gain following 12 weeks of Strength gain following 12 weeks of whole body vibration trainingwhole body vibration training– C. Delecluse, M. Roelants, S. C. Delecluse, M. Roelants, S.
VerschuerenVerschueren Published in Published in Medicine and Science in Sports Medicine and Science in Sports
and Exercise and Exercise Vol.35, No.6, pp. 1033-1041, Vol.35, No.6, pp. 1033-1041, 20032003