Acute Effects of Whole-Body Vibration Exercises at 2 Different Frequencies Versus an Aerobic Exercise on Some Cardiovascular,Neuromotor and Musculoskeletal Parameters in Adult Patients With Obesity

Abstract

Whole-body vibration exercise (WBVE), a nonimpact, viable and safe type of exercise, has been reported to be useful in the physical rehabilitation of obesity. Aim of the study was to compare the acute effects of WBVE with a session of walking and running (AER) on cardiovascular, neuromotor and musculoskeletal parameters in obese subjects. Sixteen adult obese subjects performed 3 tests (WBVE at 30 and 45 Hz, AER) randomly in different days. An increase in heart rate was recorded after AER and 45 Hz WBVE (p < 0.001), while only AER increased systolic (p = 0.003) and diastolic blood pressure (p = 0.004) and ratings of perceived exertion (p < 0.001). All 3 exercises determined lactate increase [AER p < 0.001, 45 Hz (p = 0.04), 30 Hz (p = 0.03) WBVE] and sit-and-reach (AER p = 0.002, 45 and 30 Hz WBVE p < 0.001) and fingertip-to-floor improvements (AER p = 0.003, 30 and 45 Hz WBVE p < 0.001), while only 30 Hz WBVE determined improvement in stair climbing test (p < 0.05). Considering the lack of effects of 30 Hz WBVE on the cardiovascular system and fatigue and its positive effect on flexibility and muscle power, this procedure can be considered an appropriate exercise protocol for the obese population.

Keywords

obesity whole-body vibration aerobic exercise rehabilitation flexibility

Introduction

Obesity has progressively become a largely widespread clinical condition, affecting quality of life and resulting in many functional physical limitations¹ which frequently hamper these patients to perform common daily routine activities (i.e. walking, climbing stairs, etc.).² In particular flexibility, which is important to perform both simple and complex movements involved in daily activity,³ is gradually impaired in subjects with obesity, causing postural changes which further compromise their motor performance.⁴

Increased physical activity is a fundamental element in the comprehensive lifestyle intervention and in the clinical rehabilitation of individuals with obesity,¹ who need specific physical exercises aiming to improve different components of their physical fitness.

Authors reported that general aerobic warm-up protocols, such as brisk walking, jogging or running, are able to improve muscle performance⁵ and also flexibility since warmer muscle are more extensible.⁶ However, it is clearly evident that running is not always an appropriate exercise for obese subjects, considering that their excessive body mass causes a greater impact force when the foot lands on the ground increasing their risk of injury,⁷ joint pain and inflammation due to the overload on joints⁸ and higher physical fatiguability.⁹

Whole-body vibration exercise (WBVE) is reported to be a safe, feasible and non-impact type of exercise, able to improve physical fitness, furthermore suitable and well-tolerated by patients with different disorders,^10
-12 including obesity.¹³ WBVE is able to improve both muscle strength¹⁴ and flexibility,³ these improvements being hardly achieved with the other traditional training exercises¹⁵ requiring a higher level of agility.

The ability of WBVE to increase flexibility and muscle power involves muscular, neural, circulatory and thermoregulatory factors.¹⁶ WBVE stimulates blood circulation by increasing peripheral blood flow without altering skeletal muscle oxygenation¹⁷ and generating a thermal effect, which is widely used in facilitating flexibility.^18,19 Moreover, WBVE induces non-voluntary muscle contractions followed by muscle relaxation and raises the pain threshold allowing to stretch further.¹⁶

Several studies have indeed reported that WBVE can lead to greater improvements in both muscle strength and power,^14,20,21 so it can be considered to be a highly effective tool to enhance muscular performance.

An important factor to be considered in WBVE is vibration frequency of the mechanical vibration generated in the vibrating platform that is transmitted to the individual.¹⁶ In fact, it has been reported how frequency is a fundamental parameter that can influence and change the general WBVE positive effects. In this context, lower frequencies (i.e. equal or below to 35 Hz) have shown acute enhancement in neuromuscular performance, flexibility²² and muscle activity^23,24 compared to higher frequencies^22,25 (i.e. above 40 Hz).

Taking into account all the above considerations, the aim of the present study is to compare the acute effects of WBVE at 2 different frequencies (30 Hz and 45 Hz) with those obtained following a session of walking and running at constant speed on some cardiovascular, neuromotor and musculoskeletal parameters, in particular flexibility and lower limb muscle power, in a group of adult subjects with obesity.

Methods

Participants

Sixteen adults with severe obesity (7 males and 9 females) were recruited for this study (mean ± standard deviation: age 32.2 ± 7.6 years; body mass (BM): 123.6 ± 21.7 kg; height: 1.68 ± 0.1 m; body mass index (BMI): 44.2 ± 8.6 kg/m²). All the participants were hospitalized for a 3-week multidisciplinary integrated body weight reduction program at the Division of Metabolic Diseases, Istituto Auxologico Italiano, Verbania, Italy. Before the admission to the study protocol, all the patients gave their written consent after being fully informed of the nature and the procedures of the study. The protocol was approved by the Ethical Committee of Istituto Auxologico Italiano, Milan, Italy (project code: 01C026_2020, acronym: VIBRADUOB).

All of the participants were sedentary and were not involved in any strenuous activity in the 48 hours preceding the first experimental session. None of them reported any cardiorespiratory problem or musculoskeletal disorder that could have influenced the execution of the 3 interventions.

Training Sessions

Each training session was performed in the morning and the participants were admitted to the laboratory 1 hour before the beginning of the tests. Each patient performed 3 tests, in random order and in different days: (1) aerobic session (walking/running, AER), (2) WBVE at 30 Hz (30 Hz WBVE), (3) WBVE at 45 Hz (45 Hz WBVE). The randomization was obtained throughout the use of the “random sequence generator” available on the website random.org. The training sessions lasted 15 minutes each and were separated by a day of rest as wash-out period.

The AER session was performed on a motorized treadmill (RUN-XT 500, Technogym S.p.A., Cesena, Italy) without inclination. Subjects started with a 5-minute walk at a constant speed of 3 km/h, followed by a 10-minute light run at a constant speed of 5 km/h.

During the 30 Hz WBVE session, individuals stood in a static squat position with a 130° knee flexion on the vibrating platform (Nevisys H1©, RME, Ferrara, Italy) with vertical sinusoidal vibrations at a frequency of 30 Hz and a peak-to-peak displacement of 3 mm for 60 seconds. The acceleration peak of the vibration was 2.85 g, as assessed by magnetic monoaxial accelerometer (Vibration Meter, Lutron VB-8200). Then, subjects rested for 30 seconds in a relaxed stood position on the vibrating platform. This sequence was repeated 10 times in a row. The 130° knee flexion was controlled by using a large articulation Jamar stainless steel goniometer (Performance Health, Warrenville, IL, USA) by a trained researcher.

During the 45 Hz WBVE session, individuals performed the same test just described for 30 Hz, but with the vibrating platform set at a frequency of 45 Hz and peak-to-peak displacement of 3 mm.

Outcome Measures

Anthropometric Measures

A scale with a stadiometer (Wunder Sa.Bi., WU150, Trezzo sull’Adda, Italy) was used to determine height and weight. BMI was calculated as the ratio between BM (kg) and height squared (m²).

Body composition was evaluated by a multifrequency tetrapolar impedancemeter (BIA, Human-IM Scan, DS-Medigroup, Milan, Italy) with a delivered current of 800 µA at a frequency of 50 kHz. In order to reduce errors of measurement, attention was paid to the standardization of the variables that affect measurement validity, reproducibility, and precision. Measurements were performed according to the method of Lukaski et al. (1987)²⁶ after 20 minutes of rest in a supine position with arms and legs relaxed and not in contact with other body parts. Fat free mass (FFM) was calculated using the predictive equation developed by Lazzer et al. (2008),²⁷ and fat mass (FM) was derived as the difference between BM and FFM.

All the following parameters were evaluated before and immediately after the end of each 1 of the 3 exercise sessions.

Blood Pressure, Heart Rate and Peripheral Oxygen Saturation

Systolic (SBP) and diastolic (DBP) blood pressure were measured twice (3-min interval in-between) on the dominant arm with an aneroid sphygmomanometer (TemaCertus, Milan, Italy), by using appropriated sized cuffs. Heart rate (HR) and peripheral oxygen saturation (SpO₂) were measured with a pulse oximetry device (Nonin Medical Inc., Plymouth, MN, USA) placed on the patient’s second finger.

Rating of Perceived Exertion

Ratings of perceived exertion (RPE), defined by the feelings of general fatigue, stress, strain and discomfort felt by the participant, were obtained before and immediately after each training session and determined by using the Borg CR10 scale.²⁸

Stair Climbing Test

The stair climbing test (SCT) is a standardized procedure, previously validated by our group, used to measure maximal lower limb muscle power and assess motor control.^29
-31 In this test, subjects were asked to climb up ordinary stairs (13 steps of 15.3 cm each vertical distance 1.99 m) at their highest speed, in accordance to their capabilities. The SCT time (T_SCT) taken to climb the stairs, one step at a time, starting when the foot was elevated and finishing with the contact of the foot on the last step, was measured with a digital stopwatch. The SCT power (P_SCT) was calculated by using the following equation^31,32:

P_{SCT} = \frac{bm× h × g}{T_{SCT}},

where “bm” represents body mass (in kg), “h” is height (in m) of the total vertical distance of the stairs and “g” is the acceleration of gravity (9.81 m/s²).

The P_SCT values obtained with the equation were normalized by BM and by FFM.

Sit-and-Reach

Subjects performed the sit-and-reach test (SR) for flexibility, according to the protocol described by Chen et al.³³ A flexible measuring tape was fixed to an exercise mat where subjects sat keeping their knees extended and the tape between their legs. Subjects were asked to reach forward slowly, as far as possible, with their hands overlapped and to hold the end position for 2 seconds. Three attempts were allowed and the mean farthest point reached with the fingertips was the obtained SR distance. The level of the heels was used as recording zero so that any measure that did not reach the heels was negative and any measure beyond the heels was positive.

Fingertip-to-Floor Test

The fingertip-to-floor test (FTF) was also used to analyzed patient’s flexibility. In this test, subjects stood erect on the vibrating platform, without shoes and keeping their feet together, and were asked to bend forward as far as possible, while maintaining the knees, arms, and fingers fully extended. The vertical distance between the tip of the middle finger and the platform was measured with a measuring tape. The vertical distance between the platform and tip of the middle finger was positive for any measure that did not reach the platform and negative for any that could go further.³⁴

Lactate

Before each training session, a small blood sample (5 μL) was obtained from the earlobe for the determination of basal lactate (LA) concentration. The same procedure was performed immediately after the end of every exercise and at 2-min intervals until the detection of the peak value. Blood LA was measured by a portable analyzer (Lactate Pro 2, Akray, Japan).

Statistical Analysis

All continuous variables were reported as mean ± standard deviation. The nonparametric Wilcoxon signed rank sum test was used to test the differences between baseline and post-exercise (i.e. after) values for each variable of interest of each session. In addition, the delta (Δ) value (between baseline and post-exercise) for each variable was also calculated. The Friedman test was used for baseline comparison and inter-group comparison of delta values. A level of significance of p < 0.05 was used for all data analyses.

Results

Anthropometric data (height, body mass, BMI, FM, FFM) of the study group are reported in Table 1.

Table 1.

Anthropometric Data of the Study Group.^a

n	Sex (m/f)	Age (years)	Height (m)	Body mass (kg)	BMI (kg/m²)	FM (kg)	FFM (kg)
16	7/9	32.2 ± 7.6	1.68 ± 0.1	123.6 ± 21.7	44.2 ± 8.6	61.6 ± 16.8	62.2 ± 13.4

BMI: body mass index; FM: fat mass; FFM: fat free mass.

^a Data are shown as mean ± standard deviation.

Baseline values of SBP, DBP, HR, SpO₂, RPE, LA, SR, FTF, P_SCT and P_SCT normalized by BM and by FFM were comparable in the 3 experimental interventions, the only exception being observed for T_SCT (p < 0.05).

The effects of AER, 30 Hz WBVE and 45 Hz WBVE on SBP, DBP, HR and SpO₂ are shown in Table 2.

Table 2.

Effects of AER, 30 Hz WBVE and 45 Hz WBVE on SBP, DBP, HR and SpO₂.^a

	AER (intra-group comparison)			30Hz WBVE (intra-group comparison)			45Hz WBVE (intra-group comparison)
	Baseline, Mean ± SD	After, Mean ± SD	p value	Baseline, Mean ± SD	After, Mean ± SD	p value	Baseline, Mean ± SD	After, Mean ± SD	p value
SBP (mm Hg)	120.9 ± 9.2	130.9 ± 12.4	0.003	120.3 ± 11.2	115.4 ± 6.9	0.09	118.3 ± 11.8	119.2 ± 10.6	0.64
DBP (mm Hg)	77.8 ± 5.5	83.2 ± 4.6	0.004	81.4 ± 8.6	77.2 ± 8.9	0.27	78.7 ± 8.86	79.1 ± 6.7	0.68
HR (bpm)	87.1 ± 11.7	116.4 ± 22.3	<0.001	85.4 ± 7.8	86.1 ± 8.2	0.80	83.4 ± 10.6	88.8 ± 10.3	<0.001
SpO₂ (%)	96.6 ± 1.4	96.4 ± 1.7	0.92	97.1 ± 1.1	96.6 ± 1.1	0.13	96.8 ± 1.7	96.1 ± 1.2	0.08

WBVE: whole-body vibration; SD: standard deviation; SBP: systolic blood pressure; mmHg: millimeters of mercury; DBP: diastolic blood pressure; HR: heart rate; bpm: beats per minute; SpO₂: peripheral oxygen saturation; statistical significance was set at p < 0.05.

^a Data are shown as mean ± standard deviation.

SBP and DBP values significantly increased after AER (p = 0.003 and p = 0.004, respectively), while no significant effects were recorded following 30 Hz WBVE and 45 Hz WBVE.

HR significantly increased after AER (p < 0.001) and after 45 Hz WBVE (p < 0.001), no effects being detected after 30 Hz WBVE.

SpO₂ values were not modified after the 3 experimental condition.

The mean Δ values between basal and post-exercise of these parameters and the results of the inter-group comparison are shown in Table 3. The changes of SBP, DBP and HR were significantly different between the 3 interventions, while no difference were recorded in SpO₂.

Table 3.

Effects of AER, 30 Hz WBVE and 45 Hz WBVE on SBP, DBP, HR and SpO₂, Inter-Group Comparison of the Delta Values.^a

	Δ SBP (mm Hg)			Δ DBP (mm Hg)			Δ HR (bpm)			Δ SpO₂ (%)
	AER	30 Hz WBVE	45 Hz WBVE	AER	30 Hz WBVE	45 Hz WBVE	AER	30 Hz WBVE	45 Hz WBVE	AER	30 Hz WBVE	45 Hz WBVE
Mean ± SD	9.9 ± 11.4	−4.9 ± 10.1	0.9 ± 9.4	5.4 ± 6.6	−4.3 ± 11.8	0.4 ± 5.3	29.3 ± 22.3	0.6 ± 6.5	5.4 ± 4.7	−0.2 ± 2.3	−0.4 ± 1.1	−0.7 ± 2.0
p value	0.0003			0.03			0.0002			0.48

^a Data are shown as mean ± standard deviation.

The effects of AER, 30 Hz WBVE and 45 Hz WBVE on fatigue, flexibility, lower limb muscle power and LA concentrations are shown in Table 4.

Table 4.

Effects of AER, 30 Hz WBVE and 45 Hz WBVE on Fatigue, Flexibility, Lower Limb Muscle Power and LA Concentration.^a

	AER (intra-group comparison)			30 Hz WBVE (intra-group comparison)			45 Hz WBVE (intra-group comparison)
	Baseline, Mean ± SD	After, Mean ± SD	p value	Baseline, Mean ± SD	After, Mean ± SD	p value	Baseline, Mean ± SD	After, Mean ± SD	P value
RPE	0.3 ± 0.5	3.7 ± 2.4	<0.001	0.4 ± 0.6	0.5 ± 0.7	0.79	0.3 ± 0.4	0.4 ± 0.4	0.20
LA (mmol/L)	1.6 ± 0.3	4.9* ± 2.3	<0.001	1.5 ± 0.3	1.7* ± 0.3	0.03	1.5 ± 0.4	1.7* ± 0.3	0.04
SR (cm)	−4.3 ± 9.88	−1.6 ± 9.13	0.002	−4.2 ± 9.9	−1.8 ± 9.8	<0.001	−4.3 ± 10.8	−0.4 ± 10.2	<0.001
FTF (cm)	4.1 ± 12.1	1.1 ± 10.4	0.003	3.9 ± 11.6	0.6 ± 11.4	<0.001	4.9 ± 11.14	1.2 ± 11.0	<0.001
T_SCT (s)	4.25 ± 1.37	4.27 ± 1.67	0.28	4.2 ± 1.56	4.14 ± 1.58	0.049	4.24 ± 1.48	4.15 ± 1.33	0.39
P_SCT (W)	590.0 ± 145.2	606.1 ± 148.3	0.15	603.2 ± 129.1	616.2 ± 136.3	0.03	596.7 ± 128.5	602.6 ± 118.5	0.45
P_SCT/BM (W/kg)	4.87 ± 1.20	5.02 ± 1.24	0.51	5.00 ± 1.10	5.10 ± 1.17	0.04	4.93 ± 1.08	4.98 ± 1.00	0.48
P_SCT/FFM (W/kg)	9.84 ± 2.82	10.09 ± 2.80	0.17	10.04 ± 2.47	10.2 ± 2.80	0.04	9.93 ± 2.45	10.03 ± 2.29	0.39

WBVE: whole-body vibration; SD: standard deviation; RPE: rating of perceived exertion; LA: lactate; *: value at peak; SR: sit-and-reach; FTF: fingertip-to-floor test; T_SCT: time of stair climbing test; P_SCT: power of stair climbing test; W: watts; BM: body mass, FFM: fat free mass, statistical significance was set at p < 0.05.

^a Data are shown as mean ± standard deviation.

RPE significantly increased only after AER (p < 0.001), no significant changes being observed after WBVE, both at 30 Hz and at 45 Hz, while LA significantly increased after all the 3 experimental conditions (AER p < 0.001, 30 Hz WBVE p = 0.03, 45 Hz WBVE p = 0.04).

AER, 30 Hz WBVE and 45 Hz WBVE determined a marked improvement of SR (p = 0.002 for AER and p < 0.001 for both 30 Hz and 45 Hz WBVE) and of FTF (p = 0.003, p < 0.001 and p < 0.001, respectively).

T_SCT was not modified by AER and 45 Hz WBVE, while a significant time reduction was observed after 30 Hz WBVE (p = 0.049). As a direct consequence, P_SCT did not change after AER and 45 Hz WBVE, while it significantly increased after 30 Hz WBVE (p = 0.03) even when normalized by BM and FFM (p = 0.04 for both normalizations).

The mean Δ values between basal and post-exercise of these parameters and the results of the inter-group comparison are shown in Table 5. The changes of RPE and LA were significantly different between the 3 interventions, while no differences were recorded in SR, FTF, T_SCT, P_SCT, P_SCT/BM and P_SCT/FFM.

Table 5.

Effects of AER, 30 Hz WBVE and 45 Hz WBVE on Fatigue, Flexibility, Lower Limb Muscle Power and LA Concentration, Inter-Group Comparison of the Delta Values.^a

	Δ RPE			Δ LA (mmol/L)			Δ SR (cm)			Δ FTF (cm)
	AER	30 Hz WBVE	45 Hz WBVE	AER	30 Hz WBVE	45 Hz WBVE	AER	30 Hz WBVE	45 Hz WBVE	AER	30 Hz WBVE	45 Hz WBVE
Mean ± SD	3.4 ± 2.4	0.1 ± 0.6	0.1 ± 0.3	3.3 ± 2.2	0.2 ± 0.3	0.2 ± 0.4	2.6 ± 2.4	2.4 ± 2.0	3.9 ± 2.3	−3.0 ± 2.7	−3.3 ± 2.5	−3.8 ± 2.3
p value	< 0.001			< 0.001			0.28			0.19
	Δ T_SCT (s)			Δ P_SCT (W)			Δ P_SCT/BM (W/kg)			Δ P_SCT/FFM (W/kg)
	AER	30 Hz WBVE	45 Hz WBVE	AER	30 Hz WBVE	45 Hz WBVE	AER	30 Hz WBVE	45 Hz WBVE	AER	30 Hz WBVE	45 Hz WBVE
Mean ± SD	0.1 ± 0.3	−0.1 ± 0.2	−0.1 ± 0.2	−3.5 ± 50.9	13.0 ± 24.3	5.9 ± 18.5	0.0 ± 0.4	0.1 ± 0.2	0.0 ± 0.2	−0.1 ± 0.8	0.2 ± 0.5	0.1 ± 0.3
p value	0.25			0.45			0.45			0.45

WBVE: whole-body vibration; SD: standard deviation; RPE: rating of perceived exertion; LA: lactate; SR: sit-and-reach; FTF: fingertip-to-floor test; T_SCT: time of stair climbing test; P_SCT: power of stair climbing test; W: watts; BM: body mass, FFM: fat free mass, statistical significance was set at p < 0.05.

^a Data are shown as mean ± standard deviation.

Discussion

It is well known that obesity is associated to physical impairments, which prevent the accomplishment of common daily routine activities.² Lifestyle interventions are fundamental for the rehabilitation of subjects with severe obesity, mainly devoted to introduce physical activity into their life and to ameliorate their musculoskeletal functions.³⁵ However, it is fundamental to find the appropriate type of exercise that has to be effective, safe, acceptable, adapted and suitable for the obese population.¹

For these reasons, the aim of the present study was to establish whether WBVE, a nonimpact, viable, and safe type of exercise, suitable and well-tolerated by the obese population, would be able to determine beneficial effects on some musculoskeletal parameters, in particular flexibility and lower limb muscle power, and to compare these effects to those obtained with a classical session of walking and running. WBVE was performed at 2 different frequencies, one lower, 30 Hz, and one higher, 45 Hz to determine which protocol has the best outcome.

No significant changes were observed in SpO₂ after the 3 tests. WBVE did not determine any statistically significant changes in SBP and DBP, while a significant increase in both parameters was observed after AER. HR significantly increased after AER and after 45 Hz WBVE, whereas it was not modified after 30 Hz WBVE. Taking into account that only 30 Hz WBVE did not determine any effect on HR and blood pressure, both systolic and diastolic, WBVE at this specific frequency might be considered as a safe choice for the obese population, considering their well-known increased cardiovascular risk.³⁶

AER was associated with a significant increase in RPE, while no changes were observed after the 2 WBVE, this finding indicating that only AER determined fatigability in obese patients. Fatigue in an important parameter to be taken into consideration since obese individuals are reported to suffer from a lower fatigue resistance,³⁷ causing a greater chance of withdraw during physical rehabilitation.

Although it is undoubt that the AER-induced monitored changes in cardiovascular parameters may be very positive and desired, the employment of WBVE (not impacting on HR, SBP and DBP) can be useful at least in the first phases of multidisciplinary metabolic rehabilitation for severely hospitalized obese patients (as ours). AER exercises represented and will represent obviously a not replaceable opportunity in our standardized protocols for these patients, which could be integrated by WBVE in the future.

LA levels at peak were significantly increased after all 3 exercises, being although significantly higher after the AER session than after both WBVE.

All 3 exercises determined a significant and comparable increase in flexibility, which was assessed through SR and FTF. Since flexibility is a physical feature particularly important in the maintenance of the mobility and in the ability to move joints and considering its impairment in obesity,³ its improvement is highly desirable for the obese subjects to preserve their capability to perform daily activities.

Interestingly, only 30 Hz WBVE was able to reduce T_SCT, indicating an improvement in the stair climbing performance and consequently a significant increase in P_SCT, even when normalized by BM and FFM, indicating that this effect is independent of body weight and body composition. The exclusive ability of WBVE administered at 30 Hz to enhance lower limb muscle power represents an indication to use this frequency for obtaining these beneficial effects on muscular performance. A plausible explanation for the specific effect of 30 Hz WBVE on T_SCT (and derived indexes) might be related to the lower effect on fatiguability and RPE in comparison with AER, while it remains to be elucidated the difference observed with the 2 WBVE frequencies.

These findings are in agreement with our previous observation,¹³ demonstrating that WBVE at a low frequency (i.e. 35 Hz) was capable of improving both flexibility and muscle power without affecting the cardiovascular system in male obese adolescents.

Although the results of our studies (the above mentioned¹³ and the present one) suggest that both adults and adolescents suffering from severe obesity can benefit from WBVE, it should be however mentioned that the results of this preliminary study should be carefully interpreted considering the small obese population recruited. Another limitation requiring to be mentioned is the lack of a control group, which it should have been useful to understand the benefits of the 3 interventions in a better way. In this respect, further additional studies with larger study population (including also a control group) are requested to confirm these preliminary observations.

As conclusion, taking all the above findings into consideration, 30 Hz WBVE appears to be a satisfactory exercise protocol, capable to determine a significant acute improvement in flexibility and muscle power without affecting the cardiovascular system and without overloading joints. Moreover, since the majority of obese subjects has a sedentary lifestyle and is frequently reluctant to start an exercise program, WBVE might represent a form of well-tolerated exercise to be considered in their physical rehabilitation in order to gradually introduce physical activity and avoid the risk of withdraw.

Footnotes

Authors’ Note

A.S., S.T. and M.B.F. designed the study. R.D.M. and G.T. enrolled the participants and performed the tests. S.T., R.D.M. and G.T. elaborated the database and analyzed the data. S.T., A.S. and M.B.F wrote the manuscript. R.D.M. and G.T. contributed to the interpretation and discussion writing. All authors contributed to the revision of manuscript. The present study was approved by the ethical committee of Istituto Auxologico Italiano (research project code: 01C026_2020, acronym: VIBRADUOB). Written informed consent was obtained from the parents of all patients.

Acknowledgments

The authors thank the nursing staff at the Division of Metabolic Diseases, Istituto Auxologico Italiano, Piancavallo, VB, Italy. Special acknowledgments are addressed to the patients and their families for their willingness to participate in this research.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The study was supported by Progetti di Ricerca Corrente, Istituto Auxologico Italiano, IRCCS, Milan, Italy (research project code: 01C026_2020, acronym: VIBRADUOB).

ORCID iD

Sofia Tamini

References

Bray

Frühbeck

Ryan

Wilding

JPH

. Management of obesity. Lancet. 2016;387(10031):1947–1956. doi:10.1016/S0140-6736(16)00271-3

Abdelaal

le Roux

Docherty

. Morbidity and mortality associated with obesity. Ann Transl Med. 2017;5(7):161. doi:10.21037/atm.2017.03.107

da Cunha Sá-Caputo

Ronikeili-Costa

Carvalho-Lima

, et al. Whole body vibration exercises and the improvement of the flexibility in patient with metabolic syndrome. Rehabil Res Pract. 2014;2014:628518. doi:10.1155/2014/628518

Larsson

Mattsson

. Functional limitations linked to high body mass index, age and current pain in obese women. Int J Obes. 2001;25(6):893–899. doi:10.1038/sj.ijo.0801553

Pinfold

Harnett

Cochrane

. The acute effect of lower-limb warm-up on muscle performance. Res Sports Med. 2018;26(4):490–499. doi:10.1080/15438627.2018.1492390

Beaulieu

. Developing a stretching program. Phys Sportsmed. 1981;9(11):59–69. doi:10.1080/00913847.1981.11711207

Nielsen

Bertelsen

Parner

Sørensen

Lind

Rasmussen

. Running more than three kilometers during the first week of a running regimen may be associated with increased risk of injury in obese novice runners. Int J Sports Phys Ther. 2014;9(3):338–345.

Vincent

. Considerations for initiating and progressing running programs in obese individuals. PM R. 2013;5(6):513–519. doi:10.1016/j.pmrj.2013.03.008

Martinez-Amezcua

Simonsick

Wanigatunga

, et al. Association between adiposity and perceived physical fatigability in mid- to late life. Obesity. 2019;27(7):1177–1183. doi:10.1002/oby.22500

10.

Stania

Juras

Słomka

Chmielewska

Król

. The application of whole-body vibration in physiotherapy—a narrative review. Physiol Int. 2016;103(2):133–145. doi:10.1556/036.103.2016.2.1

11.

Park

S-Y

Son

W-M

Kwon

O-S

. Effects of whole body vibration training on body composition, skeletal muscle strength, and cardiovascular health. J Exerc Rehabil. 2015;11(6):289–295. doi:10.12965/jer.150254

12.

Lai

Wang

Lee

Hou

Wang

. Effects of whole body vibration exercise on neuromuscular function for individuals with knee osteoarthritis: study protocol for a randomized controlled trial. Trials. 2017;18(1):437. doi:10.1186/s13063-017-2170-6

13.

Sousa-Gonçalves

Tringali

Tamini

, et al. Acute effects of whole-body vibration alone or in combination with maximal voluntary contractions on cardiorespiratory, musculoskeletal, and neuromotor fitness in obese male adolescents. Dose Response. 2019;17(4):1559325819890492. doi:10.1177/1559325819890492

14.

Alam

Khan

Farooq

Effect of whole-body vibration on neuromuscular performance: a literature review. Work. 2018;59(4):571–583. doi:10.3233/WOR-182699

15.

Annino

Iellamo

Palazzo

, et al. Acute changes in neuromuscular activity in vertical jump and flexibility after exposure to whole body vibration. Medicine. 2017;96(33):e7629. doi:10.1097/MD.0000000000007629

16.

Issurin

VB.

Vibrations and their applications in sport. A review. J Sports Med Phys Fitness. 2005;45(3):324–336.

17.

Games

Sefton

Wilson

. Whole-body vibration and blood flow and muscle oxygenation: a meta-analysis. J Athl Train. 2015;50(5):542–549. doi:10.4085/1062-6050-50.2.09

18.

Funk

Swank

Adams

Treolo

. Efficacy of moist heat pack application over static stretching on hamstring flexibility. J Strength Cond Res. 2001;15(1):123–126.

19.

Petrofsky

Laymon

Lee

. Effect of heat and cold on tendon flexibility and force to flex the human knee. Med Sci Monit. 2013;19:661–667. doi:10.12659/MSM.889145

20.

Osawa

Oguma

Ishii

. The effects of whole-body vibration on muscle strength and power: a meta-analysis. J Musculoskelet Neuronal Interact. 2013;13(3):380–390.

21.

Petit

P-D

Pensini

Tessaro

Desnuelle

Legros

Colson

. Optimal whole-body vibration settings for muscle strength and power enhancement in human knee extensors. J Electromyogr Kinesiol. 2010;20(6):1186–1195. doi:10.1016/j.jelekin.2010.08.002

22.

Cardinale

Lim

. The acute effects of two different whole body vibration frequencies on vertical jump performance. Med Sport. 2003;56(4):287–292.

23.

Pollock

Woledge

Mills

Martin

Newham

. Muscle activity and acceleration during whole body vibration: effect of frequency and amplitude. Clin Biomech. 2010;25(8):840–846. doi:10.1016/j.clinbiomech.2010.05.004

24.

Cardinale

Bosco

. The use of vibration as an exercise intervention. Exerc Sport Sci Rev. 2003;31(1):3–7. doi:10.1097/00003677-200301000-00002

25.

Esmaeilzadeh

Akpinar

Polat

Yildiz

Oral

. The effects of two different frequencies of whole-body vibration on knee extensors strength in healthy young volunteers: a randomized trial. J Musculoskelet Neuronal Interact. 2015;15(4):333–340.

26.

Lukaski

. Methods for the assessment of human body composition: traditional and new. Am J Clin Nutr. 1987;46(4):537–556. doi:10.1093/ajcn/46.4.537

27.

Lazzer

Bedogni

Agosti

De Col

Mornati

Sartorio

. Comparison of dual-energy X-ray absorptiometry, air displacement plethysmography and bioelectrical impedance analysis for the assessment of body composition in severely obese Caucasian children and adolescents. Br J Nutr. 2008;100(4):918–924. doi:10.1017/S0007114508922558

28.

Wilson

Jones

. Long-term reproducibility of Borg scale estimates of breathlessness during exercise. Clin Sci. 1991;80(4):309–312. doi:10.1042/cs0800309

29.

Sartorio

Lafortuna

Conte

Faglia

Narici

. Changes in motor control and muscle performance after a short-term body mass reduction program in obese subjects. J Endocrinol Invest. 2001;24(6):393–398. doi:10.1007/BF03351039

30.

Sartorio

Narici

Fumagalli

Faglia

Lafortuna

. Aerobic and anaerobic performance before and after a short-term body mass reduction program in obese subjects. Diabetes Nutr Metab. 2001;14(1):51–57.

31.

Sartorio

Proietti

Marinone

Agosti

Adorni

Lafortuna

. Influence of gender, age and BMI on lower limb muscular power output in a large population of obese men and women. Int J Obes Relat Metab Disord. 2004;28(1):91–98. doi:10.1038/sj.ijo.0802433

32.

Lazzer

Bravo

Tringali

De Micheli

De Col

Sartorio

. A 3-week multidisciplinary body weight reduction program improves body composition and lower limb power output in 3,778 severely obese children and adolescents. Front Physiol. 2020;11:548. doi:10.3389/fphys.2020.00548

33.

Chen

C-N

Chuang

L-M

Y-T

. Clinical measures of physical fitness predict insulin resistance in people at risk for diabetes. Phys Ther. 2008;88(11):1355–1364. doi:10.2522/ptj.20080064

34.

Perret

Poiraudeau

Fermanian

Colau

Benhamou

Revel

. Validity, reliability, and responsiveness of the fingertip-to-floor test. Arch Phys Med Rehabil. 2001;82(11):1566–1570. doi:10.1053/apmr.2001.26064

35.

Curtis

Chughtai

Khlopas

, et al.

Impact of physical activity in cardiovascular and musculoskeletal health: can motion be medicine?

J Clin Med Res. 2017;9(5):375–381. doi:10.14740/jocmr3001w

36.

Kachur

Lavie

de Schutter

Milani

Ventura

. Obesity and cardiovascular diseases. Minerva Med. 2017;108(3):212–228. doi:10.23736/S0026-4806.17.05022-4

37.

Maffiuletti

Jubeau

Munzinger

, et al. Differences in quadriceps muscle strength and fatigue between lean and obese subjects. Eur J Appl Physiol. 2007;101(1):51–59. doi:10.1007/s00421-007-0471-2