
==== Front
J Phys Ther Sci
J Phys Ther Sci
JPTS
Journal of Physical Therapy Science
0915-5287
2187-5626
The Society of Physical Therapy Science

2024-051
10.1589/jpts.36.488
Original Article
Influence of exercise using the Valsalva maneuver on vital signs in young adults
Chigira Yusuke PhD 1 *
Hayakawa Tomomi RPT 2
Saida Kosuke RPT 1
Takeuchi Nobuyuki PhD 1
1) Department of Physical Therapy, Graduate School of Health Science, Takasaki University of Health and Welfare: 501 Nakaoorui, Takasaki-shi, Gunma 370-0033, Japan
2) Department of Rehabilitation, Tokyo Medical University Ibaraki Medical Center, Japan
* Corresponding author. Yusuke Chigira (E-mail: chigira@takasaki-u.ac.jp)
5 9 2024
9 2024
36 9 488491
01 5 2024
27 5 2024
2024©by the Society of Physical Therapy Science. Published by IPEC Inc.
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives (by-nc-nd) License. (CC-BY-NC-ND 4.0: https://creativecommons.org/licenses/by-nc-nd/4.0/)
[Purpose] To examine the influence of exercise using the Valsalva maneuver on vital signs. [Participants and Methods] Twenty-five healthy university students participated in the study. All participants were instructed to perform the squat under two loading intensities, that is, with barbell weights of 40% and 80% of body weight, under two conditions: no breath-holding (Control group) and breath-holding (Valsalva group). Blood pressure, pulse pressure, lactic acid level, and Borg scale scores were measured before and after each exercise session. [Results] Systolic blood pressure, mean blood pressure, and pulse pressure increased in the 80% Control, 40% Valsalva, and 80% Valsalva groups. [Conclusion] The use of the Valsalva maneuver could influence the vital signs of young, healthy participants.

Young individuals
Valsalva maneuver
Vital signs
==== Body
pmcINTRODUCTION

In the scene of physical therapy, the expression “Don’t stop breathing” is often heard during strength training or guidance for activities of daily living (ADL). This is because breath holding may increase the blood pressure, exacerbating the disease1). However, a study indicated that the use of the Valsalva maneuver for strength training improved the muscle strength2).

The mechanism of increased blood pressure has been explained by the Valsalva phenomenon3). The absence of breath holding during physical therapy for patients with cardiovascular disease or elderly persons is important from the viewpoint of risk management.

The prevention of breath holding-related Valsalva phenomenon is emphasized as a method of risk management. However, no study has investigated changes in vital signs other than blood pressure during exercise with breath holding in detail. A study reported the relationship between the duration of breath holding (seconds) and blood pressure4), but short-time breath holding on exertion or defecation is often experienced rather than the scene of simple breath holding in daily living. In the scene of physical therapy, breathing may also be stopped in a short time during muscle strength-enhancing exercise or ADL. A study reported Valsalva-maneuver-related changes in the heart rate and blood pressure in young persons5), but the data do not reflect changes during exercise therapy such as strength training. Furthermore, no study has examined the influence on vital signs other than blood pressure, such as the lactic acid level or oxygen intake.

The purpose of this study was to examine the influence on vital signs during strength training, as an item of exercise therapy, with respect to the presence or absence of the Valsalva maneuver. Furthermore, we established the intensity of exercise as low and high (40 and 80% of the body weight, respectively), and investigated changes in vital signs related to the difference in the intensity of exercise.

PARTICIPANTS AND METHODS

The participants were 25 healthy male university students who had done exercise at senior high school and consented to participate in this study (age: 21 to 24 years, height: 167 ± 4.69 cm, body weight: 62.2 ± 6.9 kg) (Table 1Table 1. Participants characteristics

Participants n (male)	25	
Age (years)	21.28 ± 1.13	
Height (cm)	167.0 ± 4.69	
Weight (kg)	62.2 ± 6.91	
BMI (kg/m2)	22.35 ± 1.58	
BMI: body mass index.

). The exclusion criteria included those with orthopedic or heart diseases.

Concerning ethical considerations, the purpose and contents of this study were explained to the participants in writing and verbally in advance, and they were instructed to sign the consent form before this study. Furthermore, the following rule was set in consideration with safety: measurement may be discontinued if there is a change in the condition or if the participant wishes to drop out of this study. The following points were also determined: each participant should cooperate with this study based on his free will, and there will be no disadvantage even if the participant does not cooperate or even if participation in this study is discontinued. This study was conducted while paying much attention to the protection of each participants’ information according to the Helsinki Declaration. This study was approved by the Ethics Committee of Kan-etsu Chu-oh Hospital (Approval No.: 20220424).

The following devices were used for this study: a barbell (iROTEC, Osaka, Japan), a manual electronic blood pressure monitor (Digital Blood Pressure Monitor UA-704: A&D Company, Limited, Tokyo, Japan), exhalation-gas analyzer (Cpex-1: Inter Reha Co., Ltd., Tokyo, Japan), bicycle ergometer (AESROBIKE75XLIII: COMBI, Tokyo, Japan), simple blood lactate meter (Lactate Pro TM2LT-1730: ARKRAY, Inc., Kyoto, Japan), and puncture device (Naturalet petit: ARKRAY, Inc.).

The participants were instructed to do squat exercises with barbells. Two conditions were established: no breath holding (each participant was instructed not to hold his breath) (Control condition) and breath holding by straining under increased abdominal pressure (Valsalva condition). Furthermore, two load conditions (barbell weights) were established as 40 and 80% of the body weight.

Exercise was done under four conditions: 40% Control, 80% Control, 40% Valsalva, and 80% Valsalva conditions. The participants were instructed to meet the 4 intervention conditions at ≥3-day intervals. The order of intervention was randomly established through lottery drawing.

The position of the shaft on squatting was set at the superior border of scapula, the direction of toes as parallel, and the stance width as the shoulder width. The most descended height was set so that the floor might be parallel to the femur. The interval from Phase 1 to Phase 3 was set as two seconds, and that from Phase 3 to Phase 1 as two seconds. The frequency of squatting was established as 10 times. Concerning respiration during squat exercise in the Control group, each participant was instructed to exhale from the start of motion in Phase 1 until returning to Phase 1 via Phase 3. In the Valsalva group, each participant was instructed to hold his breath for 4 seconds during the squat exercise and breathe on returning to Phase 1 (Fig. 1Fig. 1. Method in the Valsalva group.

). The systolic blood pressure, heart rate, and lactic acid levels were measured before and after exercise under each condition. Furthermore, oxygen intake for 1 minute after exercise was analyzed/measured using a Cpex-1 system.

The systolic blood pressure and heart rate were measured before the start of exercise and immediately after its completion. The lactic acid level was measured before the start of exercise and 1 minute after its completion. Concerning oxygen intake, the maximum oxygen intake in 1 minute after the completion of the exercise was used.

To compare the values before and after exercise intervention under each condition, Wilcoxon’s signed-rank sum test was performed. To compare the values between the Control and Valsalva conditions, Wilcoxon’s signed-rank sum test was conducted. To compare maximum oxygen intake in 1 minute after exercise, Friedman’s test was performed. For subsequent multiple comparison, Wilcoxon’s signed-rank sum test was conducted using Bonferroni’s inequality correction. We used SPSS Statistics (version 17.0, IBM, Armonk, NY, USA) software. A p-value of 0.05 was regarded as significant.

RESULTS

The values before and after exercise under each condition were compared. There were significant differences in the systolic blood pressure in the 80% Control, 40% Valsalva, and 80% Valsalva groups. There were significant differences in the heart rate and lactic acid level regardless of the conditions (Table 2Table 2. Changes before and after exercise

	Systolic blood pressure (mmHg)	Heart rate (bpm)	Lactic acid (mmol/L)	
			
Before exercise	After exercise	Before exercise	After exercise	Before exercise	After exercise	
40% Control condition	114.44 ± 8.47	120.44 ± 12.07	80.01 ± 14.10	118.82 ± 11.03**	1.18 ± 0.31	2.49 ± 0.97**	
80% Control condition	113.64 ± 12.18	126.96 ± 14.40**	79.04 ± 11.38	126.12 ± 14.35**	1.34 ± 0.30	3.15 ± 1.14**	
40% Valsalva condition	112.28 ± 20.9	127.52 ± 12.21**	70.12 ± 5.73	118.36 ± 6.55**	1.39 ± 0.39	2.85 ± 0.83**	
80% Valsalva condition	118.64 ± 10.50	133.88 ± 8.42**	74.96 ± 10.67	123.72 ± 9.89**	1.28 ± 0.31	3.13 ± 1.33**	
Mean ± standard deviation. **: p<0.01, *: p<0.05.

).

Furthermore, the amount of change was compared between the Control and Valsalva conditions. There were significant differences in the systolic blood pressure and heart rate between the 40% Control and Valsalva conditions. Furthermore, there was a significant difference in the lactic acid level between the 80% Control and Valsalva conditions (Table 3Table 3. Comparison of the amount of change related to exercise in the Control and Valsalva groups

	Systolic blood pressure (mmHg)	Heart rate (bpm)	Lactic acid (mmol/L)	
			
Control condition	Valsalva condition	Control condition	Valsalva condition	Control condition	Valsalva condition	
40% load	7.28 ± 6.58	12.96 ± 5.53**	34.80 ± 7.64	48.24 ± 8.48**	1.38 ± 0.74	1.54 ± 1.01	
80% load	13.32 ± 12.06	15.24 ± 19.28	47.08 ± 11.83	48.76 ± 13.73	1.81 ± 1.19	2.15 ± 1.18*	
Mean ± standard deviation. **: p<0.01, *: p<0.05.

).

The maximum oxygen intake in 1 minute after exercise was compared. There were significant differences between the 40% Control and 40% Valsalva conditions, between the 40% Control and 80% Valsalva conditions, and between the 80% Control and 80% Valsalva conditions (Table 4Table 4. PeakVO2 in 1 minute after exercise

	40% Control condition	80% Control condition	40% Valsalva condition	80% Valsalva condition	
PeakVO2 (mL/kg/min)	28.84 ± 4.40	30.25 ± 3.96	34.53 ± 8.28a	35.36 ± 6.25a, b	
Mean ± standard deviation.

The results of Wilcoxon’s signed-rank sum test with Bonferroni’s inequality correction.

ap<0.05 / 6=0.0083: comparison with the value on 40% Control condition.

bp<0.05 / 6=0.0083: comparison with the value on 80% Control condition.

).

DISCUSSION

We established the Control and Valsalva conditions and examined their influence on vital signs during exercise under loads corresponding to 40 and 80% of the body weight.

When focusing on the systolic blood pressure, there was no significant difference after exercise in comparison with the pre-exercise value under the 40% Control condition. However, there was a significant difference under the 40% Valsalva condition. The systolic blood pressure increased by 6.0 mmHg on average after exercise under the 40% Control condition, whereas it increased by 15.24 mmHg on average under the 40% Valsalva condition. There was also a significant difference in the amount of change. As the reason why there was a significant difference between the 40% Control and 40% Valsalva conditions, the influence of the Valsalva maneuver is suggested. As the mechanism of a Valsalva-maneuver-related increase in blood pressure, the intrathoracic pressure may increase through breath holding and hinder venous return, inducing reflex tachycardia and an increase in peripheral vascular resistance via baroreceptors and increasing the blood pressure6). The results of this study showed that straining induced the Valsalva phenomenon even under a load at which there is no increase in the blood pressure in the absence of breath holding (if the participant is instructed not to strain or stop breathing), increasing the blood pressure.

On the other hand, there were significant differences in the systolic blood pressure, heart rate, and lactic acid level after exercise in comparison with the pre-exercise values under the 80% Control and 80% Valsalva conditions.

The systolic blood pressure increased by 13.32 mmHg on average after exercise in the 80% Control group and by 15.24 mmHg in the 80% Valsalva group. There was no significant difference in the amount of change.

The rate of increase in blood pressure in the 80% Control group was greater than in the 40% Control group. This was possibly because the load was higher and because there was an increase in the muscular blood flow volume. Factors for changes in the systolic blood pressure include increases in the heart rate and cardiac output. High-intensity exercise may have increased the blood flow volume required for muscles, increasing cardiac and pulmonary blood flow for compensation and, thus, elevating the blood pressure through blood-flow-increasing actions such as an increase in the heart rate7).

The reason why there were no significant differences in the systolic blood pressure or heart rate between the 80% Control and 80% Valsalva conditions, a load corresponding to 80% of the body weight may have increased the heart rate and stroke volume in the absence of straining; the influence of the Valsalva phenomenon was not found. Concerning the lactic acid level, high-intensity exercise (80% load) promotes the production of lactic acid, and a large amount of lactic acid may have been produced through Valsalva effects.

Concerning the maximum oxygen intake in 1 minute after exercise, even when the same load was adopted, the maximum oxygen intake may have markedly increased to compensate for a greater oxygen deficit related to breath holding and straining under the Valsalva condition.

This study clarified the influence of the Valsalva maneuver on vital signs in young persons with a potent vasodilative ability8). It was shown that even low-intensity exercise without blood-pressure elevation significantly increased the blood pressure in the presence of breath holding, suggesting the risk of the Valsalva maneuver in patients with cardiovascular disease or elderly persons with vasodilative hypofunction.

In this study, squatting was performed as a movement task. However, the value of increased blood pressure in the ADL scene may be clarified by establishing the motion of lifting heavy luggage or that on defecation as tasks and investigating them. Furthermore, it may be possible to examine the influence of the Valsalva maneuver related to the difference in the vasodilative ability by comparing the results between young and elderly persons. In the future, the influence of the Valsalva maneuver on vital signs should be further investigated.

We examined the influence of exercise with the Valsalva maneuver on vital signs in young persons. We reconfirmed that, even when doing low-intensity exercise, it was important to attract attention so that there might be no breath holding, and that high-intensity exercise influenced vital signs; caution is needed. In the scene of physical therapy, it is important to attract attention with the expression “Let’s do it without holding your breath” during muscle-strength-enhancing exercise or ADL guidance. In particular, such risk management may be important for patients with cardiovascular disease or elderly persons.

Conflict of interest

The authors have no conflicts of interests to disclose.
==== Refs
REFERENCES

1 Looga R : The Valsalva manoeuvre—cardiovascular effects and performance technique: a critical review. Respir Physiol Neurobiol, 2005, 147 : 39–49. 15848122
2 Altherr CA Soave KM Nagelkirk PR et al. : The influence of a total body resistance training program on autonomic modulation and strength variables in young adults. Int J Exerc Sci, 2021, 14 : 802–814. 34567354
3 American College of Sports Medicine: ACSM guidelines for exercise testing and prescription. Baltimore: Williams & Wilkins, 2000.
4 Looga R : The bradycardic response to the Valsalva manoeuvre in normal man. Respir Physiol, 2001, 124 : 205–215. 11173075
5 Randall EB Billeschou A Brinth LS et al. : A model-based analysis of autonomic nervous function in response to the Valsalva maneuver. J Appl Physiol, 2019, 127 : 1386–1402. 31369335
6 Drury K Green S : Effects of intensity and training on cardiovascular responses to the Valsalva maneouvre. J Basic Clin Physiol Pharmacol, 2022, 34 : 111–119. 36351198
7 Levin AB : A simple test of cardiac function based upon the heart rate changes induced by the Valsalva maneuver. Am J Cardiol, 1966, 18 : 90–99. 5938917
8 Saldaña García J Torremocha López A Dawid Milner MS : Influence of repetitions on the Valsalva maneuver. Clin Neurophysiol Pract, 2020, 5 : 104–111. 32518858
