Acute effects of isometric plank exercise on 24-hour ambulatory blood pressure in young adults with prehypertension: a randomized cross-over trial

Abstract

Background

Isometric resistance exercise has been shown to reduce blood pressure (BP), particularly when involving large muscle groups. Isometric plank exercise (IPE), which elicits extensive muscle activation, may offer similar benefits; however, its acute effects on ambulatory blood pressure monitoring (ABPM) and variability remain unclear. This study aimed to examine the acute effects of IPE on ABPM, blood pressure variability (BPV) and ambulatory arterial stiffness index (AASI) in young adults with prehypertension.

Methods

Twelve young adults (mean age, 26.4 ± 5.4 years) with prehypertension (systolic BP [SBP] 120–139 mmHg or diastolic BP [DBP] 80–89 mmHg) participated in a randomized cross-over trial. Each participant completed 2 sessions in random order: 1) 4 × 2-minute IPE session with 1-minute rest, and 2) a non-exercise control session. Office BP was measured at baseline, 30 minutes, and 90 minutes post-trial. ABPM, BPV and AASI were recorded over the following 24 hours.

Results

A significant interaction effect was observed for systolic office BP (P = 0.009), with post-hoc analysis revealing a significant reduction at 90 minutes post-IPE session (P = 0.048). Twenty-four-hour average systolic and DBP were significantly lower in the IPE session compared to control session (P = 0.004, P = 0.031, respectively). In addition, both daytime SBP (P = 0.020) and nighttime DBP (P = 0.014) significantly decreased after the IPE session. Nighttime systolic BPV was also significantly decreased after the IPE session (P = 0.040). No significant changes were observed in other BPV index and AASI.

Conclusions

IPE significantly reduced 24-hour SBP and DBP and improved nighttime BP variability in young adults with prehypertension. These findings provide preliminary evidence that IPE may serve as a potential nonpharmacologic strategy for early BP management. Large-scale interventional studies are warranted to confirm and extend on these effects.

Graphical Abstract

BACKGROUND

Hypertension (HTN) is one of the most pressing global public health issues and is recognized as a major precursor to cardiovascular disease (CVD) [1]. Prehypertension is associated with a substantially increased risk of progressing to HTN and CVD complications, necessitating early intervention [2]. In individuals with prehypertension, lifestyle modifications are recommended as the primary strategy rather than pharmacologic treatment, and among these, exercise is widely endorsed as an effective nonpharmacologic intervention for managing blood pressure (BP) and reducing CVD risk [3,4].

Aerobic exercise is a well-established approach for preventing and treating HTN, with current guidelines recommending 150 to 300 minutes of moderate-intensity exercise per week. However, its BP-lowering effects in young adults with prehypertension or HTN remain debated [5]. Moreover, barriers such as limited access to exercise facilities, time constraints, and low adherence contribute to reduced exercise participation [6]. Therefore, there is a growing need for practical and sustainable exercise strategies to complement aerobic activity and improve BP control in this population.

Resistance exercise has emerged as an effective alternative strategy for BP management [7]. Among its modalities, isometric resistance exercise—characterized by sustained muscle contraction without changes in muscle length—has attracted growing interest due to its feasibility and minimal equipment requirements. Recent meta-analyses have shown that while aerobic exercise can reduce systolic blood pressure (SBP) by approximately 5–8 mmHg, isometric handgrip exercise may lead to reductions of 8–10 mmHg, and lower-limb isometric exercises such as wall squats and knee extensions have demonstrated even greater hypotensive effects up to 10–12 mmHg [8,9]. These findings suggest that isometric exercise may induce greater BP reductions compared to aerobic modalities, reinforcing its role as a promising intervention for HTN prevention and control.

Moreover, the magnitude of the hypotensive response may be related to the amount of muscle mass activated [10]. Isometric exercise encompasses a range of modalities, and the effects of various isometric movement types on BP remain underexplored [11]. While handgrip protocols are well-documented, other forms—particularly those involving larger muscle groups, such as isometric squats or planks—require further investigation to establish their efficacy and physiological mechanisms [12].

Plank exercise, a popular contemporary training modality, is a full-body isometric exercise that requires simultaneous contraction of multiple large muscle groups, distinguishing it from localized isometric exercises such as handgrip and wall squat protocols [13]. Given evidence suggesting that greater muscle mass engagement during isometric contraction leads to more pronounced reductions in BP [14], plank exercise may offer similar or even superior hypotensive effects. Similar to isometric handgrip exercise, which recruits a small forearm muscle mass affecting regional blood flow and shear stress, engaging multiple large muscle groups with plank exercise is expected to augment systemic blood flow and vascular shear stress, thereby stimulating endothelial nitric oxide synthase (eNOS) and increasing nitric oxide (NO) bioavailability [15,16], important mediators of BP reduction with exercise. Recently, European Society of Cardiology guideline formally included isometric plank exercise (IPE) as a recommended modality for lowering BP [17]. However, there is a notable lack of research examining the acute effects of IPE on BP regulation, particularly in young adults with prehypertension.

To more accurately assess the effects of exercise interventions, it is essential to employ 24-hour ambulatory blood pressure monitoring (ABPM) rather than relying solely on clinic-based BP measurements [18]. ABPM allows for the continuous tracking of BP throughout daily life and provides separate measurements for daytime and nighttime periods [19]. Moreover, ABPM enables the evaluation of blood pressure variability (BPV), which has emerged as an independent risk factor for cardiovascular events [20,21]. In addition to BPV, ambulatory arterial stiffness index (AASI), which is both a measure of BPV and an indirect measure of arterial stiffness, has also been associated with target organ damage in hypertensive patients [22,23]. As most previous studies on isometric exercise have focused on clinic-based BP measurements, this study aimed to investigate the acute effects of IPE on 24-hour ABPM, BPV and AASI in young adults with prehypertension.

METHODS

Participants

Twelve young adults (9 males and 3 females) with prehypertension participated in this study, which employed a randomized cross-over design in which each participant completed both an IPE session and a control session. Eligibility was determined based on a screening questionnaire and clinical assessments. Inclusion criteria were as follows: adults aged 19 to 39 years with a SBP of 120–139 mmHg or a diastolic blood pressure (DBP) of 80–89 mmHg. Exclusion criteria included any history of cardiovascular, musculoskeletal, metabolic, inflammatory, or respiratory diseases; current use of medications related to these conditions; and any medical or physical limitations to exercise participation. Prehypertension status was confirmed by averaging 2 BP measurements taken after 10 minutes of supine rest in a quiet laboratory environment. Medical history and exercise readiness were further evaluated using a basic medical questionnaire and the Physical Activity Readiness Questionnaire. Participants meeting any of the exclusion criteria were excluded from the study.

Study design and procedures

Participants were randomly assigned to complete 2 experimental conditions: (1) an IPE session and (2) a non-exercise control session, in a randomized cross-over design. A minimum washout period of 3 days (72 hours) was observed between sessions to avoid carryover effects. To further address potential order or carryover effects, sequence-stratified analyses were conducted and are presented in the Supplementary Fig. 1. Each trial began at 10:00 AM, and participants were fitted with a 24-hour ABPM one hour prior to the start of the experimental session. Following the session, participants were instructed to resume their normal daily activities until the device was removed at 10:00 AM the following day. To minimize measurement variability, participants were advised to refrain from vigorous exercise within the preceding 24 hours, abstain from alcohol, caffeine, and smoking, and to fast for at least 8 hours prior to each session.

Isometric plank and control conditions

The IPE protocol was based on the posture described by Park et al. [24]. Participants performed the plank while maintaining a neutral spine alignment from head to toe, with shoulders and elbows flexed at 90 degrees, and eyes directed toward the floor (Fig. 1). The intervention consisted of 4 sets of 2-minute isometric planks, with 1-minute rest intervals between sets. Throughout the session, heart rate was continuously monitored using a wrist-worn device (Fitbit Charge 2; Fitbit Inc., San Francisco, CA, USA), and perceived exertion was assessed using the Borg Category-Ratio 10 Scale. If a participant’s rating of perceived exertion exceeded 8, they were allowed to briefly rest by placing their knees on the ground, but were encouraged to resume the plank position as soon as possible.

Fig. 1. Isometric plank exercise position applied in the experimental condition.

In the control condition, participants visited the laboratory at the same time of day and remained seated in a resting position for a duration equal to that of the exercise session. To minimize external influences on BP, participants were instructed to refrain from consuming caffeine, watching stimulating media, or engaging in games or other activating tasks during the control period.

Measurements

Ambulatory blood pressure (ABP) was measured using an automated oscillometric device (Mobil-O-Graph; IEM, Aachen, Germany) placed on the upper arm. In both the isometric plank and control conditions, monitoring began one hour prior to the intervention (10:00 AM) and continued for 24 hours. During this period, BP was automatically recorded at 30-minute intervals throughout the daytime and nighttime. Collected BP values were processed by averaging the readings taken on the hour and at 30 minutes past the hour. Outlier values were replaced with the mean of the adjacent time points. For analysis, BP was categorized as 24-hour mean BP, daytime BP (10:00 AM to 9:00 PM), and nighttime BP (1:00 AM to 6:00 AM). These fixed-clock intervals were chosen to reflect sleep-wake patterns of the participants enrolled in our study and to minimize misclassifying late-evening wakefulness and early-morning sleep. BPV was assessed using the average real variability (ARV) method, as described by Mena et al. [25]. ARV was calculated using the formula: $\mathrm{A}\mathrm{R}\mathrm{V}\mathrm{ }=\mathrm{ }(1\mathrm{ }/\mathrm{ }(\mathrm{N}\mathrm{ }-\mathrm{ }1\left)\right)\mathrm{ }\times \mathrm{ }\mathrm{\Sigma }\mathrm{ }|{\mathrm{B}\mathrm{P}}_{{\mathrm{k}}^{+1}}\mathrm{ }-\mathrm{ }{\mathrm{B}\mathrm{P}}_{\mathrm{k}}|$, where N represents the number of valid BP readings, and BP_k is the BP at each time point. This metric reflects the average absolute difference between consecutive measurements and is considered a robust indicator of real BP variability. In addition to BP and ARV, arterial stiffness and BP variability were further evaluated using AASI and blood pressure variability ratio (BPVR). The original AASI (standard) was calculated as 1 − the regression slope of DBP on SBP using 24-hour ABPM data. For this, linear regression was performed with DBP as the dependent variable and SBP as the independent variable. AASI (BPVR) was derived as 1 – 1/BPVR, where BPVR was defined as the ratio of the standard deviation (SD) of SBP to that of DBP (i.e., SD(SBP)/SD(DBP)). These indices were calculated separately for each condition and compared to evaluate acute changes in arterial stiffness and pressure variability following IPE.

Sample size calculation and statistical analysis

Sample size was estimated using G*Power 3.1 software based on a repeated-measures analysis of variance (ANOVA) design with a within-between interaction. With an assumed effect size of f = 0.25, significance level (α) of 0.05, and statistical power of 0.80, 3 repeated measurements and a correlation among repeated measures of ρ = 0.60, the minimum required sample size was calculated to be 24 participants. However, because this study employed a randomized cross-over design in which each participant completed both conditions, a total sample of 12 participants was deemed sufficient.

All continuous data are presented as mean ± standard deviation in the text and tables. Fig. 3 is presented as box-and-whisker plots with medians and interquartile ranges, with individual data points overlaid. The level of statistical significance was set at P ≤ 0.05. Statistical analyses were performed using SPSS version 28.0 (SPSS Inc., Chicago, IL, USA). Office BP was analyzed using a 2-way repeated-measures ANOVA (2 × 3), with time (pre-exercise, post-exercise, and 90 minutes post-exercise) as the within-subject factor and condition (plank vs. control) as the between-condition factor. Post hoc comparisons were conducted using the Bonferroni correction. Differences between the plank and control conditions for 24-hour, daytime, and nighttime ambulatory BP, BPV (ARV), and arterial stiffness indices [AASI (standard), AASI (BPVR), and BPVR] were analyzed using paired t-tests.

Fig. 3. Effects of study conditions on 24-hour ambulatory blood pressure: SBP (A) and DBP (B). Data are presented as box-and-whisker plots (line = median, box = interquartile range, whiskers = minimum and maximum) with individual data points overlaid for 24-hour, daytime, and nighttime ambulatory blood pressure after plank and control conditions.

SBP, systolic blood pressure; DBP, diastolic blood pressure.

^*P < 0.05 indicates significant difference between conditions.

RESULTS

All 12 participants completed both the isometric plank and control conditions without dropout.

Sequence-stratified analyses confirmed that BP responses were highly comparable regardless of randomization order, indicating no meaningful carryover effects (Supplementary Fig. 1). Baseline characteristics of the participants are presented in Table 1. The mean age was 26.4 ± 5.4 years, and all participants met the criteria for prehypertension, defined as a SBP of 120–139 mmHg or a DBP of 80–89 mmHg.

Table 1. Baseline characteristics of participants (n = 12).

Variables		Values (mean ± SD)
Sex (males/females)		9/3
Age (yr)		26.4 ± 5.4
Height (cm)		175.2 ± 9.3
Weight (kg)		73.6 ± 10.5
BMI (kg/m2)		23.9 ± 2.3
Resting HR (beats/min)		74.0 ± 8.7
24-hr (mmHg)
	SBP	124.3 ± 9.9
	DBP	78.5 ± 6.3
	MAP	93.8 ± 6.7
Daytime (mmHg)
	SBP	129.4 ± 9.7
	DBP	83.6 ± 6.6
	MAP	98.8 ± 6.3
Nighttime (mmHg)
	SBP	115.7 ± 10.9
	DBP	69.2 ± 7.3
	MAP	84.7 ± 7.9
Office (mmHg)
	SBP	129.1 ± 10.8
	DBP	85.6 ± 7.2
	MAP	100.1 ± 5.7

BMI, body mass index; HR, heart rate; SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure.

A significant interaction effect was observed for systolic office BP (interaction effect: P = 0.009). Post hoc analysis revealed a significant reduction in SBP at 90 minutes post-plank exercise (P = 0.048). No significant interaction or time effects were found for diastolic office BP (P = 0.238; Fig. 2).

Fig. 2. Effects of study conditions on office blood pressure: SBP (A) and DBP (B).

SBP, systolic blood pressure; DBP, diastolic blood pressure.

^*P < 0.05 indicates a significant difference between conditions at the same time point.

The 24-hour average SBP was significantly lower in the plank condition (122.2 ± 9.6 mmHg) compared to the control condition (126.4 ± 10.2 mmHg, P = 0.004). Similarly, the 24-hour average DBP was significantly reduced in the plank condition (77.1 ± 5.7 mmHg) relative to the control condition (79.9 ± 6.9 mmHg, P = 0.031). Nighttime SBP showed a non-significant trend toward reduction in the plank condition (113.1 ± 8.4 mmHg) compared to control (115.8 ± 10.7 mmHg, P = 0.266), whereas nighttime DBP was significantly lower following the plank exercise (66.6 ± 6.1 mmHg vs. 71.7 ± 8.0 mmHg, P = 0.014). Daytime SBP was also significantly lower in the plank condition (127.1 ± 9.8 mmHg) compared to the control condition (131.7 ± 9.5 mmHg, P = 0.020), while daytime DBP showed no significant difference between conditions (Table 2, Fig. 3).

Table 2. Comparison of ambulatory blood pressure, blood pressure variability and arterial stiffness indices between plank and control conditions.

Variables	Plank	Control	Mean difference (Δ)	P-value
24-hr SBP (mmHg)	122.2 ± 9.6*	126.4 ± 10.2	−4.3 ± 4.1	0.004
Daytime SBP (mmHg)	127.1 ± 9.8*	131.7 ± 9.5	−4.6 ± 5.9	0.020
Nighttime SBP (mmHg)	113.1 ± 8.4	115.8 ± 10.7	−2.7 ± 7.6	0.266
24-hr DBP (mmHg)	77.1 ± 5.7*	79.9 ± 6.9	−2.8 ± 4.0	0.031
Daytime DBP (mmHg)	82.0 ± 5.6	85.2 ± 7.4	−3.2 ± 5.9	0.092
Nighttime DBP (mmHg)	66.6 ± 6.1*	71.7 ± 8.0	−5.1 ± 6.2	0.014
24-hr SARV (mmHg)	7.2 ± 1.8	8.4 ± 2.2	−1.2 ± 2.6	0.172
Daytime SARV (mmHg)	7.0 ± 2.0	7.1 ± 2.7	−0.1 ± 2.8	0.883
Nighttime SARV (mmHg)	8.5 ± 3.9*	11.9 ± 5.1	−3.4 ± 4.8	0.040
24-hr DARV (mmHg)	7.3 ± 4.5	7.5 ± 1.3	−0.2 ± 2.3	0.765
Daytime DARV (mmHg)	6.0 ± 1.6	6.7 ± 1.7	−0.7 ± 1.8	0.223
Nighttime DARV (mmHg)	8.4 ± 3.5	9.7 ± 3.9	−1.2 ± 3.2	0.227
24-hr AASI (standard)	0.29 ± 0.40	0.33 ± 0.20	−0.03 ± 0.30	0.681
AASI (BPVR)	0.59 ± 0.30	0.58 ± 0.20	0.00 ± 0.20	0.972
BPVR	1.23 ± 0.60	1.13 ± 0.30	0.10 ± 0.40	0.449

SBP, systolic blood pressure; DBP, diastolic blood pressure; SARV, systolic average real variability; DARV, diastolic average real variability; AASI, ambulatory arterial stiffness index; BPVR, blood pressure variability ratio.

^*P < 0.05 vs. control.

For BPV, the 24-hour systolic ARV was lower in the plank condition (7.2 ± 1.8 mmHg) compared to the control condition (8.4 ± 2.2 mmHg), though the difference was not statistically significant (P = 0.172). Diastolic ARV also showed no significant difference between conditions (P = 0.765). Notably, nighttime systolic ARV was significantly lower in the plank condition (8.5 ± 3.9 mmHg) compared to control (11.9 ± 5.1 mmHg, P = 0.040). No significant changes were observed in daytime or nighttime diastolic ARV (Table 2).

AASI and BPV indices were compared between the 2 conditions (Table 2). No significant difference was observed in 24-hour AASI (standard) between the plank (0.29 ± 0.4) and control conditions (0.33 ± 0.2, P = 0.681). Similarly, AASI (BPVR) values were nearly identical in both conditions (plank: 0.59 ± 0.3 vs. control: 0.58 ± 0.2, P = 0.972). The BPVR also showed no significant difference (plank: 1.23 ± 0.6 vs. control: 1.13 ± 0.3, P = 0.449).

DISCUSSION

This study investigated the acute effects of IPE on 24-hour ABPM and BPV (ARV) in young adults with prehypertension. The findings revealed a modest but clinically meaningful reduction in SBP at 90 minutes post-exercise, suggesting a short-term hypotensive response. These results highlight the potential of full-body isometric exercise as a non-pharmacological strategy for acute BP management. Although previous studies on localized isometric modalities, such as handgrip training, have shown inconsistent outcomes [26], the larger muscle mass engagement during plank exercise may have contributed to the favorable BP response observed in this study. However, direct comparisons across isometric modalities were not made, and future studies are needed to clarify their relative efficacy.

Notably, both 24-hour average systolic and diastolic BP were significantly lower following the plank session compared to the control condition. This finding suggests that IPE may positively influence BP regulation across a full day, beyond short-term post-exercise effects. These results contrast with previous studies of isometric handgrip exercise, in which 24-hour ambulatory BP did not show significant reductions [27]. A key distinction may lie in the nature of the plank exercise, which involves isometric contraction of both upper and lower body musculature, thereby recruiting a larger total muscle mass. Supporting this interpretation, greater muscle mass engagement during isometric exercise is associated with enhanced BP-lowering effects [14]. Thus, the more extensive muscular activation elicited by the plank may have contributed to the greater overall reduction in 24-hour ambulatory BP observed in this study.

In addition to reductions in 24-hour average systolic and diastolic BP, the present study also found a significant decrease in night DBP following the plank session. Although nighttime SBP showed a downward trend, the difference did not reach statistical significance. Nighttime BP may be a stronger predictor of CVD risk than daytime BP [28]. Moreover, a reduction of 5 mmHg in nighttime BP is associated with a 17% reduction in CVD risk [29]. Therefore, the observed reduction in nighttime BP following IPE may contribute not only to improved daily BP control but also to a meaningful reduction in long-term CVD risk. Moreover, a significant reduction was observed in daytime SBP, which has been reported to be independently associated with cardiovascular events [30]. While some studies have emphasized the superior prognostic power of nighttime BP, daytime SBP also significantly predicted cardiovascular mortality and stroke [31]. This suggests that reductions in daytime SBP even from a single bout of IPE may have meaningful prognostic value.

The observed BP-lowering effects of plank exercise may be partially explained by the underlying physiological mechanisms of isometric exercise. During isometric contraction, mechanical compression of the vasculature within the contracting muscles can induce reactive hyperemia upon relaxation, resulting in increased shear stress on the vascular endothelium. This shear stress is known to enhance intracellular calcium concentrations via potassium channel activation and stimulate eNOS, thereby promoting NO production [32,33]. NO plays a key role in vasodilation and can reduce peripheral vascular resistance, ultimately contributing to BP reduction. Compared to localized isometric exercises involving only the upper or lower limbs, the plank exercise—by engaging large muscle groups throughout the body—may impose shear stress across a broader vascular territory, potentially eliciting a more pronounced vasodilatory response. This mechanism may, in part, underlie the significant reductions in 24-hour BP observed in this study. However, the precise physiological pathways remain to be fully elucidated, particularly in young adults with prehypertension, and warrant further investigation.

Although 24-hour systolic and diastolic BPV showed a downward trend following the plank session, these changes did not reach statistical significance. However, a significant reduction was observed in nighttime systolic BPV, suggesting a potential benefit of IPE in improving BP stability during sleep. Nighttime BP is considered a stronger and more independent predictor of cardiovascular events than daytime BP [34]. Moreover, increased nighttime BPV has been associated with impaired nocturnal dipping and disrupted autonomic regulation during sleep [35].

The present study employed ARV as the primary index of BPV. ARV has been shown to have stronger associations with cardiovascular risk and HTN-related outcomes compared to traditional SD measures [36,37]. Systolic ARV, in particular, is recognized as an independent predictor of cardiovascular events and target organ damage [20,21].

The BPV response observed in this study can also be contextualized within findings from other acute exercise modalities. Previous work has shown that acute aerobic exercise may induce short-term reductions in BPV, particularly with moderate to vigorous intensities [38]. Similarly, isometric handgrip training has yielded mixed results in both BP and BPV outcomes, with some studies reporting limited or non-significant effects [39,40]. Compared to these modalities, the isometric plank may offer a more robust hemodynamic effect, potentially due to the larger muscle mass involvement. Importantly, the entire intervention required less than 12 minutes to complete, underscoring its practicality and time efficiency for preventive strategies targeting young adults with prehypertension. Thus, the significant reduction in nighttime systolic BPV, along with the overall trend toward lower BPV following the plank session, highlights the potential of IPE as an early intervention strategy for young adults with prehypertension.

Despite the significant reductions in 24-hour ambulatory SBP and DBP following the isometric plank session, no meaningful changes were observed in AASI indices, including AASI (standard), AASI (BPVR), and BPVR. These findings are consistent with previous literature suggesting that AASI, while associated with long-term cardiovascular outcomes and arterial stiffness, may not be sensitive to short-term hemodynamic changes, as it is considered a surrogate index rather than a direct physiological measure such as pulse wave velocity (PWV) [41,42].

In addition, a study by Liu et al. [43] found that AASI was not significantly associated with pressor responses to sympathoexcitatory stressors following isometric handgrip exercise in young adults suggesting that AASI reflects relatively stable structural and functional arterial properties rather than acute autonomic reactivity. These findings highlight the limited sensitivity of surrogate indices to acute hemodynamic shifts. Therefore, the null AASI results may not indicate evidence against acute vascular effects. Accordingly, future studies should incorporate standard noninvasive assessments such as carotid–femoral PWV or flow-mediated dilation, and longer-term interventions may be necessary to clarify the responsiveness of these indices.

Several limitations should be acknowledged. First, although the cross-over design justified the inclusion of 12 participants, the small sample size limited the ability to examine subgroup effects and may restrict generalizability of the findings. Second, the study only evaluated acute responses within a 24-hour period, which precludes conclusions regarding the persistence of effects or vascular adaptation. Third, multiple exploratory comparisons were performed without multiplicity adjustment and such results should be regarded as hypothesis-generating and interpreted with caution. Fourth, the use of narrower fixed-clock intervals for ABPM in this study, adapted to young adults’ sleep-wake patterns, may restrict the generalizability of our findings.

CONCLUSION

The findings of this study demonstrate that even an acute IPE can elicit favorable hemodynamic effects including reductions in 24-hour ambulatory BP and nighttime BPV (ARV) in young adults with prehypertension. These results underscore the practicality and clinical potential of full body isometric exercise as a time-efficient and non-pharmacological intervention for early BP management. While no significant changes were observed in surrogate markers of arterial stiffness such as AASI, it may reflect their limited sensitivity to acute interventions. Therefore, future studies applying longer-duration exercise protocols are warranted to further elucidate the vascular adaptations underlying the BP lowering effects.

Abbreviations

ABPM

ambulatory blood pressure monitoring

ARV

average real variability

ANOVA

analysis of variance

AASI

ambulatory arterial stiffness index

BMI

body mass index

BP

blood pressure

BPV

blood pressure variability

BPVR

blood pressure variability ratio

CVD

cardiovascular disease

DARV

diastolic average real variability

DBP

diastolic blood pressure

eNOS

endothelial nitric oxide synthase

HR

heart rate

HTN

hypertension

IPE

isometric plank exercise

MAP

mean arterial pressure

NO

nitric oxide

PWV

pulse wave velocity

SARV

systolic average real variability

SBP

systolic blood pressure

SD

standard deviation

SUPPLEMENTARY MATERIAL

Supplementary Fig. 1

Systolic and diastolic blood pressure responses according to session order (plank-first and control-first) in the randomized cross-over trial to assess potential order and carryover effects.