Sex Effects on Blood Pressure Regulation to Acute Isometric Handgrip Exercise, Following 4 Weeks of Isometric Handgrip Training
Phase: NA
Conditions: Blood Pressure
Sponsor: University of Massachusetts, Boston

Last revised 10-19-2023, PI: Tracy Baynard, PhD         Student investigator: João L. Marôco 
 
Sex Effects on Blood Pressure With Handgrip Training                                       
Research protocol 
This study will be designed as a randomized, controlled, cross-over, repeated measures 
experiment. Fifty young healthy adult participants (25 males and 25 females) will visit the 
laboratory three times to perform a fatiguing bout of isometric handgrip exercise before and after 
both 4 weeks of isometric handgrip training and a no-exercise training condition. Participants will 
be randomly allocated to the isometric handgrip and the non-exercise training conditions using 
an online program (http://www.randomizer.org/). Participants that start with isometric handgrip 
training will return to the laboratory after a 4-wk washout, as this duration has been shown to 
decondition cardiovascular outcomes following training (1–3). To eliminate diurnal variation, each 
participant will visit the laboratory at the same time of day. Main outcomes in each visit will be 
measured at rest, during the fatiguing bout of isometric handgrip exercise, and 5,10, 30, and 60-
min post-exercise (see figure and Table 1). These measurement timings are aimed to characterize 
BP, and the cardiac autonomic and vascular function biphasic responses (4–6). Visits 2 and 3 will 
take place within 7 days of the last training session. 
  
 
 
Figure 1: Experimental design, a randomized, controlled, cross-over, repeated measurements 
study. Abbreviations: CON; control, BRS baroreflex sensitivity, RMSSD, root mean square of 

Last revised 10-19-2023, PI: Tracy Baynard, PhD         Student investigator: João L. Marôco 
 
successive differences; HF, high-frequency power band; FMD; brachial artery flow-mediated 
dilation, cfPWV; central pulse wave velocity. 
 
Study intervention  
Baseline visit – fatiguing bout of Isometric handgrip exercise  
 
All participants will rest for 15-min, and then the MVC will be determined based on three 
attempts, each separated by 30-s, with participants in a supine position. The highest MVC will be 
used to define the exercise workload (30% MVC). Then, participants will perform a fatiguing bout 
of unilateral isometric handgrip exercise in the supine position using a digital handgrip transducer 
intertwined with a data acquisition system (Powerlab 16/35; ADInstruments, BellaVista, NSW, 
Australia). Participants will use their dominant hand and will hold the isometric contraction until 
task failure. The failure criteria will be defined as the inability to sustain the contraction force within 
5% of the target MCV percentage (i.e., 30%).  We chose to set the intensity at 30% MVC as this 
is the standard target intensity of isometric handgrip exercise protocols (7–9) and no differential 
BP responses have been reported when different intensities (i.e., 20 vs 30 and 45% MVC) are 
Table 1 Procedures to be conducted in each visit to the laboratory  
Procedures 
Time (min) 
Rest  
15 
Measurements 
 
1) BP, arterial stiffness, cardiac autonomic function 
5 
2) Brachial endothelial function (FMD) 
15 
Fatiguing isometric handgrip exercise 
~ 3-5 
Last isometric contraction  
 
Measurements  
 
1) BP, brachial blood flow 
 
2) Cardiac autonomic function (BRS, RMSSD, HF) 
 
Post 5 min 
 
Measurements 
 
1) BP, arterial stiffness (cfPWV), cardiac autonomic function 
(BRS, RMSSD, HF) 
5 
Post 10 min 
 
Measurements 
 
1) Brachial endothelial function (FMD) 
15 
Post 30 min 
 
Measurements 
 
1)  BP, arterial stiffness (cfPWV), cardiac autonomic function 
(BRS, RMSSD, HF) 
5 
2) 
Brachial endothelial function (FMD) 
15 
Post 60 min 
 
Measurements 
 
1) BP, arterial stiffness (cfPWV), cardiac autonomic function 
5 
2) Brachial endothelial function (FMD) 
15 
 
Total 
~ 100 

Last revised 10-19-2023, PI: Tracy Baynard, PhD         Student investigator: João L. Marôco 
 
used (10–12). Based on previous research, we expect that participants will fatigue within 3 to 5 
min (i.e., time to task failure) (12). Participants will receive both visual and auditory feedback to 
maintain the target exercise intensity throughout the session. The same fatiguing bout protocol 
will be used before and after the training intervention.  
Isometric handgrip training intervention and control  
 
Participants will train three days per week at home for 1 month using a reliable and 
validated digital handgrip dynamometer (DynX, MD System, Inc., Westerville, OH, USA)) in a 
seated position.  The isometric handgrip training protocol will consist of four sets (2 for each hand) 
of two-min sustained contractions starting at 30% MVC interspersed by 1-min resting periods (a 
total of 12-min). All training sessions will be remotely supervised via Zoom or phone call by a 
research team member to ensure compliance with the exercise prescription. Before each training 
session, MVCs will be re-assessed over three repetitions, each separated by 30-s, to ensure an 
accurate exercise prescription (13). The highest value will be used to determine the target 
intensity of the session. In the control/washout conditions, participants will be instructed to 
maintain their normal daily routines. 
Post-intervention visits – isometric handgrip exercise acute bout 
All participants will return to laboratory to complete the same acute bout of isometric 
handgrip exercise detailed in the baseline visit after the isometric handgrip exercise training and 
respective control. 
Study endpoints (clinical trials): 
NA 
Study main outcomes 
The main outcomes of this study are brachial BP (i.e., SBP and DBP), cardiac autonomic 
function (i.e., RMSSD, HF, and cardiac baroreflex sensitivity), and vascular function (i.e., flow-
mediated dilation (FMD), and central pulse wave velocity (cfPWV). 
Study Population 
Eligibility criteria 
Inclusion criteria 
Eligible participants for this study are 1) persons with normal BP as defined by the 
American Heart Association (<130/90 mmHg) and ages between 18-40 years; 2) those with BMI 
< 30 kg/m2; 3) persons with no cardiovascular risk factors and no clinically diagnosed 
cardiovascular disease; 4) persons recreationally active (≤ 2 days of structured physical activity); 
and 4) able to speak and comprehend English.  
Exclusion criteria  
Prospective participants will be excluded if they report 1) diagnosed cardiovascular (e.g., 
coronary artery disease, heart failure), musculoskeletal (i.e., osteoporosis and sarcopenia), and 
kidney disease; 2) taking antihypertensive or other vasoactive medications and cardioactive 
medication; 3) obesity (i.e., BMI > 30 kg/m2); 4) hypertension (i.e., ≥ 130/90 mmHg; 5) diabetes 
mellitus (i.e., fasting HbA1 > 6.5%); 6) depression and anxiety disorders; 6) long COVID; 7) being 
a smoker; 8) pregnancy or menstrual irregularities among females.  

Last revised 10-19-2023, PI: Tracy Baynard, PhD         Student investigator: João L. Marôco 
 
Excluded vulnerable populations 
 
Pregnant females will be excluded due to pregnancy-induced changes in hormonal 
concentrations and cardiovascular regulatory mechanisms.  
Study Duration 
We foresee that this study will be completed in one year. The estimated duration of 
individual participation in this study is 2 months and each visit to the laboratory will take 
approximately 2h. 
Number of Participants 
We aim to sample 50 young healthy adults, 25 males, and 25 females. 
Study Setting 
All study measurements will be conducted in Integrative Physiology Human Laboratory 
(IHPL) at the University of Massachusetts Boston located at 100 Morrissey Blvd in the Quinn 
Administration Building. The isometric handgrip training intervention will be conducted at the 
home of each participant enrolled in this study. 
Prior approvals: 
NA  
 
External IRB/ethics review: 
 NA. 
Local permissions/local context:  
NA 
Recruitment methods 
Recruitment will be conducted at the University of Massachusetts Boston and in the 
greater metropolitan Boston area. We will ask to place recruitment flyers at the University of 
Massachusetts Boston and to use the email services. Word of mouth will also be used as a 
recruitment strategy.  All communication, including electronic and social media, will only be used 
to spread information about the study. Persons interested in this study will initiate contact via our 
study phone call line or the Integrative Human Physiology Laboratory email for further study 
details and subsequent screening for eligibility.  We will only contact potential subjects as a follow-
up to those who initiate contact with study personnel first. Prospective participants will be 
screened over the phone using the Physical Activity Readiness Questionnaire for Everyone (PAR-
Q Plus), the International Physical Activity Questionnaire (IPAQ), and a health history 
questionnaire along with age, sex, and menstrual cycle regularity. To minimize coercion and 
undue influence on participants verbal and non-verbal/behavioral expressions will be used to 
assess possible objections or resistance to taking part in the study. At any time during the study, 
participants can withdraw without any negative consequences. 

Last revised 10-19-2023, PI: Tracy Baynard, PhD         Student investigator: João L. Marôco 
 
Procedures involved 
Study assessment procedures 
Cardiovascular function 
During the study visits, all non-invasive cardiovascular function measurements detailed 
below will be done in a quiet climate-controlled room (22-24º C) after a 15-min resting period, 
during, and after the fatiguing handgrip exercise with participants in a supine position. Participants 
will be tested in a fasted state (4h) and have refrained from exercise, caffeine/alcohol intake, and 
vitamins/supplements in the last 24h. Cardiovascular function testing in females will occur without 
controlling for the menstrual cycle (33,34), given that a growing body of literature supports little 
to no variation in BP, cardiac autonomic (i.e., BRS), and vascular function outcomes (i.e., brachial 
artery FMD and cfPWV) at rest and during acute exercise across the menstrual cycle or oral 
contraceptive pill cycle (25,27–32).  
 
Blood pressure  
 
Participants will be asked to wear a non-invasive inflating and deflating finger cuff during 
all study visits. This will allow beat-to-beat BP to be recorded using finger plethysmography 
(Finometer; Finapres Medical System, Amsterdam, The Netherlands) before, during, and after 
isometric handgrip exercise in the supine position. Beat-to-beat BP will be averaged offline over 
2 to 5-min using Lab Chart 8 (ADInstruments, BellaVista, NSW, Australia). Beat-to-beat dynamic 
fluctuations in BP induced by acute isometric handgrip exercise will be quantified through BP 
variability indices including spectral methods using the adapted HRV module of Lab Chart 8. This 
will give insight into sympathetic outflow to blood vessels (14,15). 
 Brachial BP of the right arm will also be measured three times at 1-minute intervals before 
and after isometric handgrip exercise using an automated blood pressure cuff (HEM-7311-ZSA; 
Omron Healthcare Co, Ltd, Kyoto, Japan) (16). Measurements will be accepted if they do not differ 
> 4 mmHg, and the average of the last two will be used for data analysis (16). Mean arterial 
pressure will be estimated as 2/3 DBP + 1/3 SBP.  
Central BP will be assessed via carotid artery tonometry (NIHem, Cardiovascular 
Engineering Inc., Norwood, MA). Brachial systolic and diastolic cuff BPs will be used to calibrate 
the peak and trough of the signal-averaged pressure waveforms. Carotid pressure waveforms will 
be calibrated with diastolic and integrated mean brachial cuff pressure. Central BP is then 
estimated from the calibrated carotid pressure. Central pulse pressure will be calculated as the 
difference between the peak and trough of the calibrated carotid pressure waveform. 
24-hour ambulatory BP will be monitored with the AMBPro devices (SonmoMedics, 
Randersacker, Germany), which uses pulse transit time technology.  The cuff will inflate every hour 
at night and every 30 min during the day, for measurement of standard brachial BP during the 
inflation/deflation cycle. BP between cuff inflation is determined continuously from pulse transit 
time measurements derived from concurrent electrocardiogram and photoplethysmography 
recordings. This device validated by the European Society of Hypertension can also be 
programmed to obtain pressures using conventional oscillometry during cuff inflation. Participants 
will be instrumented with four limb electrodes on their chest for the electrocardiogram recording.  
A cuff will be placed on their non-dominant arm that contains the photoplethysmography sensor. 
Data will be exported from the device for off-line analyses of the 24-hr BP and heart rate signal.  
The physical activity and movement sensors embedded within the device will allow for clear 
identification of daytime and nighttime pressures.   

Last revised 10-19-2023, PI: Tracy Baynard, PhD         Student investigator: João L. Marôco 
 
 
Cardiac autonomic function  
 
We will place electrodes directly on the skin of each participant to obtain the ECG trace 
required to estimate both heart-rate variability and baroreflex sensitivity outcomes. 
Heart rate variability and baroreflex sensitivity: R-R intervals will be sampled at 1000 Hz 
frequency to obtain digital R waves digital sequences using the single ECG lead module of 
PowerLab data acquisition system (ADInstruments, BellaVista, NSW, Australia). All data 
acquisition and offline analyses will be conducted following the standards of the Task Force of the 
European Society of Cardiology and the North American Society of Pacing and Electrophysiology 
(17). Offline heart rate variability (HRV) analyses will be performed over a 2-min time series for 
each time-point (i.e., baseline, during and 5, 30 and 60 min after exercise) using the HRV analysis 
module of Lab Chart 8 (ADInstruments, BellaVista, NSW, Australia) (18). Main time-domain indices 
of interest include the standard deviation of NN intervals (SDNN) – a measure of overall variability, 
and the root mean square of the sum of the squares of the differences between NN intervals 
(RMSSD) – a measure of cardiovagal modulation. In addition, non-linear time-domain parameters 
will be derived from the Poincaré plot, including the vertical deviation that reflects mainly 
cardiovagal modulation (SD1), the longitudinal deviation (SD2), and the non-linear ratio SD1/SD2 
an index of autonomic balance analogous to LF/HF ratio (19). The time-frequency domain analysis 
will be conducted using the Lomb-Scargle Periodogram, which permits accurate estimation of low 
(0.04 to 0.15 Hz) and high-power frequency (HF) power bands (0.15 to 0.40 Hz) in absolute and 
normalized power units during exercise conditions. Cardiac baroreflex sensitivity (BRS) will be 
estimated via the spontaneous sequence method over 2 min through the Lab Chart 8 baroreflex 
macro. Briefly, this method identifies ramps where increases in SBP (> 1 mmHg) are coupled with 
increases of the RR interval (> 4 ms) (linearly correlated) that occur over at least 3 beats (minimum 
sequence). The minimum acceptable correlation coefficient between SBP and RR interval ramps 
will be 0.80. Then, baroreflex sensitivity is estimated as the average of all regression slopes 
between the SBP and RR interval.  
 
Vascular function  
 
During the vascular function measurements, we will ask participants to lie quietly in the 
supine position. They will also experience a forearm occlusion to permit the assessment of 
endothelial function.   
Endothelial function: will be non-invasively assessed via brachial artery FMD, which represents 
nitric oxide-dependent vasodilation and closely correlates with the endothelial function of the 
coronary arteries (20,21). FMD will be assessed in the right brachial artery with an ultrasound 
(Arietta V750, Fujifilm, Tokyo, Japan) equipped with a 7.5-MHz linear array probe incorporating a 
5-MHz Doppler transducer, placed ~4 cm above the antecubital fossa, and held by a stereotactic 
clamp following standard guidelines (22,23). Reactive hyperemia will be induced by rapid cuff 
deflation following a forearm occlusion (Hokanson SC10, Bellevue, WA 98005, USA) maintained 
for 5-min at 250 mmHg. Changes in intraluminal brachial artery diameter will be tracked with 
automated edge-detection software (FMD studio, Quipu srl, Pisa, Italy) allowing precise 
measurement of the artery diameter (23). Doppler measurements of peak hyperemic blood 
velocity with an insonation angle of ≤ 60º will allow calculation of FMD main stimuli - shear rate as 
(4 × peak blood velocity / Dbaseline) (23).  All FMD analyses will be done offline using the FMD studio. 
FMD will be presented both as an absolute change (FMD (mm) =Dpeak – Dbaseline) and as a relative 
change (% FMD = (Dpeak -Dbas/Dbaseline) ×100) in diameter. If a non-linear ratio between Dpeak and Dbas 

Last revised 10-19-2023, PI: Tracy Baynard, PhD         Student investigator: João L. Marôco 
 
is observed ( coefficients < 1), %FMD will be allometrically scaled for Dbaseline (24,25). In addition, 
blood flow will be estimated as (Mean blood velocity) x (Brachial Cross-Sectional Area) x (60). 
Brachial artery blood flow will be measured in both exercising and non-exercising arms. All FMD 
scans will be conducted by the same researcher with inter-day measurements CV <15% (22,23). 
 
Arterial stiffness: cfPWV the non-invasive gold standard measurement of central arterial stiffness 
will be assessed using an applanation tonometry automatic device (NIHem, Cardiovascular 
Engineering Inc) with participants lying supine. Briefly, common carotid artery and femoral artery 
pressure waveforms will be recorded using a high-fidelity strain-gauge transducer placed 
separately on both arteries permitting pulse transit time estimation through the ECG R-wave to 
the foot of the applanation waves (intersecting tangent foot-to-foot method). PWV is then 
calculated by dividing carotid-femoral distance (subtraction method) by pulse transit time (26). 
Pulse waveforms velocity from carotid-brachial and radial artery tracts will also be measured and 
interpreted as regional indices of upper limb stiffness. All measurements will be conducted by 
reliable operators (i.e., CVs < 5%) on the right side of the body and ensuring that repeated 
measurements differ by less than < 0.5 m.s-1 (27). Brachial waveforms and BP will be used to 
calibrate central pressure waveforms.  
 
Local carotid stiffness and blood flow will also be measured from the common carotid 
artery using a high-resolution ultrasound (Arietta 750, Fujifilm, Tokyo, Japan) and high frequency 
(7.5 MHz) linear probe. Carotid artery diameter and blood velocity will be measured using the 
wave intensity mode with the probe placed on the skin over the carotid artery approximately 1-2 
cm to the proximal carotid bifurcation with a 60-degree insonation angle. Carotid stiffness indices 
such as  stiffness (eq.1) and PWV (eq.2) will be estimated according to the manufacturer’s 
formulas:  
(𝑒𝑞. 1) 𝛽= ln [
𝑆𝐵𝑃/𝐷𝐵𝑃
(𝐷𝑠𝑦𝑠𝑡−𝐷𝑑𝑖𝑎𝑠𝑡)/𝐷𝑑𝑖𝑎𝑠𝑡
]  
Where,  is beta stiffness; SBP, brachial systolic blood pressure, DBP, diastolic blood pressure; 
Dsyst, brachial artery diameter during systole; Ddiast, brachial artery diameter during diastole. 
 
(𝑒𝑞, 2) 𝑃𝑊𝑉= √((𝛽× 𝐷𝐵𝑃)/(2𝜌) 
 
Where, PWV is brachial artery pulse wave velocity; , beta stiffness, DBP, brachial diastolic blood 
pressure; and r, is blood density - assumed constant (1050 kg/m3). 
Body composition 
Participants will seat for 5-min inside the Bod Pod, (Body Composition System; Life 
Measurement, Incorporated, Concord, CA), a large egg-shaped chamber to have their body 
composition measured via air plethysmography. Participants will enter the Bod Pod only wearing 
minimal clothing (briefs for males and swimsuit for females), a swim cap and will be asked to 
breathe normally for 20-s and then into an internal breathing tube to measure thoracic gas volume. 

Last revised 10-19-2023, PI: Tracy Baynard, PhD         Student investigator: João L. Marôco 
 
This will permit the estimation of body density needed to calculate % of body fat via the Siri 
equation (28). The Bod Pod will be calibrated before each test following the manufacturer’s 
instructions with the chamber empty while using a cylinder of known volume (50 L).  
Pulsatile hemodynamics and wave separation analysis 
 
Pulsatile hemodynamics and wave separation analysis 
 
Aortic impedance will be measured following the method outlined by Mitchell et al (29,30). 
Aortic impedance describes pulsatile flow and pressure relations at the proximal aorta in early 
systole before the return of reflected waves. Firstly, 2D parasternal long-axis images of the left-
ventricular (LV) outflow tract will be acquired using a 2-4-Mhz ultrasound transducer (Arietta V750, 
Fujifilm, Tokyo, Japan). This will permit the determination of aortic diameter defined as the largest 
diameter in early systole close to the aortic leaflets. Then, a 2-MHz continuous echo Doppler 
flowmeter (pedof) probe (Arietta V750, Fujifilm, Tokyo, Japan) will be placed at the suprasternal 
notch to estimate aortic flow as the product of blood velocity and LV outflow tract area. Lastly, 
carotid pressure waveforms will be acquired via applanation tonometry (NIHem, Cardiovascular 
Engineering Inc). Both aortic flow and carotid pressure signals will be integrated into the NIHem 
software to estimate aortic impedance as the ratio of carotid pressure by aortic flow. In addition, 
waveforms will be separated into forward (Pf) and backward waves (Pb) with their ratio considered 
an index of general wave reflection, using the NIHem software as previously described (30). 
Follow up 
This study will not have a follow-up. 
Data Analysis Plan  
Data integrity 
All study procedures described in this protocol will be performed by trained personnel and 
all raw data will be checked within the same day of the visit by the research team who collected 
it. Biweekly examinations of the analyzed data will be performed by the PI to ensure high-quality 
analysis is being performed.  
Sample size 
Based upon an effect size of 0.160 and a drop-out rate of 15%, a priori power analysis (G-
Power Version 3.1.9.3) for mixed ANOVA suggested a total of 50 participants are required to 
detect SBP mean differences of at least 5 mmHg over time and groups (α= 0.05, 1−β=0.80). 
Despite this mean difference obtained from a study that characterized BP responses after acute 
isometric handgrip exercise (7), we also aim to examine the effects of training on acute blood 
pressure responses to isometric handgrip exercise. Thus, given these differences in study design, 
we additionally set the effect size considering the small, standardized effect sizes (≤ 0.20) for 
exercise training sciences (31). 
Statistical analysis 
Linear mixed models will be used to examine the effects of acute isometric handgrip 
exercise and training on BP, cardiac autonomic, and vascular function outcomes over time (i.e., 
aim 1, 2, and 3). These will be fitted with restricted maximum likelihood and applying 
Satterthwaite's method for approximating degrees of freedom for the F test using R lmerTest 
package (32). Fixed effects will be set as time, sex, training condition, and the random intercept 
as each participant. All models’ residuals will be checked for normality and homogeneity of 

Last revised 10-19-2023, PI: Tracy Baynard, PhD         Student investigator: João L. Marôco 
 
variances using both Shapiro-Wilk and Levene tests, respectively, and through QQ plot inspection 
using the R performance package (33). Natural logarithm (Ln) transformations will be applied to 
HRV outcomes, as these are generally not normally distributed, but both transformed and 
untransformed data will be presented. Linear mixed models will be run with and without possible 
outliers identified through box plots as observations lying outside the 1.5 interquartile range. 
Unbiased effect sizes - partial omega squares (ω2) will be estimated for each fixed effect and 
interactions terms and interpreted accordingly to the rough benchmarks set by Cohen (34) [small 
(ω2 < 0.05), medium (ω2 < 0.25), and large ω2 > 0.25) effects sizes]. Post-hoc comparisons will be 
performed using the Bonferroni correction, in the presence of significant fixed effects and 
interactions. MVC, %fat and free fat mass, and physical activity outcomes will be added to all linear 
mixed models as covariates, whereas resting HR and SRauc will be added to FMD and HRV main 
outcomes, respectively. In addition, the repeated measures correlation coefficient will be used to 
test associations between isometric handgrip exercise-induced BP changes before and after the 
training intervention and of BP with cardiac autonomic and vascular function outcomes (35). 
Multiple imputation procedures using full information maximum likelihood will only be used in case 
of a significant amount of missing data on outcomes (>15%) and if missing completely at random, 
as linear mixed modeling provides robust estimates for small to medium amounts of missingness 
(36). All statistical analyses will be conducted using R software, version 4.2.3 (37) with a significant 
level (α) of 0.05.  
 
 
Individual blood pressure responsiveness to isometric handgrip training  
We aim to conduct an exploratory analysis of the individual BP responsiveness to isometric 
handgrip training. Participants will be classified as showing relevant (responder) or negligible 
(non-responder) training-related hypotensive effects using the ROPE + HDI decision rule to reject 
or non-reject the null – a Bayesian method (38,39). Briefly, this method estimates the percentage 
of the highest density interval (HDI, like CI in frequentist statistics) within the range of values 
around the null – region of practical equivalence (ROPE). This estimated percentage corresponds 
to different levels of significance that will guide the training-related hypotension individual 
response classification with non-responders defined as > 99 %, likely responders < 5%, and 
responders < 1% of HDI within the ROPE (38,39).  
The HDI calculated as an 89% credible interval will be derived from each participant’s 
posterior normal distribution obtained from 1000 simulations based on the individual pre-to-post 
change in SBP and DBP (delta) and respective standard deviations calculated as TE/2, where TE 
is the technical error calculated as CV/2 *100) (38–40). Individual normal distributions will be 
derived using the R’s rnorm function. We will estimate the ROPE as 20% of the baseline SBP and 
DBP standard deviations in each group (sex) and this represents the smallest worthwhile 
difference (41–43). Both the HDI and the ROPE will be computed with R package bayestestR (44). 
Participants will then be classified according to the ROPE + HDI decision rule. This method of 
classifying responders mitigates some pitfalls of the traditional response threshold binary 
classification, such as not accounting for within-participant measurement error variability 
associated with blood pressure or the magnitude of group differences in mean response 
(40,41,45). 

Last revised 10-19-2023, PI: Tracy Baynard, PhD         Student investigator: João L. Marôco 
 
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