Study Results
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Basic Information
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COMPLETED
NA
40 participants
INTERVENTIONAL
2023-01-02
2023-07-28
Brief Summary
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One key mechanism involved in blood pressure control is the baroreflex, which helps stabilize blood pressure by adjusting heart rate and blood vessel function. The sensitivity of the baroreflex (known as baroreflex sensitivity, or BRS) can vary between males and females. For instance, females may exhibit slower adjustments in heart rate in response to blood pressure changes, but they also tend to have better blood pressure regulation during moderate exercise.
The main purpose of this study is to explore whether these sex-specific differences extend to more intense exercise. Investigators will compare the responses of young, active males and females to cycling at two exercise intensities: moderate (50% of Heart Rate Reserve, HRR) and vigorous (80% HRR). As a secondary purpose, investigators we will assess the inter-day repeatability of HRV and BRS parameters measured at rest and during moderate and vigorous intensity exercise utilizing sequence and spectral indices in apparently healthy young adult males and females.
We hypothesize that:
1. Females will show higher HRV and BRS at rest compared to males, indicating better heart rate control.
2. During exercise, females will have greater cardiovagal (heart-related) activation than males, regardless of exercise intensity.
3. When exercise sessions are matched for blood pressure, there will be no significant sex differences in HRV and BRS responses.
4. Sequential methods techniques can be used to assess cardiovagal BRS and HRV changes between days during exercise in young adults, regardless of their sex. In addition, the inclusion of vigorous intensity may improve the repeatability of the outcome measure due to sympathetic outflow predominance.
Detailed Description
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This study was constructed as a crossover trial. Participants attended 4 separate intervention sessions. On the first visit, participants had their body composition evaluated by a clinical bioimpedance device using 8 electrodes positioned on each hand and foot. Each participant also performed a ramp incremental cycle ergometer test to exhaustion on a recumbent stationary cycle ergometer (Excite Recline Med, TechnoGym, Italy). On the second and third visit, participants quietly rested for 15 min in the supine position to evaluate heart rate variability (HRV) using a 5-ECG lead module (Nova, Finapres Measurement Systems, Amsterdam, The Netherlands), carotid (Arietta V60 ultrasound; Aloka/Hitachi Medical Systems) and aortic (Complior Analyse software (ALAM Medical, Paris, France) arterial stiffness. Participants then performed a 6 minutes bout of moderate intensity continuous exercise (MICE) at 50% heart rate reserve \[HRR= 0.5\*(HRmax- HRrest) + HRrest\] followed by a 6 minutes vigorous intensity continuous exercise (VICE) bout at 80% HRR on a recumbent stationary bike, while having their HRV, beat-by-beat blood pressure and carotid arterial stiffness evaluated at HR steady state at each intensity. Visits 2 and 3 provided the data for the repeatability objective and hypothesis. On the fourth visit, the participants performed an acute bout of MICE and VICE, but this time at the corresponding average blood pressure at each intensity from visits 2 and 3. As men show higher blood pressure values during exercise, in the fourth visit we matched their intensity of exercise with the average blood pressure attained by women during steady state at each intensity.
Blood pressure and HR were monitored beat-by-beat and carotid arterial stiffness was measured at BP steady-state.
All visits were conducted in the morning with each participant performing sessions at the same time of the day to minimize any potential diurnal variation.
Conditions
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Study Design
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NON_RANDOMIZED
CROSSOVER
OTHER
SINGLE
Study Groups
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Heart Rate Reserve (HRR)-Based Exercise Intensity Prescription
The exercise intensity is based solely on HRR.
Moderate Intensity Continuous Exercise
Participants perform a continuous cycling exercise session on a reclined ergometer at moderate intensity (50% HRR)
Vigorous Intensity Continuous Exercise
Participants perform a continuous cycling exercise session on a reclined ergometer, at a vigorous intensity (80% HRR).
Blood Pressure-Matched Exercise Intensity Prescription
Instead of relying on HRR, exercise intensity is tailored to replicate the average systolic blood pressure achieved in the initial HRR-based session.
Moderate Intensity Continuous Exercise Matched for Blood Pressure
Participants perform a cycling session where exercise intensity is adjusted to match the systolic blood pressure levels attained during the first visit at moderate intensity (50% HRR).
Vigorous Intensity Continuous Exercise Matched for Blood Pressure
Participants perform a different cycling session where exercise intensity is adjusted to match the systolic blood pressure levels attained during the first visit at vigorous intensity (80% HRR).
Interventions
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Moderate Intensity Continuous Exercise
Participants perform a continuous cycling exercise session on a reclined ergometer at moderate intensity (50% HRR)
Vigorous Intensity Continuous Exercise
Participants perform a continuous cycling exercise session on a reclined ergometer, at a vigorous intensity (80% HRR).
Moderate Intensity Continuous Exercise Matched for Blood Pressure
Participants perform a cycling session where exercise intensity is adjusted to match the systolic blood pressure levels attained during the first visit at moderate intensity (50% HRR).
Vigorous Intensity Continuous Exercise Matched for Blood Pressure
Participants perform a different cycling session where exercise intensity is adjusted to match the systolic blood pressure levels attained during the first visit at vigorous intensity (80% HRR).
Eligibility Criteria
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Inclusion Criteria
* Physical active as assessed by the International Physical Activity Questionnaire (IPAQ).
* Low risk to increase physical Activity as assessed by the Physical Activity Readiness Questionnaire (PAR-Q+).
Exclusion Criteria
* Diagnosed with cardiac, metabolic or renal diseases
* Taking cardioactive medication
* Resting hypertension (systolic blood pressure \>140 mmHg, diastolic blood pressure \> 90 mmHg).
18 Years
44 Years
ALL
Yes
Sponsors
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Faculdade de Motricidade Humana
OTHER
Egas Moniz - Cooperativa de Ensino Superior, CRL
OTHER
Responsible Party
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Locations
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Ginásio Clube Português
Lisbon, , Portugal
Countries
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References
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Bassareo PP, Crisafulli A. Gender Differences in Hemodynamic Regulation and Cardiovascular Adaptations to Dynamic Exercise. Curr Cardiol Rev. 2020;16(1):65-72. doi: 10.2174/1573403X15666190321141856.
Seo MW, Park TY, Jung H. Sex Differences in Heart Rate Variability and Vascular Function Following High-Intensity Interval Training in Young Adults. J Hum Kinet. 2023 Oct 11;90:89-100. doi: 10.5114/jhk/170964. eCollection 2024 Jan.
Schumann A, Gupta Y, Gerstorf D, Demuth I, Bar KJ. Sex differences in the age-related decrease of spontaneous baroreflex function in healthy individuals. Am J Physiol Heart Circ Physiol. 2024 Jan 1;326(1):H158-H165. doi: 10.1152/ajpheart.00648.2023. Epub 2023 Nov 10.
Wheatley CM, Snyder EM, Johnson BD, Olson TP. Sex differences in cardiovascular function during submaximal exercise in humans. Springerplus. 2014 Aug 20;3:445. doi: 10.1186/2193-1801-3-445. eCollection 2014.
Fu Q, Ogoh S. Sex differences in baroreflex function in health and disease. J Physiol Sci. 2019 Nov;69(6):851-859. doi: 10.1007/s12576-019-00727-z. Epub 2019 Nov 12.
Other Identifiers
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PACE MAKERS
Identifier Type: -
Identifier Source: org_study_id