Importance of Blood Volume and Its Interaction With Cardiovascular Adaptations

NCT05191979 | Unknown

• 1 other identifier: H-21011041
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 2

Brief Summary

The present project aims to investigate the interaction between training-induced blood volume expansion (plasma- and red blood cell volume responses), central as well as peripheral cardio-vascular adaptations. We will investigate cardiovascular responses through one year of training in recreationally active men and women as well as endurance athletes undertaking shorter training-periods/interventions with environmental heat-stress. The overall purpose with the project is to investigate the physiological effects of prolonged aerobic exercise on central cardiovascular parameters and peripheral effects in the muscle tissue in untrained individuals. Further, we want to compare these effects to exposure to environmental stress (heat) on performance well trained individuals. The present study consist of three parts using the same methodology in different populations to elucidate the above mentioned mechanisms. The first part is a larger training intervention in untrained/recreationally active men and women aiming at evaluating the initial cardiovascular adaptations to an exercise training regimen. In addition there are two parts aimed to elucidate the mechanisms leading to further improvements in cardiovascular and blood volume adaptations from exercise training in a different environmental condition and artificially elevated PV in already highly adapted endurance athletes.

Conditions

Exercise

Keywords

Blood volume; Cardiac function; Vascular function; Physiological Effects of Long-term exercise training; Mitochondrial function

Outcome Measures

Primary Outcomes (4)

• Maximal systemic oxygen uptake

  Training-induced changes in maximal systemic oxygen uptake (ml/min) is evaluated with an incremental maximal cycle protocol on a cycle ergometer

  20 minutes

• Resting and cycling stroke volume and function measured with echocardiography

  LV stroke volume (ml) and LV basal and apical twist (Deg) will be used to measure training-induced changes in LV function during exercise

  90 minutes

• Change in vascular conductance of the brachial artery

  Assessment of changes in arm vascular conductance (ml/min/mm/Hg/kg arm mass) to flow mediated dilation, infusion of Acetylcholine and sodium nitroprusside, assessed by ultrasound Doppler.

  2 hours

• Blood volume

  Training-induced changes in total blood volume (mL) is measured using the Carbon-monoxide rebreathing method.

  20 minutes

Secondary Outcomes (4)

• Mitochondrial biogenesis

  60 minutes

• Fat mass

  20 minutes

• Fat free mass

  20 minutes

• Cardiac dimentions

  90 minutes

Study Arms (2)

Blood volume interactions with cardiovascular adaptations

ACTIVE COMPARATOR

Individual differences in the time course and relationship between cardiovascular (central and peripheral) adaptations to long-term aerobic training and the concomitant blood volume changes.

Other: Exercise regiment (aerobic exercise on bike)

Sex differences

ACTIVE COMPARATOR

Evaluate differences between genders and hormonal factors influencing individual differences (high vs. low responders) - hypothesizing that female have a blunted cardiovascular response to long-term aerobic training.

Other: Exercise regiment (aerobic exercise on bike)

Interventions

Exercise regiment (aerobic exercise on bike) OTHER

Subjects participating in the current study will be trained progressively and intensively for 12 months primarily on bike indoors and outdoors

Blood volume interactions with cardiovascular adaptations; Sex differences

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• absence of metabolic, chronic diseases, uncontrolled arrhythmia, 2. or 3. degree AV-block or sick sinus syndrome
• no history of smoking or alcohol consumption (≥ 14 items / week)
• decent acoustic window for echocardiography.

You may not qualify if:

• chronic disease or taking medication
• history of \>2 years of exercise training
• failure to meet exercise raining criteria

Sponsors & Collaborators

• University of Copenhagen: lead
• University of Southern Denmark: collaborator

Study Sites (2)

Department of Nutrition, Exercise and Sports

Copenhagen, 2100, Denmark

Location

University of Copenhagen

Copenhagen, 2200, Denmark

Location

MeSH Terms

Conditions

Motor Activity

Condition Hierarchy (Ancestors)

Behavior

Study Officials

• Nikolai B. Nordsborg, Prof.

  University of Copenhagen - Department of Nutrition, Exercise and Sports

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Non-blinded, non-randomized intervention design

Study Record Dates

• First Submitted: December 10, 2021
• First Posted: January 14, 2022
• Study Start: January 6, 2022
• Primary Completion: November 1, 2024
• Study Completion: November 1, 2025
• Last Updated: November 29, 2023

Record last verified: 2023-11

Locations

DK (2)