Exercise Induced Plasma Volume Expansion Lowers Cardiovascular Strain

Cardiac Output Clinical Trial

Official title:

Exercise Induced Plasma Volume Expansion Lowers Cardiovascular Strain and Improves Cycling Time-trial Performance in Acute Normobaric Hypoxia

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05800808
• Other study ID #: Plasma Volume and Hypoxia
• Status: Completed
• Phase: N/A
• Start date: January 15, 2019
• Est. completion date: December 8, 2022

Study information

• Verified date: April 2023
• Source: California Baptist University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The goal of this observational study was to better understand the impact of increased plasma volume on later exercise in hypoxia. Investigators examined young, healthy, males who regularly participated in aerobic exercise.

Investigators first measured participant's response to exercise in hypoxia (simulated ~7,500 feet above sea level). The investigators then had participants either 1) undergo 1 bout of high intensity interval exercise or 2) undergo 1 bout of moderate, continuous exercise.

48 hours after the exercise, participants were again examined in hypoxia.

Description:

A crossover design was utilized to assess the effects of exercise-induced plasma volume expansion on cycling performance in hypoxia. All participants completed a high intensity (HI) bout and control (CON) intervention in a counterbalanced order. The HI bout consisted of 8x4min cycling bouts at 85% of VO2peak with 4 min rest between intervals. CON consisted of cycling at 50% VO2peak. Two 15 km, self-paced cycling time trials (TT) were performed before and after each training intervention. The first TT occurred 5 days before the training intervention (HI or CON) and the second TT occurred 48 hours post intervention. Interventions were separated by 14 days to ensure sufficient washout of any training effect as data have suggested retention of expanded plasma volume may last for 7-14 days. During washout, participants were instructed to continue their normal exercise routine.

The investigators hypothesized that a single HI session would increase plasma volume and attenuate cardiovascular strain during exercise in hypoxia, as evidenced by reductions in HR and elevations in SV and Q. Furthermore, the investigators hypothesized that these changes would contribute to a reduced time-to-completion in a 15 km, self-paced cycling TT.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 8
• Est. completion date: December 8, 2022
• Est. primary completion date: December 15, 2019
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years to 38 Years

Eligibility

Inclusion Criteria:

• Males age 18-38

• Exercise at least 3 times/week for at least 30 minutes/day for the past 3 months.

Exclusion Criteria:

• Frequent hot bath or sauna users

• Resided at altitude greater than 2,500 meters for >14 days.

• Cardiovascular or metabolic disease

Related Conditions & MeSH terms

• Cardiac Output
• Stroke Volume

Intervention

Procedure:
• High Intensity Intervals
8x4 min cycling bouts at 85% of VO2peak
• Moderate Exercise
81 minutes of cycling at 50% VO2peak

Locations

Country	Name	City	State
United States	California Baptist University	Riverside	California

Sponsors (3)

Lead Sponsor	Collaborator
California Baptist University	High Point University, United States Army Research Institute of Environmental Medicine

Country where clinical trial is conducted

United States, 

References & Publications (15)

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Beidleman BA, Staab JE, Muza SR, Sawka MN. Quantitative model of hematologic and plasma volume responses after ascent and acclimation to moderate to high altitudes. Am J Physiol Regul Integr Comp Physiol. 2017 Feb 1;312(2):R265-R272. doi: 10.1152/ajpregu.00225.2016. Epub 2016 Dec 30. — View Citation

Berger NJ, Campbell IT, Wilkerson DP, Jones AM. Influence of acute plasma volume expansion on VO2 kinetics, VO2 peak, and performance during high-intensity cycle exercise. J Appl Physiol (1985). 2006 Sep;101(3):707-14. doi: 10.1152/japplphysiol.00154.2006. Epub 2006 May 11. — View Citation

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Coyle EF, Hopper MK, Coggan AR. Maximal oxygen uptake relative to plasma volume expansion. Int J Sports Med. 1990 Apr;11(2):116-9. doi: 10.1055/s-2007-1024774. — View Citation

Fortney SM, Wenger CB, Bove JR, Nadel ER. Effect of blood volume on forearm venous and cardiac stroke volume during exercise. J Appl Physiol Respir Environ Exerc Physiol. 1983 Sep;55(3):884-90. doi: 10.1152/jappl.1983.55.3.884. — View Citation

Fulco CS, Muza SR, Beidleman BA, Demes R, Staab JE, Jones JE, Cymerman A. Effect of repeated normobaric hypoxia exposures during sleep on acute mountain sickness, exercise performance, and sleep during exposure to terrestrial altitude. Am J Physiol Regul Integr Comp Physiol. 2011 Feb;300(2):R428-36. doi: 10.1152/ajpregu.00633.2010. Epub 2010 Dec 1. — View Citation

Fulco CS, Rock PB, Cymerman A. Maximal and submaximal exercise performance at altitude. Aviat Space Environ Med. 1998 Aug;69(8):793-801. — View Citation

Gillen CM, Lee R, Mack GW, Tomaselli CM, Nishiyasu T, Nadel ER. Plasma volume expansion in humans after a single intense exercise protocol. J Appl Physiol (1985). 1991 Nov;71(5):1914-20. doi: 10.1152/jappl.1991.71.5.1914. — View Citation

Gillen CM, Nishiyasu T, Langhans G, Weseman C, Mack GW, Nadel ER. Cardiovascular and renal function during exercise-induced blood volume expansion in men. J Appl Physiol (1985). 1994 Jun;76(6):2602-10. doi: 10.1152/jappl.1994.76.6.2602. — View Citation

Greenleaf JE, Looft-Wilson R, Wisherd JL, Jackson CG, Fung PP, Ertl AC, Barnes PR, Jensen CD, Whittam JH. Hypervolemia in men from fluid ingestion at rest and during exercise. Aviat Space Environ Med. 1998 Apr;69(4):374-86. — View Citation

* Note: There are 15 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Hemoglobin Concentration	measured through spectroscopy	through study completion, an average of 4 weeks
Primary	Hematocrit Concentration	measured through hematocrit reader	through study completion, an average of 4 weeks
Secondary	Time Trial Time	Time to complete 15 km	through study completion, an average of 4 weeks
Secondary	Cardiac Output	measured via impedance cardiography	through study completion, an average of 4 weeks