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Maximal exercise as a countermeasure to orthostatic intolerance after spaceflight.
Med Sci Sports Exerc 2001; 33(1):75-80MS

Abstract

Previous investigators have suggested that maximal exercise performed 24 h before the end of bed rest, a spaceflight analog, restores prebed rest plasma volume, baroreflex responses, and orthostatic tolerance.

PURPOSE

In this case report, we examined the effect of a similar exercise protocol 24 h before a Shuttle landing on the orthostatic responses of four crewmembers (EX) after spaceflights of 8-14 d. Four additional crewmembers (CON) served as controls and did not perform exercise during the final day of the flight.

METHODS

Each crewmember performed a 10-min stand test approximately 10 d before launch (L-10) and within 1-2 h of landing (R+0). Cardiac stroke volume was measured (Doppler ultrasound) supine and during each min of standing for three EX and three CON subjects.

RESULTS

Preflight, all crewmembers completed the stand test and each group had similar heart rate and blood pressure responses. Postflight, all subjects also completed the 10-min stand test. Each group had similarly elevated supine and standing heart rates, elevated diastolic and mean arterial blood pressures, and reduced pulse pressures compared to L-10. However, postflight cardiac output, mean +/- SEM, (EX: 4.5+/-0.6 L x min(-1); CON: 3.1+/-0.3 L x min(-1)) and stroke volume (EX: 43+/-7 mL x beat; CON: 30+/-6 mL x beat) were higher after 10 min standing in the EX subjects compared to CON subjects.

CONCLUSIONS

For these four crewmembers, maximal exercise performed 24 h before landing may have helped maintain stroke volume but did not maintain heart rate and blood pressure responses during standing compared to preflight.

Authors+Show Affiliations

Wyle Laboratories, Life Sciences Systems and Services Division, and NASA-Johnson Space Center, Houston, TX 77058, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

11194115

Citation

Moore, A D., et al. "Maximal Exercise as a Countermeasure to Orthostatic Intolerance After Spaceflight." Medicine and Science in Sports and Exercise, vol. 33, no. 1, 2001, pp. 75-80.
Moore AD, Lee SM, Charles JB, et al. Maximal exercise as a countermeasure to orthostatic intolerance after spaceflight. Med Sci Sports Exerc. 2001;33(1):75-80.
Moore, A. D., Lee, S. M., Charles, J. B., Greenisen, M. C., & Schneider, S. M. (2001). Maximal exercise as a countermeasure to orthostatic intolerance after spaceflight. Medicine and Science in Sports and Exercise, 33(1), pp. 75-80.
Moore AD, et al. Maximal Exercise as a Countermeasure to Orthostatic Intolerance After Spaceflight. Med Sci Sports Exerc. 2001;33(1):75-80. PubMed PMID: 11194115.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Maximal exercise as a countermeasure to orthostatic intolerance after spaceflight. AU - Moore,A D,Jr AU - Lee,S M, AU - Charles,J B, AU - Greenisen,M C, AU - Schneider,S M, PY - 2001/2/24/pubmed PY - 2001/4/6/medline PY - 2001/2/24/entrez KW - NASA Center JSC KW - NASA Discipline Cardiopulmonary SP - 75 EP - 80 JF - Medicine and science in sports and exercise JO - Med Sci Sports Exerc VL - 33 IS - 1 N2 - UNLABELLED: Previous investigators have suggested that maximal exercise performed 24 h before the end of bed rest, a spaceflight analog, restores prebed rest plasma volume, baroreflex responses, and orthostatic tolerance. PURPOSE: In this case report, we examined the effect of a similar exercise protocol 24 h before a Shuttle landing on the orthostatic responses of four crewmembers (EX) after spaceflights of 8-14 d. Four additional crewmembers (CON) served as controls and did not perform exercise during the final day of the flight. METHODS: Each crewmember performed a 10-min stand test approximately 10 d before launch (L-10) and within 1-2 h of landing (R+0). Cardiac stroke volume was measured (Doppler ultrasound) supine and during each min of standing for three EX and three CON subjects. RESULTS: Preflight, all crewmembers completed the stand test and each group had similar heart rate and blood pressure responses. Postflight, all subjects also completed the 10-min stand test. Each group had similarly elevated supine and standing heart rates, elevated diastolic and mean arterial blood pressures, and reduced pulse pressures compared to L-10. However, postflight cardiac output, mean +/- SEM, (EX: 4.5+/-0.6 L x min(-1); CON: 3.1+/-0.3 L x min(-1)) and stroke volume (EX: 43+/-7 mL x beat; CON: 30+/-6 mL x beat) were higher after 10 min standing in the EX subjects compared to CON subjects. CONCLUSIONS: For these four crewmembers, maximal exercise performed 24 h before landing may have helped maintain stroke volume but did not maintain heart rate and blood pressure responses during standing compared to preflight. SN - 0195-9131 UR - https://www.unboundmedicine.com/medline/citation/11194115/Maximal_exercise_as_a_countermeasure_to_orthostatic_intolerance_after_spaceflight_ L2 - http://dx.doi.org/10.1097/00005768-200101000-00013 DB - PRIME DP - Unbound Medicine ER -