Plasma Volume during Heat Stress and Exercise in Women,
Abstract
To determine whether PV was affected by the menstrual cycle, we studied five women during exercise and passive heating. The exercise bout (80% VO2 peak) on a modified cycle ergometer and the passive heat stress were done in a hot environment during the follicular and luteal phase. Esophageal temperature (T sub es) was measured continuously. VO2 was measured immediately after each blood sample, which was drawn after each 0.2C increase in T sub es. Initial PV was estimated at rest during the follicular phase. PV changes from rest were calculated at each T sub es from Hb and Hct. During passive heating, PV decreased by a mean volume of 156 (+ or - 80) ml to 2.83 (+ or - 0.09)lamba in the follicular phase. During the luteal phase, there was a larger volume reduction (300 + or - 100ml) during passive heating, and the final PV was lower (2.47 + or - 0.18 lamba) than in the follicular phase. During exercise, PV decreased 463 (+ or - 90) ml to 2.50 + or - 0.11 lamba in the follicular and 381(+ or - 70) ml to 2.50 (+ or - 0.23)lamba in the luteal phase. These data indicate that there is a menstrual cycle effect on PV during passive heating such that final PV is lower during the luteal phase. During severe exercise there is a greater PV loss during the follicular phase, yet the final PV is not different between phases. Keywords: Severe exercise, Follicular phase, Luteal phase.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1986
- Accession Number
- ADA174816
Entities
People
- Lou A. Stephenson
- Margaret A. Kolka
Organizations
- United States Army Research Institute of Environmental Medicine