title: Does menstrual cycle phase affect lung diffusion capacity during exercise?
abstract: Resting lung diffusing capacity (DLCO) decreases during the early and late-follicular phases of the menstrual cycle presumably due to capillary blood volume (VC) changes; however, it is not known if these differences exist during exercise. We hypothesized that DLCO would increase during the mid-luteal phase of the menstrual cycle due to increases in VC. Eight normally menstruating females (21.4±0.7 yrs) were studied. Subjects completed a discontinuous treadmill V˙O2max test during the early-follicular (EF), late-follicular (LF), and mid-luteal (ML) phases of the menstrual cycle. Metabolic measurements were made from a breath-by-breath automated cart, and DLCO via the single-breath exhalation technique during exercise. During exercise, DLCO was lesser during EF compared to ML at 90% and 100%V˙O2max (p<0.05) (90%: 37.8±3.7 EF vs 41.6±4.0 ML, 100%: 37.7±3.7 EF vs 42.6±4.3 ML mL/mmHg/min). VC was significantly greater during the ML phase when compared to the EF at 80%, 90%, and 100%V˙O2max. These results demonstrate DLCO and VC are influenced by the menstrual cycle during heavy exercise.
authors.affiliation: Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA. Electronic address: smith424@ksu.edu.
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Smith
authors.affiliation: Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Brown
authors.affiliation: Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.
authors.forename: Jill D
authors.initials: JD
authors.lastname: Murphy
authors.affiliation: Department of Kinesiology, Kansas State University, 1A Natatorium, Manhattan, KS 66506, USA.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Harms
mesh_terms: D001810:Blood Volume; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology*; D011653:Pulmonary Diffusing Capacity / Q000502:physiology*; D055815:Young Adult
keywords: Exercise; Lung diffusion capacity; Menstrual cycle; Pulmonary blood volume