Date of Award

2025

Document Type

Dissertation

Department

Physical Education

First Advisor

Hunter S. Waldman

Second Advisor

Rebekah Carpenter

Third Advisor

Lauren Killen

Abstract

Hormonal fluctuations that occur throughout the menstrual cycle (MC) have been shown to affect substrate utilization and oxygen uptake when running. These MC induced changes could manifest as altered running economy (RE) when expressed as energy cost (Ec) and oxygen cost (O2c). Therefore, the current study aimed to determine if RE differs between MC phases, the early follicular phase (E-FP) and the mid-luteal phase (M-LP). Twelve eumenorrheic female recreational runners (ages 25 ± 4y; VO2peak 40.9±4.6 ml/kg/min) completed submaximal RE bouts (60%, 70%, 80% of VO2peak) during the E-FP and M-LP. During each bout, oxygen consumption (VO2), respiratory exchange ratio (RER), minute ventilation (VE), heart rate (HR), and rate of perceived exertion (RPE) were recorded. RE was calculated as O2c (ml/kg -1/km-1) and Ec (kcal/kg -1/km-1). There were no significant differences in O2c or Ec at any intensity (all p < 0.05). Additionally, RER, VO2, VE, and HR did not differ between trials (all p < 0.05). RPE was significantly higher during the E-FP (5 ± 1) compared to the M-LP (4 ± 1) when running at 60% VO2peak (p = 0.04) but did not differ at any other intensity (70% p = 0.28, 80% p = 0.71). In conclusion, RE in terms of O2c or Ec does not differ between MC phases in recreational female runners, although perceived effort is greater during the E-FP when running at moderate intensities.

Download

Share

COinS