Influence of Menstrual Cycle Phase on Adaptations to Sprint Interval Training

Overview

Sprint interval training improves endurance performance and induces metabolic adaptations in muscle. Most research demonstrating these responses has been conducted in males, with limited studies evaluating changes to endurance performance and skeletal muscle oxidative capacity in females. Moreover, it is currently unknown if training in specific phases of the menstrual cycle influences adaptations to training. Thus, the purpose of the present study is to compare adaptations to 2 weeks of sprint interval training performed in the follicular vs. luteal phase of the menstrual cycle in healthy, eumenorrheic women. We will also determine how these responses differ from males.

The primary purpose of the present study is to determine if menstrual cycle phase influences adaptations to 2 weeks of sprint interval training. We will also determine if these responses differ from males. Female participants will be randomized to perform 6 sessions of sprint interval training over 2 weeks in either the Follicular Phase or Luteal Phase of their individual menstrual cycle. Blood and urine sampling will be used to confirm menstrual cycle phases. Training will involve 4-6 x 30-second Wingate sprints with 4 minutes of rest in between (\~14-28 min per session). Before and after the training intervention, investigators will measure participant's aerobic and anaerobic performance, cardiorespiratory fitness and skeletal muscle outcomes. Performance and fitness measures are performed on on a stationary bike, and muscle outcomes are measured by taking a small amount of muscle from the vastus lateralis (thigh) muscle. This study will advance knowledge on how the menstrual cycle and sex influences adaptations to training.