Running Economy After a Low- and High-Intensity Training Session in Naturally Menstruating Endurance-Trained Female...

Area of Science:

• Exercise Physiology
• Sports Science
• Female Athlete Health

Background:

• Running economy is crucial for endurance performance and typically assessed during prolonged exercise.
• The influence of the menstrual cycle phase on running economy during training sessions is not well understood.
• Understanding these factors is vital for optimizing training strategies in female athletes.

Purpose of the Study:

• To evaluate the maintenance of running economy during 1-hour low-intensity training (LIT) and high-intensity training (HIT) sessions in female athletes.
• To determine if the menstrual cycle phase (early follicular, ovulatory, mid luteal) confounds the assessment of running economy.
• To differentiate the impact of LIT versus HIT on running economy.

Main Methods:

• Naturally menstruating, endurance-trained females (n=16 for LIT, n=17 for HIT) completed three LIT and/or three HIT sessions.
• Sessions were performed during distinct menstrual cycle phases: early follicular, ovulatory, and mid luteal.
• Running economy was measured as energy cost (kcal/kg/km) and oxygen cost (mL/kg/min) before and after each training session.

Main Results:

• Running economy, measured by energy cost, was maintained before and after both LIT and HIT sessions.
• Oxygen cost remained stable after LIT but showed a slight increase after HIT sessions.
• Menstrual cycle phase did not significantly affect the ability to maintain running economy.

Conclusions:

• Female athletes can maintain running economy during typical 1-hour LIT sessions.
• Running economy is largely maintained during HIT, although oxygen cost may slightly increase.
• Menstrual cycle phase does not appear to be a confounding factor in assessing running economy during these training durations.