Neuromuscular performance changes throughout the menstrual cycle in physically active females

Area of Science:

• Sports Medicine
• Exercise Physiology
• Reproductive Endocrinology

Background:

• Menstrual cycle phases are associated with hormonal fluctuations that may impact neuromuscular function.
• Understanding these changes is crucial for optimizing athletic performance and injury prevention strategies in female athletes.

Purpose of the Study:

• To investigate the changes in neuromuscular performance across different phases of the menstrual cycle in young, active females.
• To determine if oral contraceptive use influences these menstrual cycle-related performance variations.

Main Methods:

• Fifty physically active college-aged females (25 on oral contraceptives) were assessed during the early follicular (Fp), ovulatory (Op), and mid-luteal (Lp) phases.
• Measurements included isokinetic peak torque (IPT) at the knee (60°, 180°, 300°/sec) and handgrip strength.
• Hormonal levels (estradiol, progesterone) confirmed cycle phases; serum relaxin was screened.

Main Results:

• Grip strength was significantly lower in the Fp compared to Op and Lp phases (p<0.001).
• Isokinetic peak torque at the knee was also reduced during the Fp across all tested velocities (60°/sec, 180°/sec, 300°/sec) compared to Op and Lp phases (p<0.001).
• No significant interaction between oral contraceptive use and menstrual cycle phase was observed for any outcome.

Conclusions:

• Muscular performance, including grip strength and knee extension torque, is diminished during the early follicular phase.
• The observed performance decrements are not significantly influenced by oral contraceptive use.
• These findings suggest that physically active females may face a heightened risk of injury during the early follicular phase due to reduced muscular strength.