The change in motivation for functional sport performance tests across the menstrual cycle

Background To date, motivational changes across menstrual cycle phases in the context of functional performance testing remain insufficiently explored, with prior research often employing inconsistent definitions of cycle phases. This study aimed to examine changes in motivation for functional performance tests between menstruation, post-ovulatory phase and assumed mid-luteal phase in naturally menstruating individuals.

Methods Twenty-five women (age 28.44±4.35 years, weight 65.35±10.68 kg, menstrual cycle length 28.8±3.55 days) participated. Motivation was assessed using a single-item-question, the Intrinsic Motivation Inventory (IMI) and the Positive and Negative Affect Schedule (PANAS). Data were analysed using linear mixed models.

Results No statistically significant changes in motivation across menstrual cycle phases were found using the single-item question (F=0.20, p=.818), PANAS positive affect (F=0.55, p=.577), PANAS negative affect (F=0.33, p=.719) or interest/enjoyment subscale of IMI (F=1.56, p=.216). A statistically significant change in motivation across menstrual cycle phases was found in overall IMI score (F=3.77, p=.026), with post-hoc comparisons revealing a statistically significant difference between post-ovulatory phase and assumed mid-luteal phase (estimated difference=0.18, SE=0.07, p=.043).

Conclusion Although a statistically significant change was found in IMI scores, it may not be clinically meaningful. Visual inspection of data suggested high inter- and intra-individual variability across menstrual cycle phases and cycles. Monitoring both menstruation and motivation may provide deeper insights into performance variability at the individual level.