The menstrual cycle may influence readiness, symptoms, thermoregulation and recovery, so training design should be flexible and individualized. However, it does not justify automatically assigning the same training intensity to every athlete during each phase.
In IB SEHS A.3.1, training design must account for sex differences, reproductive status and hormonal changes across an arbitrary natural 28-day cycle. Fluctuations in estrogen and progesterone may alter physiological responses, but their effects vary substantially between individuals and cycles.
| Cycle phase | Possible considerations for training design |
|---|---|
| Menstrual phase | Estrogen and progesterone are low. Cramps, heavy bleeding or fatigue may reduce readiness in some athletes, so load or exercise selection can be adjusted when symptoms affect performance. |
| Follicular phase | Estrogen generally rises while progesterone remains low. Some athletes may feel more able to tolerate demanding strength, power or high-intensity sessions, but progression should still depend on monitored performance. |
| Ovulation | Estrogen peaks around ovulation in a typical cycle. Coaches should not assume that this creates a universal performance peak. |
| Luteal phase | Progesterone rises and resting body temperature may increase. Heat management, hydration and recovery may require greater attention, especially when symptoms such as fatigue occur. |
Effective periodization therefore combines planned microcycles with athlete-specific monitoring. Coaches can record cycle phase, symptoms, sleep, perceived exertion, performance and recovery, then adjust training frequency, intensity or duration when consistent patterns appear. The principles of progressive overload, specificity and recovery still apply throughout the cycle.
A common misconception is that all athletes should follow rigid “cycle syncing.” Cycle length, hormonal responses, symptoms and contraceptive use differ, so phase-based changes should not replace individual data.
For an IB response, identify hormonal or symptom-related effects, explain how they could change load or recovery, and emphasize individual variation. Examiners reward application to safe, effective programme design rather than unsupported claims that one phase is always best for performance.