Cycle-Based Training in Sport

Cycle-based training has gained significant traction in recent years. The idea is appealing: align training with the hormonal fluctuations of the menstrual cycle to optimize performance, recovery, and adaptation. However, when we examine the scientific literature closely, the picture becomes far more nuanced. Hormonal changes are real—but their impact on performance is often overstated.

The menstrual cycle is primarily characterized by fluctuations in estrogen (estradiol), progesterone, and luteinizing hormone (LH).

Estrogen is often described as performance-enhancing. Mechanistically, this is not unfounded. Research suggests that estrogen may promote lipid oxidation, improve insulin sensitivity, and exert muscle-protective effects through influences on protein turnover and mitochondrial function. It may also affect neuromuscular function and connective tissue properties, which has led to speculation about its role in performance and injury risk.

Progesterone, which rises in the luteal phase, appears to have partly opposing effects. It increases basal body temperature, alters ventilatory responses, and may negatively influence glucose regulation under certain conditions. These physiological changes are often used to explain why some athletes report reduced readiness or increased fatigue later in the cycle.

Luteinizing hormone plays a key role in triggering ovulation and is primarily used in research to accurately identify cycle phases rather than directly influencing performance outcomes.

From this physiological framework, it seems logical to periodize training according to hormonal peaks and troughs. However, this is where theory and empirical evidence begin to diverge.

(Schlie et al., 2025)

A common narrative is that certain phases of the cycle are inherently “better” for performance, while others should be avoided for intense training. Current evidence does not support such clear distinctions.

Across studies, the effects of menstrual cycle phases on performance are generally small, inconsistent, and highly variable between individuals. Even when hormone levels are precisely measured, there is substantial overlap in physiological responses between phases.

Systematic reviews reinforce this inconsistency: some studies report phase-related differences, others find none, and when differences do appear, their direction and magnitude vary widely. This makes it difficult to derive generalized, phase-based training recommendations.

A key issue is interindividual variability. Hormone concentrations, receptor sensitivity, and downstream physiological responses differ markedly between women. As a result, two athletes in the same cycle phase may experience entirely different levels of performance and readiness.

In the context of strength training, the evidence is relatively consistent. Most studies show that maximal and explosive strength are not meaningfully affected by menstrual cycle phase.

Although some data suggest slight advantages in specific phases (e.g., late follicular phase), these effects are small and not consistently replicated. From a practical standpoint, this challenges the idea that strength training must be tightly aligned with the menstrual cycle.

In reality, factors such as training load, progressive overload, recovery, and nutrition are far more influential than hormonal fluctuations.

The situation is similar in endurance sports. Some studies report reduced performance (e.g., VO₂max) in the early follicular phase, while others show no differences at all. Overall, there is no consistent pattern linking endurance performance to specific cycle phases.

This suggests that menstrual cycle phase alone is not a reliable predictor of endurance capacity. Again, other variables—training status, energy availability, sleep, and environmental conditions—play a more dominant role.

(McNulty et al., 2020)

One area that has received less attention, but may hold some relevance, is neuromuscular coordination. Some evidence indicates that coordination and motor control may be improved around ovulation.

This could theoretically benefit activities requiring precision, timing, and rapid motor responses. However, as with other outcomes, the evidence is not robust or consistent enough to inform structured training strategies.

While hormonal effects on objective performance are often modest, cycle-related symptoms appear to have a much more direct and practical impact.

Research highlights that symptoms such as pain, fatigue, sleep disturbances, gastrointestinal discomfort, and fluid retention can significantly affect training capacity and day-to-day performance. These symptoms are particularly common in the premenstrual phase and during menstruation.

A systematic review confirms that menstrual cycle-related symptoms are widespread among female athletes and can meaningfully impair perceived performance and training consistency.

Unlike hormonal phase classifications, symptoms are immediately relevant to the athlete’s experience. They influence not only physical output but also motivation, concentration, and perceived effort.

(Taim et al., 2023)

Rather than relying on rigid, phase-based training models, our approach at Enduco is grounded in practicality and individualization. Current evidence clearly shows that the menstrual cycle provides a physiological context, but not a reliable framework for generalized training decisions.

This is why we focus on daily monitoring instead of fixed cycle-based assumptions. Through our daily check-in, we track key variables such as recovery, sleep quality, stress, and muscle soreness. These metrics offer a far more accurate reflection of an athlete’s readiness than cycle phase alone.

The key is enabling athletes to understand and monitor their day-to-day physical state.

The result is a data-driven, individualized approach—where training is guided not by the calendar, but by the athlete’s actual condition.

McNulty, K. L., Elliott-Sale, K. J., Dolan, E., Swinton, P. A., Ansdell, P., Goodall, S., ... & Hicks, K. M. (2020). The effects of menstrual cycle phase on exercise performance in eumenorrheic women: a systematic review and meta-analysis. Sports medicine, 50(10), 1813-1827.

Natalucci, V., Spinello, G., Moro, T., Pavei, G., Boccia, G., La Torre, A., & Bonato, M. (2026). Menstrual Cycle and Hormonal Contraceptives in Female Athletes: Should Symptoms and Nutrition Matter More Than Cycle Phase? A Narrative Review. Nutrients, 18(7), 1144.

Schlie, J., Krassowski, V., & Schmidt, A. (2025). Effects of menstrual cycle phases on athletic performance and related physiological outcomes: a systematic review of studies using high methodological standards. Journal of Applied Physiology.

Taim, B. C., Ó Catháin, C., Renard, M., Elliott-Sale, K. J., Madigan, S., & Ní Chéilleachair, N. (2023). The prevalence of menstrual cycle disorders and menstrual cycle-related symptoms in female athletes: a systematic literature review. Sports Medicine, 53(10), 1963-1984.