Background: Concurrent training, defined as the combination of endurance and resistance exercises within a short time frame, has recently gained significant attention in women due to its relevance for performance, health, and body composition. However, the unique hormonal characteristics of women may influence physiological adaptive responses and potentially modulate the degree of interference between strength and endurance adaptations.
Methods: This paper presents a narrative review with a systematic approach, conducted in accordance with the PRISMA 2020 guidelines. A systematic search of PubMed, Scopus, Web of Science, and Google Scholar was performed from each database’s inception until January 2025. English-language studies were included if they investigated concurrent resistance and endurance training in women, including randomized controlled trials, interventional studies, and observational studies reporting outcomes related to strength, endurance, hormonal responses, or interference effects. Studies focusing exclusively on hydration, nutrient timing, or unrelated performance modifiers were excluded. A total of 55 studies met the inclusion criteria. Due to methodological heterogeneity, meta-analysis was not feasible; therefore, findings were synthesized narratively across three predefined domains. Certainty of evidence was assessed using the GRADE framework.
Results: Across the included studies (n = 55), evidence of moderate certainty suggests that estrogen may attenuate muscle damage and modulate interference effects on strength adaptations, particularly in the follicular phase. However, evidence regarding luteal-phase recovery and progesterone-mediated effects remains limited and of low certainty. Endurance-dominant sequencing appears to increase AMPK activation, potentially inhibiting mTOR signaling, although findings are inconsistent. Overall, hormonal fluctuations may partially explain sex-specific responses to concurrent training.
Conclusion: Due to sex-specific physiological and hormonal characteristics, women exhibit distinct responses to concurrent training. Targeted manipulation of training variables according to menstrual cycle phase and the reduction of conflicting molecular signaling can mitigate interference effects and enhance performance.
