Concentrating strength training in the follicular phase may help, but the evidence is too thin and low quality to recommend over a standard plan
Interpretation
A few small trials, such as Sung et al.'s within-subject study of 20 women, found larger strength and muscle gains with follicular-based training, and Kissow et al.'s review judged it possibly superior. Colenso-Semple et al.'s umbrella review judged the same studies low quality, noting unverified ovulation and changes within measurement error, and concluded it is premature to recommend phase-based training. Meanwhile, Bruinvels et al.'s survey of 6,812 exercising women found symptoms very common and linked to missed or changed training. Graded limited: a handful of small studies, reviews disagreeing on how to read them, and no data in endurance athletes.
Practical implication
Follow a standard progressive strength plan across the whole cycle, track cycle and symptoms, and adjust sessions for how you feel rather than for a predicted phase. None of the training studies included endurance athletes or women using hormonal contraception.
Sources
4 sources, independently verified.
Within-subject trial over three cycles: the leg trained mainly in the follicular phase (8 follicular, 2 luteal sessions) gained more isometric strength and muscle diameter than the leg trained mainly in the luteal phase (P < 0.05). Ovulation was not confirmed (per Colenso-Semple et al. 2023).
Critical review concluding that follicular phase-based resistance training is possibly superior to luteal phase-based training for strength and muscle mass, based on a small number of studies, and calling for further research.
Umbrella review of 5 reviews (rated low to moderate quality): scant, low-quality and inconsistent evidence of phase differences in strength, performance or hypertrophy; premature to conclude hormone fluctuations matter. Key training studies had problems (ovulation unverified; a 0.2 kg lean-mass change within DXA error). Recommends individualising training and tracking cycle and symptoms rather than phase-based programming.
Survey: mood changes/anxiety (90.6%), tiredness (86.2%), stomach cramps (84.2%) and breast pain (83.1%) were the most common symptoms; higher symptom frequency was associated with missing or changing training (OR 1.09 per index point), missing competition, absenteeism and pain medication use. Self-report; symptom index not yet validated.