“Cycle syncing” has become a hot trend in the fitness and wellness space. Influencers claim that women should adjust their workouts according to the phases of their menstrual cycle—lifting heavy only during certain days, pulling back during others, and even skipping intensity altogether when hormones fluctuate.
It sounds empowering at first glance. But when we look at the science, the truth is far less glamorous: there is no solid evidence to suggest women need to systematically scale their training intensity based on cycle syncing.
What the science says
Research has repeatedly shown that performance variations across the menstrual cycle are inconsistent and highly individual:
- A 2020 meta-analysis in Sports Medicine reviewed 78 studies and found that while some small differences exist, overall strength and endurance performance are not systematically impaired during any specific menstrual phase. The authors concluded that prescribing training adjustments based on cycle syncing is not supported by evidence (McNulty et al., 2020).
- A 2021 review in the Scandinavian Journal of Medicine & Science in Sports similarly emphasized that although hormones fluctuate, the performance impact is highly individual, with some women experiencing dips, others improvements, and many showing no measurable changes at all (Blagrove et al., 2021).
- Even studies that do find differences often highlight that these variations are smaller than normal day-to-day performance fluctuations from sleep, stress, or nutrition (Elliott-Sale et al., 2020).
Why this matters
The danger with cycle syncing is that it can be disempowering. If you believe you should avoid hard training just because you’re in a certain phase of your cycle, you may be holding yourself back from sessions where you’re actually primed to perform at your best—or even hit a new personal record.
At CrossFit Kreis 9, we see women push through plateaus, set personal bests, and build consistency without limiting themselves to external charts or influencer-driven rules. True progress comes from training the body consistently, not from syncing it to a calendar.
The bigger picture
Most women who train don’t have the luxury of “wasting” sessions. Progress in the gym depends on consistency: showing up, lifting regularly, and gradually increasing intensity. If you’re only training two to four times a week, skipping intensity because of cycle syncing is far more detrimental than pushing through and building the habit of training no matter what.
What actually works
Instead of following a calendar based on hormone fluctuations, here’s what empowers women in training:
- Listen to your body: If you feel strong, go heavy. If you feel tired, adjust accordingly—but let that be based on you, not a prescriptive cycle syncing template.
- Prioritize consistency: Regular training, week in and week out, will yield far greater results than syncing intensity based on pseudo-science.
- Focus on progressive overload: Muscles and bones respond to training stress. Consistency and progression matter more than syncing to dates on a calendar.
- Acknowledge individuality: Every woman’s cycle is different. What matters is self-awareness, not influencer charts.
Final word
Your menstrual cycle is not a barrier to strength, power, or progress. At CrossFit Kreis 9, we believe that empowerment comes from building consistency, developing strength over time, and learning to trust your own body—not from following a color-coded cycle syncing chart.
That doesn’t mean you should ignore how you feel. Some women may notice subtle changes across their cycle, and adjusting intensity on a given day can make sense if you feel low in energy, stressed, or short on sleep. But these are decisions best made in the moment, based on your body, not dictated by a generic calendar someone else has created.
The reality is that training adaptations happen when you put in consistent work—lifting, moving, and challenging yourself week after week. Cycle syncing, as promoted on social media, risks telling women that they should hold back just when they might be ready to push forward. That’s not empowerment—that’s limitation.
So here’s our perspective:
- Show up.
- Train hard when you can.
- Adjust when you truly need to.
- Keep building strength and fitness as the foundation for long-term health.
Because the real key to results isn’t syncing workouts with your cycle. It’s showing up for yourself—day after day, week after week, year after year. And at CrossFit Kreis 9, we’ll always stand behind that message.
References
- McNulty KL, Elliott-Sale KJ, Dolan E, et al. (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.
- Blagrove RC, Bruinvels G, Read P. (2021). Effects of the menstrual cycle on exercise performance in female athletes. Scand J Med Sci Sports, 31(1), 8–26.
- Elliott-Sale KJ, Minahan CL, de Jonge X, et al. (2020). Methodological considerations for studies in women: an update. Frontiers in Physiology, 11, 1–13.
