Why You Don’t Need to Reschedule Your Workouts Around Your Period

In recent years, the idea of “cycle-syncing” (changing your food, activity or training based on your menstrual cycle) has flooded social media, fitness blogs, and wellness apps. The promise? That rising and falling hormones will give you the “best days” for strength, cardio, muscle building or recovery. But a growing body of scientific research — including a 2025 study from McMaster University — challenges that hype.

What the latest McMaster study found

Researchers at McMaster tracked healthy, naturally-cycling women over several months with careful cycle verification (blood tests, urinary ovulation kits, etc.) and had them do heavy resistance training during two key cycle phases: the high-estrogen “follicular” phase and the high-progesterone “luteal” phase. 

They measured muscle protein synthesis (MPS) and muscle protein breakdown (MPB) — the biological processes that underlie muscle growth — and found no significant differences between phases. Simply put: the body’s capacity to build or maintain muscle doesn’t change based on where you are in your cycle. ResearchGate+2SciTechDaily+2

Bottom line (as summed up by lead researchers): there is no “hormonal advantage” tied to cycle phase that meaningfully enhances strength or hypertrophy. 

You can find the full study here: https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2023.1054542/full

What this means for most women

• You don’t have to shift your training week to week depending on your period due to concern about your bodies ability to handle activity or gain muscle.
• If you lift weights, run, practice yoga, or do any form of exercise — you can do it consistently across your cycle and expect similar physiological benefits.
• Trying to precisely “sync” workouts to your cycle adds complexity — but the science doesn’t back the payoff.

What does matter — and when cycle-based tweaks may still make sense

That said, nothing says you should ignore how you feel. Hormonal changes might influence energy levels, mood, bloating, or cramping. Some days the thought of a heavy squat feels better than others. Listening to your body (sleep quality, hydration, stress, nutrition, etc) will always beat rigid cycle-phase rules.

For example, if on period week you feel fatigued or crampy, a lighter workout or rest day may be warranted. Not because of the concern regarding your hormones and their impact on your bodies ability to handle certain workouts, but because your body is giving you feedback and it is ok to listen to those messages and symptoms.

Also, the researchers note the evidence is still limited, especially outside of strength/resistance training contexts (e.g., endurance sports, elite athlete performance, recovery, etc.). McMaster Experts+2ScienceDaily+2

What this means for my clients that I work with as a nutrition/movement professional

As a professional who helps people balance nutrition, hormones, fitness and real life (hello, perimenopause + gut issues), this clears the way for a simpler, more realistic approach:

• Focus on consistency: regular strength, cardio, mobility training as tolerated
• Prioritize fundamentals: good protein intake, nutrient-dense eating (as tolerated), hydration, sleep, recovery
• Honour subjective experience: let clients adjust based on how they feel — not on some premise of a “best phase” during their cycle.
• Avoid overcomplication: skip the cycle-syncing apps or rigid “follicular = heavy lift / luteal = yoga only” rules — unless someone prefers them for personal reasons.

My Take:

Cycle-syncing might sound sexy and personalized, but the science from McMaster basically says “meh.” Unless you have symptoms that make movement hard, there’s no reason to overhaul your training plan every month. Consistency, intelligent programming, and listening to your body will get you farther than trying to hack hormones that (at least when it comes to muscle growth) don’t offer a magic advantage. Most people struggle with consistency enough as it is, we don’t need to complicate it further. That doesn’t mean that we shouldn’t adjust plans accordingly for the female body- it is meant to empower us and inform us that we can indeed continue to work hard regardless of what ‘time of the month’ it is.

So yeah, if you feel like lifting weights today, go for it. If you feel like yoga or Pilates tomorrow, that’s cool too. Your cycle doesn’t own your strength.

Interested in discussing a personalized plan for your health? Reach out to book a 1:1 consult here https://wellbalancedrd.com/virtual-services/