The internet is loud when you’re a woman who dares to age.
It’s loud when you’re a woman who dares to lift heavy and build muscle.
It’s loud when you unapologetically educate midlife women about their own bodies.
And on my feed, you know who’s making (most of) the noise?
Well, let’s just say it ain’t me.
These are random, unqualified [insert expletive here] sitting behind their keyboards telling me what a woman “should” look like at 45. At 55. At whatever age they deem judgable. (I may or may not have gone off in my stories this week about this very topic.)
It’s wild, Betty.
You can dedicate your whole life to studying, training, building businesses, raising a family, and kicking ass in every domain… and you’re still reduced to your appearance. That’s the culture we’re in.
It’s the same culture that doesn’t study women’s health and instead treats us like small men… or tells us to suck it up when some troll on Instagram comments on our bodies.
So today, I want to talk about something that’s getting wildly oversimplified on the fitness internet: women’s physiology.
WHAT
The EBITS (Evidence-Based Internet Trolls… both men and a surprising number of women) keep shouting that the research shows “no significant difference in muscle-building capacity across the menstrual cycle.”
As if women are single-variable experiments. As if they have any clinical experience.
And technically? They’re not wrong. But they’re missing the entire body for the muscle fibers.Yes, women can build muscle in every phase.
Yes, progressive overload still works.
Yes, mechanical tension still drives adaptation.
No, you’re not wasting half your month.
But if we’re only measuring muscle, we’re ignoring everything else that makes us human.
WHY
Performance isn’t just muscle. It’s about a dozen other systems that shift in rhythm with your hormones.
Here’s what DOES change across your cycle, and why it matters, and how your performance may change across the menstrual cycle:
- Connective tissue: Estrogen fluctuates throughout the cycle and affects ligament laxity, tendon compliance, and joint stiffness. You’re still growing muscle, but the same lift can hit differently week to week, and that matters for injury risk.
- Heat tolerance: Progesterone raises your core temperature during the luteal phase, making cardio feel harder at the same output. Ever wonder why indoor spin classes have fans all over the place? To decrease your perceived exertion and help you avoid overheating. If you’re getting tired earlier in the second half of your cycle, this might be why.
- Fuel use: You’ll rely more on carbs at some points in your cycle, and more on fat at other points. This affects high-intensity repeat efforts, sprint tolerance, and fatigue when there is a fuel mismatch. Want bursts of energy and explosive power? You need carbs. High intensity? Call on your anaerobic system. If you’re not fueling well before training, you’re going to experience a lot of variation over your cycle.
- Insulin sensitivity: The late luteal phase brings more blood sugar swings and lower insulin sensitivity. You might feel shaky mid-workout, tired earlier, or get ridiculously hangry post-workout. That reflects your increased recovery demands. You might need to take an extra day (gasp!) or two (!!) to recover. (You might need a deload week too, but I feel like I’m already pushing it by suggesting a day off!)
- Coordination and balance: Your proprioception, timing, and motor unit firing efficiency change with hormone fluctuations – you’re not just clumsy. This might look like your lifts feeling “off” even if the strength is there, or your technique degrading earlier than expected. This is a good time to modify technical lifts because they require more cognitive effort to maintain form, aka protect from injury.
- Breathing efficiency: Progesterone increases your respiratory drive, making conditioning feel harder even with the same VO₂. You’ll notice this most in metabolic conditioning finishers, interval work, circuit training, and even high-rep leg training. We’re more efficient breathers in the luteal phase. (Check out my convo with Patrick McKeown for a fascinating deep dive on this.)
- Pain tolerance: Estrogen modulates your pain sensitivity and ligament and tendon behavior. Throughout the cycle, your path threshold will fluctuate, joint discomfort can feel more pronounced, and you might have puffy, inflamed days. This doesn’t necessarily mean injury, but the estrogen fluctuation does change tolerance and movement confidence.
- Sleep and recovery: Hormonal changes affect REM depth, sleep continuity, and overnight recovery signaling, which explains why two identical sessions can feel wildly different. Heart rate variability dips without an obvious cause (mine always tanks after I ovulate up until I bleed), and motivation drops even when discipline is high.
- Fluid balance: Hormones influence how your body handles sodium, water retention, and tissue pressure. This impacts joint stiffness, puffiness, heavy limb sensations, joint compression tolerance, and range of motion. Your tissues may be fine… they’re just holding more volume.
So yes, you can (and should) train hard all month, but what “hard” looks like also changes from the follicular to the luteal phase, and pretending nothing changes in your body is just bad science. Things change, so any trained clinician would tell you that adaptations should be made.
Elite performance has always respected system-level shifts… because men have them too. Women just have fluctuations that can be mapped into a calendar.
HOW
This is where I bring in the Big Ovary Energy.
I’m not interested in “hacking” my cycle or “overcoming” my hormones. I’m interested in working with them.
Here’s what that looks like in real life:
During my follicular phase, I go heavier. I can go all out and still recover faster, sleep better, and push intensity. Here is where I typically push for PRs
In the luteal phase, I pivot. Shorter rest periods, lighter weights but higher reps, more tempo work, more walks, more recovery tools, and more social media and email rants to you.
In the context of muscle building (which yes is important but it is not the ONLY thing), I am always aiming to approach muscle failure, understanding that the load and intensity with which I will reach it will change.
I stay consistent, but I stop expecting myself to feel the same every day.
I track my cycle and my energy. If my lifts feel off because my joints or tendons feel a bit tweaky, I adjust the volume or technique to prevent injury. I don’t label myself as lazy.
This is what women’s performance looks like when you respect your biology. Adaptive, intelligent, dynamic, and still powerful as hell.
NOW
If your workouts have felt “off,” I want to invite you to see it as feedback rather than a weakness.
Note when your energy, sleep, and strength fluctuate this month.
Give yourself permission to adapt rather than push.
Remember that building muscle isn’t the whole story. Building awareness is key.
I’m tired of people pretending that women’s bodies are hormoneless and unchanging.
Last week, I laid out 6 New Rules of Femininity, and I might add this to the list: train with enough intelligence to handle a dynamic system and still dominate.
Go out there and lift something heavy, no matter where you’re at in your cycle.
🌟 Love these recommendations? Find more resources to support your health in midlife in my Health Toolkit!
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