Most of the fueling advice floating around cycling was built on studies of male athletes, then handed to everyone else as if it were universal. That’s not a conspiracy – it’s just how the research funding worked for decades. But it does mean that if you’re a woman lining up in Kalkaska in November, some of the standard advice is going to fit you fine, some of it needs adjusting, and a few pieces of your nutrition picture never get mentioned at all.
This post is about that last group. Not because women’s nutrition is exotic or complicated, but because the things that most often hold female riders back – iron status, chronic underfueling, bone health, the shifts that come with perimenopause – are rarely part of the conversation until something breaks.
It’s August. Iceman is Saturday, November 7. That’s about three months, which is exactly the right amount of runway to fix the things on this list. Most of them can’t be fixed in race week.
Start Here: Put Your Cycle on the Calendar
If you’re still cycling, the single most useful thing you can do this month is figure out roughly where race day is going to land.
Count forward from your last period in cycle lengths. If you average 28 days, November 7 is about four and a half cycles from mid-July. You won’t nail it to the day – cycles drift, and training load and stress push them around – but you’ll know whether you’re likely to be in the first half or the second half of your cycle on race morning. That’s enough to plan around.
If you’re not tracking already, start now. A note in your phone is fine. What you want by October is a few months of your own data, not an app’s average of someone else’s.
Why it matters: not because one phase is “bad” for racing – women win national championships in every phase – but because knowing where you are lets you make small, specific adjustments instead of guessing at why you feel off.
What Actually Changes Across Your Cycle
Let me be honest about the state of the science here, because I think you deserve that more than you deserve a tidy answer.
The broad hormonal picture is well established. In the first half of your cycle – the follicular phase, from the start of your period through ovulation – estrogen rises and progesterone stays low. In the second half, the luteal phase, both estrogen and progesterone are elevated. Those hormones do measurably affect substrate use, core temperature, fluid balance, and protein turnover.
What is much less settled is how much any of that changes race-day performance. When researchers pooled the available studies, the average effect on performance turned out to be small and, importantly, highly individual. Some women feel a real difference. Some feel nothing. Both are normal.
So the useful framing isn’t “your hormones will sabotage you.” It’s “there are a handful of predictable physiological shifts, and if you happen to be someone who feels them, here’s what to do.”
The shifts worth knowing about
- Body temperature. Core temperature runs slightly higher in the luteal phase – roughly half a degree Fahrenheit. In a summer criterium, that’s a real thermoregulatory tax. At Iceman, in 30-degree woods, it’s a non-issue and arguably an advantage.
- Fuel use. Estrogen promotes fat oxidation and tends to spare muscle glycogen. Progesterone works somewhat against that. The practical translation is not “eat fewer carbs in one phase” – at Iceman intensities you are burning carbohydrate regardless. It’s that some women find they need slightly more total carbohydrate to feel normal in the luteal phase, especially on hard days.
- Protein turnover. Progesterone increases protein breakdown. If you’re going to be in your luteal phase during your heaviest training block or on race day, nudging protein up is a low-cost hedge.
- Fluid balance. Fluid shifts are common in the late luteal phase. That can show up as a scale change that has nothing to do with body composition, and as a slightly higher sodium need. Don’t panic-diet in response to a number on the scale that week.
- Perceived effort. The days right before your period are when most women report higher perceived exertion at the same power. Effort feels harder than the numbers say it should. If race day lands there, plan to race by feel less and by plan more – stick to your fueling schedule and your pacing targets rather than negotiating with how you feel at mile eight.
If race day lands in your luteal phase
Nothing dramatic changes. Add a bit more carbohydrate in the two or three days before the race than you otherwise would, keep sodium intake steady rather than restricting it, hit your protein, and trust the plan you practiced. The cold weather at Iceman genuinely works in your favor here.
Iron: The One Most Likely to Be Quietly Costing You
If you take one thing from this post, take this one.
Iron is central to oxygen transport, and endurance athletes lose it through more channels than the general population – sweat, gut losses, foot strike and impact, and for menstruating athletes, monthly blood loss on top of all of it. Low iron stores can drag down your aerobic capacity and leave you flat and heavy-legged long before you’d ever show up as clinically anemic on a standard blood panel.
This is the classic silent performance leak. You don’t feel a sudden drop. You just feel like your fitness stopped responding to training, and you assume you need to work harder – which makes it worse.
What to do
- Ask your doctor for a full iron panel, not just hemoglobin. You want ferritin, which reflects stored iron, along with hemoglobin and transferrin saturation. Ferritin is the number that flags a problem early. Many sports medicine practitioners start paying attention in endurance athletes well before the lab’s “low” cutoff, so ask for the actual number rather than just “normal or not.”
- Do it now, not in October. If your iron is low, correcting stores takes months, not weeks. August testing gives you time. Race-week testing gives you nothing but anxiety.
- Don’t supplement blind. Iron overload is a real problem, and supplementing without knowing your status can mask other issues. Test first.
- If you do supplement, get the details right. Absorption is better in the morning and worse in the hours right after a hard session, when your body’s iron-regulating response is elevated. Vitamin C helps absorption; coffee, tea, and calcium-rich foods taken at the same time work against it. Every-other-day dosing is often absorbed better and tolerated better than daily.
- Build the food side regardless. Red meat, shellfish, liver if you’ll eat it, plus beans, lentils, tofu, and fortified grains paired with a vitamin C source. Plant iron is absorbed less efficiently, so pairing matters more if you’re eating mostly plant-based.
Are You Actually Eating Enough?
This is the uncomfortable section, and it’s the one I’d most like you to sit with.
Low energy availability means you’re not taking in enough fuel to cover both your training and the basic business of keeping your body running. It doesn’t require an eating disorder. It happens constantly to conscientious, motivated athletes who simply increased training volume and never increased food to match – or who picked up a nutrition message somewhere that leaner equals faster and quietly ran a deficit for months.
The downstream effects hit bone density, hormonal function, immune function, mood, gut health, and – eventually and inevitably – performance. The performance drop usually arrives last, which is exactly what makes it so easy to miss.
Warning signs
- Your period has become irregular, lighter, or stopped altogether and you’re not pregnant or on a contraceptive that explains it
- You’re getting sick more than you used to, or minor illnesses linger
- You have a history of stress fractures or bone stress injuries
- You’re always cold, even by Northern Michigan standards
- Recovery between hard sessions is taking noticeably longer than it used to
- Training is going up and performance is flat or going backwards
- Sleep is poor, mood is low, or you feel unusually irritable and can’t point to a cause
- You think about food, restriction, or your weight more than feels comfortable
Losing your period is not a sign that training is going well. It is a physiological alarm, and it’s the one most often dismissed as normal in endurance sport. It isn’t.
If several of these sound familiar, please talk to a sports nutrition coach or a physician who works with athletes. This is fixable, and it’s much more fixable now than after a stress fracture in September takes your season.
Bones: More Relevant to Cyclists Than We Admit
Cycling is largely non-weight-bearing, which is wonderful for your joints and unhelpful for your skeleton. Mountain biking gives you more impact and loading than road riding does, but not enough to count as bone-building on its own. Add in the fact that bone loss accelerates around menopause, and this becomes a category worth actively managing rather than assuming.
- Calcium. Aim for roughly 1,000–1,300 mg per day, mostly from food. Dairy, fortified plant milks, canned fish with bones, tofu set with calcium, and leafy greens all count.
- Vitamin D. At this latitude, we make essentially none from sunlight between roughly October and March. Get your level tested and supplement based on the result rather than a guess.
- Load your skeleton. Two short strength sessions a week does more for your bone density than any supplement, and it will make you a more durable bike handler on rough sections of the course. This is the single best training investment most female cyclists aren’t making.
Perimenopause and Menopause
If you’re in your forties or fifties, some of what you’re experiencing on the bike may have nothing to do with your training plan.
As estrogen declines, several things shift at once: muscle becomes less responsive to the protein you eat, body composition tends to move even when your habits haven’t, recovery slows down, sleep quality often degrades, and thermoregulation gets less predictable. It’s a genuinely disorienting stretch, and a lot of women respond by cutting calories – which is precisely the wrong lever.
What actually helps
- More protein, better distributed. This is the phase to stop being casual about it. Aim for 30–40 g of protein at each main meal rather than back-loading it all at dinner. The higher per-meal dose is what overcomes the reduced sensitivity.
- Resistance training. Not optional anymore. It’s the primary defense of both muscle mass and bone density through this transition, and it directly protects your power on the bike.
- Creatine. The evidence for 3–5 g per day in menopausal women- for muscle, and possibly for cognition and bone – has gotten meaningfully stronger. It’s inexpensive and well tolerated. Worth a conversation with your physician.
- Don’t cut calories to chase the scale. Under-fueling accelerates every problem in this list. If you’re training for a 30-mile race, eat like it.
Protein: The Number to Actually Hit
Endurance athletes need considerably more protein than the general population guidelines suggest – in the range of 1.6 to 2.0 grams per kilogram of body weight per day. For a 140-pound rider, that’s roughly 100 to 130 grams daily. Emerging work suggests women may sit at the upper end of that range rather than the lower, particularly in the luteal phase and after menopause.
Distribution matters as much as the total. Three or four servings of 25 to 40 grams spread across the day beats a small breakfast and an enormous dinner, even if the totals match.
The practical test: add up what you actually ate yesterday. Most riders I work with are surprised, and the gap is almost always at breakfast.
Callouts
Masters women, 40 and up
The perimenopause section is your section, but so is the strength training line in the bone section. Two sessions a week, consistently, from now through October will change how you feel on the rough sections between Williamsburg and the finish. It is the highest-return thing on this entire page for you.
Junior girls racing the Slush Cup or Junior Iceman
You are training and still growing, which means your fuel needs per pound are higher than an adult’s, not lower. Eating enough is not a side note to your training – it is your training. Underfueling during your teenage years affects bone density you will carry for the rest of your life, and it ends more promising athletic careers than any crash ever will. Eat the second breakfast.
Men reading this
Don’t skip it. If you train with women, coach them, or are raising one, the iron and low-energy-availability sections are worth knowing well enough to recognize in someone else. Your post is next month.
Your August Action List
- Start tracking your cycle so you know roughly where November 7 lands.
- Book a blood draw and ask for a full iron panel including ferritin, plus vitamin D.
- Add up one honest day of protein and see where you land against 1.6–2.0 g/kg.
- Put two strength sessions a week on the calendar and treat them like rides.
- Read the low energy availability warning signs again, honestly. If more than two apply, make the call to a professional this month.
None of this is exotic. It’s the unglamorous infrastructure underneath a good race – the stuff that determines whether the fueling plan we build in October has anything solid to sit on top of.
Coming up in September: we flip to the men’s side. Testosterone, protein timing, masters-specific carbohydrate needs, and why the “just ride hard and eat whatever” approach works right up until the year it doesn’t. Fueling for Women: The Hormonal Nutrition Playbook for Iceman doesn’t.
Gina Render is a certified Performance Nutrition Coach that works with a variety of athletes and active individuals both locally and remotely to help them meet their goals. As a wife, mom of two teens avid mountain biker, and strength athlete, she understands the demands that come with balancing life and sport. From sport-specific fueling to general nutrition, she’s your partner and advocate to empower you to Adventure More. Contact her at gina@adventure-more.com.

