In recent years, fasting has gone from a fringe concept to a mainstream health trend. But when it comes to fasting for women, the conversation becomes much more complex—and more personal. Scroll through social media or check the comments on a fitness post about intermittent fasting, and you’ll quickly see just how passionate people are about this topic.
Some swear by it. Others say it made them feel worse.
Take me, for example: I wake up absolutely starving. My sister, on the other hand, can’t even think about food before noon. I feel drained if I don’t eat before working out. But my friend Jules? She can’t train properly if she eats beforehand.
With so many conflicting experiences, it’s easy to get lost in the noise. But here’s the truth: when it comes to fasting for women—especially active women—there’s a lot more to consider than just skipping meals.
What Is Fasting, Exactly?
At its core, fasting simply means going without food (and sometimes drink) for a certain period. Technically, we all fast overnight while sleeping. That natural break gives the body a chance to rest, repair, and burn through stored energy.
Where it gets more deliberate is with intermittent fasting (IF)—a structured approach that extends the fasting window beyond just sleep. One of the most popular versions is time-restricted eating (TRE), where meals are limited to a specific window (like 8 hours) and fasting occurs for the remaining 16.
For instance, someone might stop eating at 6 p.m. and not eat again until 10 a.m. the next day. This often aligns with periods of low activity and is intended to maximize the body’s ability to use fat for fuel.
Why Fasting Hits Different for Women
Despite the growing popularity of intermittent fasting, most scientific studies in this area have been conducted on men or animals. That’s a problem. Women’s bodies operate on entirely different hormonal rhythms, and those rhythms are deeply affected by calorie intake and stress—including stress from exercise and fasting.
Most existing research on fasting for women focuses on sedentary or overweight individuals. For active women, there’s a significant gap in the science. And yet, many fitness communities and influencers treat fasting like a one-size-fits-all solution.
But it’s not.
Women who train regularly—especially those in perimenopause—have unique nutritional needs. Undereating or fasting too long can lead to issues like decreased performance, poor recovery, and hormonal disruptions.
Is Fasting Good for Weight Loss?
Yes and no.
Fasting can help reduce calorie intake by limiting the time you eat—but studies show that when calorie intake is equal, fasting isn’t superior to other methods like mindful eating, portion control, or tracking macros.
In short, fasting is just one method of calorie restriction, and it doesn’t necessarily produce better results than others.
What Happens When You Fast and Exercise?
This is where things get tricky.
Both fasting and exercise reduce blood glucose levels. So when you combine them, your energy tank may be running on empty. This can make workouts feel harder, increase fatigue, reduce focus, and compromise your performance.
Some women also experience dizziness, nausea, or feel faint during fasted workouts. And without adequate protein and carbs in your system, your body may start breaking down muscle tissue for energy—something no active woman wants.
If you choose to train fasted, it’s essential to eat enough during your feeding window, prioritizing protein and carbohydrates to support muscle repair and prevent low energy availability.
Self-Awareness Is Your Best Tool
There’s no universal rule when it comes to nutrition, and fasting is no exception. Understanding your own body’s signals is key.
Some women feel energized and focused when they fast. Others feel sluggish, moody, or find their workouts suffer. Your response to fasting can depend on many factors—your activity level, hormones, age, stress, sleep, and more.
Jules Mitchell, author of Yoga Biomechanics: Stretching Redefined, once said something that stuck with me: “The older I get, the more grateful I am that I grew up doing sports. It taught me early on how to listen to my body.”
If you’re just starting to tune into your body’s needs—especially during perimenopause—don’t be surprised if it feels overwhelming at first. The key is to start small, pay attention, and adapt based on how you feel.
Are You Undereating Without Realizing It?
This is a major issue, especially among active women. Thanks to years of diet culture and outdated advice about “eating 1,200 calories a day,” many women are unknowingly under-fueling their bodies.
A 2016 study found that nearly half of recreational female exercisers were at risk for low energy availability, even without engaging in extreme dieting.
Undereating can:
- Stall muscle growth
- Disrupt hormonal function
- Decrease bone density
- Lead to fatigue and mood swings
Instead of restricting more, many women actually need to eat more—especially carbs and protein—to support their training and health.
A Nutritionist’s Perspective
Michaela Smith, a certified nutritional therapist, has worked with hundreds of women and shares this insight: “Most of my clients are already under-fueling, even those trying to lose weight. Fasting often just adds another layer of stress.”
She recommends:
- Eating a balanced breakfast within an hour of waking
- Having consistent meals and snacks throughout the day
- Aiming for a 12-hour overnight fast rather than extended fasts
- Prioritizing stable blood sugar and steady energy
The Role of Hormones and PCOS
For women with PCOS, intermittent fasting may help improve insulin sensitivity and manage symptoms like irregular cycles and acne. But these findings are mostly limited to overweight, premenopausal women.
In perimenopause, fasting can increase the risk of Relative Energy Deficiency in Sport (RED-S), which affects hormonal health, bone density, and recovery. The signs—fatigue, poor performance, irregular periods—can easily be mistaken for normal aging, making it harder to identify the root issue.
Carbohydrates, in particular, are critical for hormonal support during midlife.
Final Thoughts: Should Women Fast?
Fasting can be effective for some, but it’s not a magic solution—and it’s certainly not risk-free.
If you’re an active woman, prioritize fueling well over fasting hard. Your workouts, hormones, and energy all depend on it. And always consider your long-term health over short-term trends.
Before adopting any fasting protocol, especially as a woman who exercises regularly, it’s worth consulting a qualified dietitian or nutritionist who understands your unique needs.
Because in the end, the best diet is the one that supports your body, mind, and goals—without leaving you drained.
Read More:
Embrace Your Body: Simple Ways to Start Even If You’re Not Quite There Yet
Bad for the Heart: 5 Surprising Foods That Could Harm Your Cardiovascular Health
Portion Control: Debunking the Myth and Exploring Smarter Eating Strategies
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