Fasting for non-religious causes – and whether or not it’s good or dangerous for you – has turn into a scorching matter within the well being and health area. Everybody has an opinion they usually appear to be getting increasingly obsessed with it by the day.
Soar into the feedback part of an Instagram submit of fasting and also you’ll see what I imply.
Personally, I get up HUNGRY.
My sister can’t have a look at meals earlier than midday.
I really feel like crap if I don’t eat earlier than figuring out.
My buddy Jules seems like crap if she does eat earlier than figuring out.
Way back to 2019, “intermittent fasting” was some of the searched diet-related phrases on Google and the subject solely appears to have heated up since then.
With all of the hype round fasting, particularly for girls, it’s straightforward to get caught up within the development. However right here’s the factor: fasting for girls isn’t so simple as it might appear.
After diving into the analysis, my largest takeaway is that this: Regardless of your opinion on fasting, you’ll seemingly discover analysis to help your perspective. However on the subject of fasting for girls, we have to think about some essential components, from the research gaps to how fasting impacts lively girls’s wants for vitality, muscle restoration, and hormonal stability. Right here’s what you need to know.
What Is Fasting, Actually?
Fasting merely means taking a break from consuming (and typically ingesting) for a set time frame.
Technically, all of us quick in a single day whereas we sleep—and that fasting window is definitely essential! It offers our our bodies time to relaxation, restore, and faucet into saved vitality as a substitute of regularly processing new meals. And breakfast is actually the meal once we break the in a single day quick.
This pure “pause” requires that our our bodies expend glucose and fatty acids circulating in our blood and faucet into vitality shops. It trains our our bodies to get higher at processing vitality.
However What About Longer Fasts?
Some folks deliberately stretch that in a single day quick into an extended break, a observe generally known as intermittent fasting (IF). Probably the most widespread variations is known as time-restricted consuming (TRE), the place you restrict your consuming to a selected window – typically round 8 hours (or much less) – and quick the opposite 16 hours of the day.
For instance, you would possibly eat dinner at 6 p.m. after which not have any extra energy till 10 a.m. the following day—so that you just’re fasting in periods of low or diminished exercise.
There’s a Lack of Analysis on Fasting for Ladies
Many of the analysis on fasting has been accomplished on males and lots of have solely been accomplished on animals. Individuals who help fasting typically make the leap that findings of these research apply to girls as properly, however that’s a reasonably large leap as a result of girls’s our bodies reply in a different way than males’s (or mice)—particularly on the subject of diminished calorie consumption, our hormonal cycles, and train.
The huge majority of research on fasting for girls give attention to sedentary girls and people think abouted chubby or overweight. However with small pattern sizes it’s exhausting to generalize the findings to lively girls and those that should not thought of chubby or overweight.
We do see that for many who are inactive or sedentary, research have proven fasting generally is a useful stressor on the system that helps enhance insulin sensitivity, glucose metabolism, amongst different issues.
However if you’re an exerciser or an lively girls or in perimenopause, there’s a main hole within the analysis that makes it even more durable to use the present fasting analysis to your life—particularly on the subject of understanding how fasting impacts train efficiency and restoration.
Fasting for Weight Loss
The analysis on fasting and weight reduction is kind of clear: on the finish of the day, on the subject of weight reduction, fasting is actually only a technique of calorie restriction. Whereas proponents declare fasting has particular metabolic advantages, there’s no strong proof exhibiting that it’s any more practical than different types of calorie management, like portion management, tracking your food intake, or balanced consuming.
Fasting is only a technique of decreasing your calorie consumption by utilizing the clock to restrict your consumption. And when calorie consumption is managed for, fasting isn’t higher than different “diets” for reaching long-term weight reduction or well being enhancements.
Fasting and Train
Combining fasting and train is the place it will get tough—particularly for girls. Primarily, it is because fasting and train do related issues—they each lower your blood glucose and different essential molecules circulating in your blood.
So whenever you mix them and train whereas fasted, you would possibly find yourself with some points.
First, for each women and men, exercising fasted might make your blood sugar ranges go too low and depart you making an attempt to actually run on an empty tank. No gasoline makes it actually exhausting to work out or work out exhausting sufficient to get the outcomes you’re after. It might additionally make you dizzy and cross out.
Second, fasted train is related to decreased efficiency, elevated fatigue, diminished talent, impaired focus, and an elevated notion of effort (so train feels more durable than it ought to). This makes it much less seemingly that you just’ll have good coaching classes and even need to work out.
Moreover, muscle preservation is important for general well being and metabolism, and fasting alone might not do the job in addition to different consuming methods that prioritize protein and carbohydrates for muscle restoration and progress.
For girls who do select to quick or exercise fasted, it’s essential that they proceed to give attention to consuming enough meals – particularly protein and carbs – all through the day throughout their feeding window to attenuate the chance of low vitality availability and stop muscle breakdown and loss.
Self-Consciousness: The Key to Making Good Fueling Decisions
Whether or not you’re fasting or following one other consuming plan, self-awareness is important. Everybody’s physique is completely different, and meaning tuning into your private wants and the way your weight loss program (and train) impacts your vitality, temper, and efficiency.
And context issues—so do not forget that it’s not nearly skipping that one meal, it’s about the way you’re balancing your wants throughout the day as properly. So what works for one individual, might not be just right for you. And what used to be just right for you, might someday not be acceptable or efficient.
Some girls thrive on fasting, however many others discover that under-eating or fasting interferes with their exercises and restoration.
Everybody’s physique has distinctive wants, and there’s no one-size-fits-all method.
Once I introduced up the subject of fasting to my colleague, Jules Mitchell, writer of Yoga Biomechanics: Stretching Redefined, she shared how difficult it may be for individuals who weren’t athletes rising as much as acknowledge their physique’s indicators.
“The older I get, the extra privileged I really feel for having performed sports activities as a child and spent my childhood operating races. At eight years outdated, I realized {that a} half banana earlier than a 10k would make me sick. I’ve been listening to my physique’s indicators my complete life. However in case you’re simply now in perimenopause and stepping into train, all of the blended messaging have to be so complicated.”
Her expertise reminds us that self-awareness isn’t nearly noticing what we really feel right this moment—it’s about understanding how our our bodies reply over time, by completely different phases of life and exercise.
Should you’re consistently feeling drained, weak, or sluggish throughout your exercises, it may be an indication that you just’re not fueling your physique correctly.
Self-awareness is about listening to your physique and making changes primarily based on how you’re feeling, not simply following the affair development.
Many Lively Ladies Are Typically Below-fueled
One of many key factors that always will get ignored on the subject of fasting for girls is the difficulty of under-fueling.
Many lively girls underestimate their whole day by day vitality expenditure (due to all these foolish 1200-1500 calorie weight loss program suggestions that we grew up with) and find yourself consuming too little to satisfy their vitality calls for. That is very true for girls who do common energy coaching, high-intensity exercises, or endurance coaching.
A 2016 examine performed on 109 feminine leisure exercisers discovered that 45% had been in danger for low vitality availability – that’s practically half of the ladies recruited from native gyms and health facilities had been in danger on account of under-fueling.
So under-fueling and low vitality availability aren’t only a concern for “high-level” athletes, any exercising girl might be in danger.
Below-fueling can result in poor restoration, decreased efficiency, and even hormonal imbalances. Ladies who practice exhausting want to make sure they’re consuming enough carbohydrates and protein to gas their exercises and get better successfully. With out the correct vitamins, your physique can’t rebuild muscle, and you could expertise fatigue, temper swings, and hormonal disruptions.
In my work as a private coach serving to girls with osteoporosis construct and keep bone mass, most of my discussions with purchasers encompass consuming extra, not much less.
Dietary Therapist Michaela Smith agrees. She shared her ideas with me:
“The overwhelming majority of ladies I work with are under-fueling already, even those that want to drop extra pounds! Below-eating is a major stressor that may manifest into hormonal imbalance, weight modifications, and even cognitive modifications.”
In her observe, she typically doesn’t suggest intermittent fasting for girls. Right here’s why:
- Many ladies are already under-eating, which might contribute to nervousness, mind fog, overwhelm, and hormonal imbalances.
- Fasting can negatively have an effect on blood sugar, resulting in:
- Drops in blood glucose
- Launch of stress hormones
- A rebound spike in blood sugar
- A “blood sugar curler coaster” that leaves girls feeling off stability when it comes to vitality and meals cravings
- There may be restricted analysis on the consequences of fasting on girls, making lengthy fasts a questionable technique.
As an alternative, Michaela recommends the next method to help regular vitality and hormonal well being:
- Eat a balanced breakfast inside 30–60 minutes of waking.
- Gas persistently all through the day with common meals and snacks.
- End dinner early sufficient to permit time to digest and profit from a delicate in a single day quick.
- Intention for a 12-hour window between dinner and breakfast—this helps vitality metabolism and intestine well being with out over stressing the physique.
“The long-term outcomes I see with the ladies I work with are extra even vitality, fewer jittery emotions, improved blood sugar response, and extra steady weight. All wins in my ebook!”
When You Eat Issues, However So Does What You Eat
Whereas timing your meals or solely consuming inside a selected window may appear fashionable, it’s extra essential to give attention to what you eat and whether or not it meets your physique’s wants. Whether or not you’re consuming earlier than or after your exercise, ensure you’re getting sufficient carbohydrates to gas your train and protein to get better.
Carbohydrates are your physique’s major supply of gas for train, and you should replenish glycogen shops after exercises. The amino acids in protein are the constructing blocks for all tissue and helps rebuild muscle, keep bone, and help restoration.
For lively girls, this stability is essential—irrespective of whenever you eat. It’s all about giving your physique the vitamins it must get better and carry out at its greatest.
Should you’re not used to consuming earlier than you’re employed out, however you need to attempt it, begin small with simply 100 energy of easily-digestible, low-fiber carbs or a sports activities drink to keep away from GI misery. Then, over time steadily improve the energy to coach your system to tolerate meals at the moment of day.
Fasting and Hormonal Well being: A Complicated Relationship
For girls with polycystic ovary syndrome (PCOS), intermittent fasting has proven some promising advantages in enhancing insulin sensitivity, regulating blood sugar ranges, and selling hormonal stability. A number of research have recommended that fasting can cut back insulin spikes, a key subject in PCOS, and will assist alleviate signs like irregular menstrual cycles, weight achieve, and pimples.
Nonetheless, it’s essential to notice that almost all of the analysis on fasting for PCOS has been performed on chubby or overweight premenopausal girls and the findings are nonetheless rising. Whereas the outcomes are encouraging, extra analysis is required to know how intermittent fasting impacts girls with completely different physique varieties and at varied levels of life, together with those that are lively and in perimenopause or past.
For lively girls, particularly these in perimenopause, fasting can influence hormonal stability in ways in which will not be instantly obvious. Low vitality consumption, particularly when mixed with a number of train, can result in low vitality availability and/or finally Relative Vitality Deficiency in Sport (RED-S), a situation that impacts reproductive, metabolic, and bone health. Indicators of RED-S can embrace menstrual irregularities, fatigue, decreased bone density, and poor restoration.
And right here’s the kicker: throughout perimenopause, distinguishing between anticipated hormonal modifications and the indicators of RED-S might be tough.
Should you’re experiencing fatigue, poor restoration, or irregular durations (which many ladies gained’t even be capable of inform in the event that they’re utilizing contraception that alters their interval), it may very well be an indication that you just’re not fueling sufficient to help your exercises and general well being.
Sufficient fueling, particularly with carbohydrates, is particularly essential in midlife to help each coaching and hormonal well being.
Conclusion: Fasting for Ladies—A Personalised Strategy
Fasting may go for some girls, however it’s essential to do not forget that, on the subject of weight reduction, it’s only one technique of calorie restriction and it hasn’t been confirmed to be more practical than different dietary methods.
For lively girls, self-awareness and listening to how you’re feeling throughout exercises and restoration are essential. Earlier than contemplating a fasting routine, make certain your physique is well-fueled.
A balanced consumption of carbohydrates and protein is important—particularly to help your exercises, restoration, and general well-being. Below-eating could make fasting counterproductive—rising stress on the physique slightly than supporting well being.
And in case you’re very lively or an athlete with targets—working towards a PR in your lifts or coaching for a contest or race—you could need to depart fasting within the mud as it will probably lower your efficiency and inhibit your restoration.
There’s no one-size-fits-all method. The perfect technique is well-thought-out and helps your vitality, efficiency, and long-term well being—not one which leaves you depleted.
And bear in mind that there’s a rising variety of “medical doctors” and specialists on the market who’re talking about fasting (and benefiting from it) despite the fact that it is rather a lot out of their very own scope of observe. So earlier than diving in head first, make certain you test what sort of physician they’re and confirm that you just solely take recommendation from certified diet specialists.
Should you’re uncertain the place to start out, think about getting help from a registered dietitian or nutritionist who specialise in working with girls in your particular inhabitants (lively, endurance athletes, and/or perimenopausal girls) to assist tailor a plan that works for you. —Karin
References
- Vitality Professional. (2019). “Intermittent Fasting: A Search Pattern.” Vitality Professional Vitamin Statistics. Link
- Cienfuegos, S., et al. (2022). “Intermittent Fasting and Reproductive Well being: The Potential Results.” Vitamins.
- Correia, M., et al. (2020). “Intermittent Fasting and Cardio Efficiency.” Journal of Sports activities Sciences.
- Batitucci, G., et al. (2022). “The Influence of Fasting on Muscle Mass and Physique Composition.” Frontiers in Vitamin.
- Zouhal, H., et al. (2020). “Results of Fasting on Train Efficiency: A Evaluation.” Sports activities Drugs.
- Mellin, A. (2025). “Carbohydrate Availability and Menstrual Well being in Lively Ladies.” Journal of Sport Vitamin and Train Metabolism.
- Aird, L., et al. (2018). “Fasted vs Fed Train: The Influence on Fats Metabolism and Efficiency.” Worldwide Journal of Sports activities Physiology and Efficiency.
- Slater, J., et al. (2016). “Feminine Leisure Exercisers at Threat for Low Vitality Availability.” Worldwide Journal of Sport Vitamin and Train Metabolism.