When I first tried intermittent fasting, I failed - miserably.


The first day, I under ate and couldn’t sleep all night from the hunger. The next day, I was tired, cranky, and grossly over ate. That was when my hunger and hormone roller coaster started. I quit after three days. I felt like a complete and utter failure.


Women Fast Differently

tired, fatigue

My first experiment with intermittent fasting left me tired and lethargic.

Breaking Muscle Shop


If you are a woman, chances are you have experienced this or a similar diet roller coaster at least once - if not dozens of times - in your life. For me, this seemed to be another “lose weight fast” fad, so I quit.


What I didn’t realize back then is that women experience intermittent fasting quite differently than men. It’s sometimes trickier for women to get results. The physiological and weight benefits are still possible, but sometimes require a different approach.


"But how do you fast gradually without throwing your hormones into a frenzy? I find that fasting on nonconsecutive days is better at keeping those pesky hormones in check."

As I looked into why - and the science behind it - I realized that whether you’re male or female, to get that coveted fat loss, you have to customize fasting to you.


For women, in particular, there are specific biological truths about fasting, and if you ignore them, they will keep you from reaching your body and fitness goals. Once I figured out some techniques that bypassed these problems (more on that later), I ended up sharing them with others who experienced the same success.


Why Do Intermittent Fasting at All?

There are actually a good number of science-backed medical benefits to intermittent fasting (IF). First off, studies have shown that IF makes us less insulin resistant. And several studies suggest that people who fast have more energy, better cognition and memory, and increased production of something called neurotrophic growth factor (a protein that promotes neuron growth and protection).


Studies have shown that fasting can improve neural activity.


Fasting intermittently can also prime your cells so they can better handle stressful insults. One study says that a break from eating jolts cells into a minor stressful state, making them more capable of later fending off other types of stress (like the type that can lead to disease.) Lastly, studies among people who participate in Ramadan - a month-long religious fast - say IF may improve immunity, lower diabetes risk, and improve heart health.


In fact, lots of studies on lots of different groups show some cardiovascular, cognitive, diabetes and weight loss benefits on IF. Their major limitation is they tended to be small, short-term studies. Despite that, many in the field are excited about IF’s possibilities.


IF and Hormone Imbalance

You’re probably thinking: What’s the problem? Well, I kind of alluded to that earlier with my failure story. Fasting can be tricky, particularly for women.


In fact, IF may cause hormonal imbalance in women. Women are extremely sensitive to signals of starvation. If the body senses starvation, it will kick up production of hunger hormones. Therefore, when you break the fast, you may experience insatiable hunger. It’s our body’s way of protecting a potential fetus (even when we’re not pregnant). Many of us driven women tend to ignore those hunger cues. Or even worse, we try to ignore them, then fail and binge later, but follow that up with under eating and starvation again. Guess what? All that can halt ovulation.


"All that being said, I think most of you women, even those of reproductive age, will do fine with gentle fasting, as long as when you do eat, you do it healthfully."

In animal studies, after two weeks on IF, female rats stopped having menstrual cycles and their ovaries shrunk; and male rats ended up with lower testosterone production. Insomnia was also more common among female rats.


There are actually very few human studies that have looked at fasting for women specifically, but the animal studies confirm our suspicion: intermittent fasting can sometimes throw off a woman's hormonal balance and cause fertility problems. (And it feeds the negative cycle of eating disorders like anorexia.)


Some signs you’re experiencing hormonal imbalance:


  • Fatigue
  • Depressed mood
  • Bloating
  • Headaches
  • Irregular periods


“Crescendo” Intermittent Fasting

If you find yourself or your clients experiencing any of the above symptoms while doing an intermittent fast - stop immediately. Assuming your symptoms normalize after a couple of weeks, I suggest trying gentle IF. (If you’ve ever heard of the Fast Diet - also known as 5:2 - it is a form of gentle IF.)


But how do you fast gradually without throwing your hormones into a frenzy? I find that fasting on nonconsecutive days is better at keeping those pesky hormones in check. I like to call it Crescendo Intermittent Fasting because you’re gradually working your body until you find the fasting approach that is sustainable for you.


clock, time, food windows

Using "eating windows" can help you achieve the benefits of IF without the hormonal downswing.


Start with a twelve- to sixteen-hour fast on three days a week (but not three days in a row). On those three days you should focus on healthy eating during a restricted window - say, from 11:00am to 7:00pm. Typically, you can achieve this by just skipping breakfast. Make sure to do a shorter training session on fast days. It should be “shorter” for you, so for me that means doing HIIT or something less intense like yoga.


The other thing I believe really helps, but is not absolutely necessary, is branched chain amino acids (BCAAs). BCAAs can keep the building blocks of protein in your system and prevent muscle breakdown. But the biggest advantage I find is that supplementing with them mitigates that ravenous hunger a lot of us have, especially in the beginning stages.


Other Details of Crescendo IF


  • Fast on two to three nonconsecutive days.
  • On fasting days do yoga, strength, or light cardio.
  • Ideally, fast for twelve to sixteen hours.
  • Eat normally on your high-cardio days (that means one or more intense hours of running, biking, metabolic conditioning WODs, etc.).
  • Strongly consider taking 5-8 grams of BCAAs during your fast.
  • Drink plenty of water. Tea and coffee are okay, too.


After you get comfortable with this (after two to three weeks), feel free to fast more often and add nuances like fasting for longer on weekends and for less time on weekdays.


When to Stop Fasting

If you notice any of the negative hormonal imbalance symptoms I mentioned, if you experience problems with your menstrual cycles, or if fasting triggers symptoms of an eating disorder. If any of these things happen, stop immediately - IF probably is not for you.


All that being said, I think most of you women, even those of reproductive age, will do fine with gentle fasting, as long as when you do eat, you do it healthfully.


Fast the Smart Way

As you can tell, I am a big fan of intermittent fasting because of the combination of health and fat-loss benefits. I also think that moving away from the six to eight meals a day dogma is so relieving to many people. No carrying food with you everywhere, no counting calories, no obsessing about every meal, no constant grazing, and so on!


Ladies: If you’re sick and tired of quick fixes that make you less healthy and weaker over the long haul, and if you want to gain the benefits of IF - to feel good, get stronger, and like the body you see in the mirror - then do IF, the smart way.


Check out these related articles:



1. Harvie, M, “The effect of intermittent energy and carbohydrate restriction v. daily energy restriction on weight loss and metabolic disease risk markers in overweight women,” British Journal of Nutrition 2013 Oct; 110(8): 1534-47, doi: 10.1017/S0007114513000792.

2. Martin, B. and Mattson, MP, “Sex-dependent metabolic, neuroendocrine, and cognitive responses to dietary energy restriction and excess,” Journal Endocrinology (2007) Sep; 148(9): 4318-33. Epub 2007 Jun 14z

3. Bronwen Martin, Mark P. Mattson, and Stuart Maudsleya, “Caloric restriction and intermittent fasting: Two potential diets for successful brain aging,” Journal of Ageing Research (2006); 5(3): 332-353.

4. Faris, MA, Kacimi, S, Al-Kurd, RA, Farajeh, MA, Bustanji, YK, Mohammad, MK, Salem, ML, “Intermittent fasting during Ramadan attenuates proinflammatory cytokines and immune cells in healthy subjects," Journal of Nutritional Research, 2012 Dec;32(12):947-55. doi: 10.1016/j.nutres.2012.06.021. Epub 2012 Oct 4.

5. Krista A. Varady and Mark K. Hellerstein, “Alternate-day fasting and chronic disease prevention: a review of human and animal trials,” American Journal of Nutrition, July 2007 vol. 86 no. 1 7-13.

6. Sushil Kumar and Gurcharan Kaur, “Intermittent fasting dietary restriction regimen negatively influences reproduction in young rats: a study of hypothalamo-hypophysial-gonadal axis,” PLoS One, 2013;8(1):e52416. doi: 10.1371/journal.pone.0052416. Epub 2013 Jan 29.


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