Nutrition for performance

Intermittent Fasting: Weight Loss, Recovery and Performance

Whether you’re a die-hard, competitive Crossfitter, or you’re just breaking into the Crossfit scene, you’ve probably heard the term 'Intermittent Fasting' floating around your box or local gym. And rightfully so.

While it used to be reserved for only elite bodybuilders and fitness models, Intermittent Fasting provides untapped performance and health benefits (and yes, aesthetic perks, too!) that are making it gain serious traction among mainstream athletes.

But as with any new fitness ‘trend’, Intermittent Fasting is still a hot topic of debate:

  • ‘Won’t it hurt my performance?’
  • ‘Don’t I need to fuel up first thing in the morning?’
  • ‘Is it even…healthy?’

While the finer details are beyond the scope of this one article, let’s learn the basics, clear up the confusion, and discover if Intermittent Fasting is right for you.


Before we dive in, let’s address the elephant in the room… Intermittent Fasting has a disgustingly horrible name, for what’s really a simple concept. If I had to guess what it was, purely from the name, I’d say it sounds like starving yourself off-and-on for who knows how long.

Agonizing, right?

‘Good news! Intermittent Fasting is simple: Keep your meals to an 8-hour window during the day, and you’re golden.’

This puts you in a ‘fed state’ for 8 hours and a ‘fasted state’ for 16 hours, hence the name.

intermittent fasting foods kiwi avacado leeks

intermittent fasting requires healthy, wholesome foods

For women, 10 hours in the ‘fed state’ and 14 hours in the ‘fasted state’ is ideal to begin with. From a hormonal perspective, ladies tend to see a slight increase in irritability and food cravings when they hop right to 16 hours of fasting, so starting with a 14-hour fast, and then shifting over to 16 is your best bet for a smooth transition.


I won’t get too far into the weeds in this post, but the benefits include added convenience, lower blood sugar levels, increased insulin sensitivity – and did I mention, lower body fat percentages?

Eating 5-6 small meals a day is pretty much the norm amongst Crossfitters, due to claims that it’ll keep blood sugar in check, but a careful look shows that having more frequent meals actually elevates your baseline blood sugar levels ¹. Higher blood sugar levels lead to insulin resistance and glucose intolerance as well. By allowing you to eat fewer (and yes, larger) meals in a shorter time span, Intermittent Fasting keeps blood glucose, insulin intolerance, and glucose resistance all in check.

intermittent fasting protein salmon salt tomato

Make your meals bigger, but in a shortened time window

But it gets better…

Increased insulin sensitivity also means increased leptin sensitivity. Leptin is the signal that tells our brains we’re full, and our bodies to stop storing fat, so we want to be sensitive to it– the sooner our bodies hear that leptin signal, the sooner we’ll put the fork down. Increased leptin sensitivity (and thus, lower body fat levels) is yet another benefit of Intermittent Fasting.

Not to mention, eating all 3 meals in an 8-10 hour span increases your satiety, meaning it’ll be a lot easier for you to put down that extra cookie!

Now that you’ve got the basics of Intermittent Fasting down, let’s get to the good part.


The short answer: probably.

The easiest and most common way to get started (and the way that’ll produce the most benefits) is by simply skipping breakfast. Sounds sacrilegious, right? Even a little scary?

I get it.

We’ve all heard that ‘breakfast is the most important meal of the day’ and it seems to be a consensus among the fitness community. Let’s be real, though: When you’re swamped, miss your alarm, or you’re working off last night’s food baby, breakfast is the first thing to go.

intermittent fasting foods tomato egg nuts carrot

intermittent fasting works best with healthy, natural foods

But more and more people are actually making it a habit. And if you work out early like I do, you might have already nixed it from your morning routine. If that sounds like you, then Intermittent Fasting might be your new best friend. Either way, let’s dive in and see how Intermittent Fasting can work with (and even streamline) your day-to-day schedule:


You’re an early riser, and you’ve got limited time before your busy day starts. You’re likely choking down some form of ‘breakfast’, pre-workout. Whether it’s a sports gel, a protein shake, or a banana, odds are, pounding down food at this hour before a gut-wrenching workout is not your stomach’s idea of ‘fun’.

Good news: Intermittent Fasting is most effective when you skip breakfast! Instead, sip down a glass of water and 10g BCAA. Immediately post-workout, refuel with 10g BCAA and repeat every few hours as needed until lunch time when your feeding window begins.

crossfit girl muscle up diet intermittent fasting

nutrition and diethave a huge influence on performance

© RX'd Photography


Middle-of-the-day workouts are sweet magic for I.F. Crossfitters, because you’ll get to break the fast with your largest meal of the day: the post-workout refeed.

Fuel up pre-workout with 10 BCAA, and after your workout, pair 10g BCAA with your post-workout feast. Don’t be afraid to throw in a few bites of your favorite dessert, too (even if you’re watching what you eat).


You’ve likely already had a meal or two by the time you hit the pavement. Depending on your schedule and preferences, break the fast around 12-2, and schedule your largest meal for right after you exercise.

If you’re eating lunch before your workout, break the fast with a high-protein meal to keep you on your feet. If you’ve already got a groove going on about what sits best with your stomach, don’t feel like you need to change it up! Leave your third and final meal to be slightly smaller than the other two.


You do take them, right?

On a rest day, simply break the fast around 12-2 (or whenever you typically do), swapping in extra protein in your first meal for a slight reduction in carbs later in the day. Keep your feeding window the same as the other days, and you’re all set to become an Intermittent Fasting fiend!


No matter when in the day you squeeze in your workouts, the aesthetic perks, health benefits, and convenience all make Intermittent Fasting a Crossfitter’s new best friend.

Source ¹ Holmstrup, Michael E., et al. “Effect of meal frequency on glucose and insulin excursions over the course of a day.” Clinical Nutrition ESPEN 5.6 pp e277–e280. Dec. 2010. Web.