You know that fueling up before and after workouts is necessary to be a strong, healthy athlete. But what if you could be a healthier person by skipping your pre- or post-workout meal in favor of a short fast?
Intermittent fasting is a practice where you go without food for a set period of time. Intermittent fasting is associated with a number of health benefits, including a decreased risk of developing obesity, diabetes, high blood pressure, heart disease, and cancer.
If you haven’t tried intermittent fasting, it’s always best to start with a moderate approach. (Compare it to cardio or resistance training — you didn’t jump right into 10K runs or doing 25 interrupted push-ups during your first workout, did you? Of course not!)
Below, I dive further into what intermittent fasting is and how to work it into your training routine. In addition, I’ll explain a few intermittent fasting meal plans suitable for beginners, and how to adjust as you become more familiar with the practice.
Please note: This post is meant for informational purposes only, and should not be taken as medical advice. If you are considering trying intermittent fasting for the first time, please consult your physician or dietitian.
What Is Intermittent Fasting?
Intermittent fasting is the practice of going without food for a set period of time.
Every night, every single one of us fasts from dinner to breakfast (that’s where “breakfast” gets its name — you are breaking a fast). If you skip a meal throughout the day — such as foregoing breakfast or going to bed without dinner — this is also a fast.
There are numerous approaches to intermittent fasting (which I’ll dive into below). A fast can be as short as 8-10 hours, or extend over the course of several days.
It’s important to note that there is no “right” or “wrong” way to approach intermittent fasting — there are only those methods that work best for you. While intermittent fasting, it’s important to listen to your body, gauge your energy levels, and pay attention to how intermittent fasting impacts your workouts.
Intermittent Fasting Meal Plan: How to Approach Your First Time
While fasting, you split your time between a "fasting window" and an "eating window." Typically, those new to fasting will begin with a moderate fasting window, such as 12-14 hours (with an eating window lasting 12-10 hours, respectively). As you become more comfortable with fasting, you will expand your fasting window to 16- or even 24-hour periods.
1. Skip a Meal
If you have never fasted before, I highly recommend starting with simply skipping a meal.
You can skip a meal sporadically, choosing not to eat if you’re not hungry. Or, you can skip a meal routinely, choosing to skip the same meal every day of the week. For example, you can skip breakfast, having lunch as your first meal of the day. Or, if you have a late lunch one day, you can skip dinner.
2. The 16:8 Method
As you become comfortable with skipping a meal, you want to progress to the 16:8 method.
With the 16:8 diet plan, you will eat within an 8-hour window, fasting the remaining 16 hours of the day. For example, you could have your first meal at 10 a.m. and your last meal at 6 p.m., then fast until you start your morning routine the next day. Or, you could skip breakfast daily and begin with launch, eating between noon and 8 p.m.
3. 24-Hour Fast
If you feel comfortable fasting for 16 hours straight, you might want to extend your fasting period to a full 24 hours.
If you fast for a full 24 hours, you should only conduct one fasting day per week. In other words, you could fast every Monday, eating normally the remaining six days of the week.
Some individuals fast for two full days per week (called the 5:2 fasting diet), but I don't recommend it. If you follow a regular fitness routine — such as the Build Bullet-Proof Health program — fasting for two 24-hour periods could negatively impact your recovery time and energy levels.
4. Alternate-Day Fasting
The last and most advanced intermittent fasting plan is alternate-day fasting. Like the name entails, you will fast every other day of the week.
If you follow an alternate-day fasting plan, you can restrict your calorie intake to 500 or less on fasting days (rather than going multiple days completely without food). On non-fasting days, you will follow a normal, healthy eating plan.
Intermittent Fasting Meal Plan FAQs
Science shows intermittent fasting comes with a number of health benefits. With that being said, going extended periods without food is both a physical and mental challenge.
My best advice when intermittent fasting is to start small, and increase your fasting window only when you feel comfortable. If you haven't tried intermittent fasting before, here are a few answers to frequently asked questions to help get you started:
- Can I eat anything while fasting? Technically, no. You can drink water and black coffee or tea, but you shouldn't consume anything with calories. (The one exception is the alternate-day fasting plan, where you can eat a few smaller meals, not to exceed a few hundred calories on your fasting days.)
- Should I follow a low-calorie diet on non-fasting days? No. You should eat healthy, whole foods during your eating window, eating quality protein (like fish or chicken), plenty of fiber (with fresh fruits, whole grains, and veggies), and healthy fats (such as nuts, seeds, avocados, and olive oil).
- Should anyone not try fasting? Intermittent fasting comes with very few side effects for most people. However, you should not try fasting if you have chronically low blood sugar, are pregnant, or have a history of eating disorders.
- How should I balance intermittent fasting and my workouts? I don't recommend fasting before an extremely hard workout. Therefore, try to pair your fasting days with your rest and recovery days.
- Does fasting mean I don't have to worry about calorie restriction? No. Your caloric balance still remains the most important metric. While I don't recommend constant counting calories, you should listen to your body, and pay attention when it says it's full. Fasting one day is no reason to gorge on junk food the next day.
- Will I experience weight loss while fasting? Most likely. Many people experience fat loss and reduced body weight while fasting. However, I don't recommend focusing on losing weight during your eating window. Instead, focus on making wise, healthy food choices.
Lastly, keep this in mind: Intermittent fasting has many benefits, but it’s not a silver bullet.
When trying to lose weight or improve your body composition, your caloric balance (calories in vs. calories out) and macro split (carbs, fat, and protein) are what matter most. Intermittent fasting is one method to achieve this, but is not better or worse than any other weight loss method.
Remember: The caloric balance and macros are the constants. The diet is just the variable.
Try Intermittent Fasting to Experience a Number of Health Benefits
Intermittent fasting can cut body fat and reduce your risk of developing a number of medical conditions, not limited to heart disease, obesity, and diabetes.
While the benefits of fasting are immense, going long periods without food can be extremely daunting. If you haven't tried intermittent fasting before, my best advice is to start small, and gradually increase your fasting window over time.
Skipping a meal or following the 8:16 intermittent fasting diet are two great approaches for beginners. If you feel comfortable with either of these methods, you can slowly decrease your eating window until you reach 24 full hours of fasting.
If you are following a regular workout program — like the Build Bullet-Proof Health program — I recommend pairing your fasting days with your active recovery days. If you want tailored advice for starting intermittent fasting, sign up for the Premium Membership where you receive a monthly face-to-face call with me. During our call, we can discuss how intermittent dieting fits into your training schedule.
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