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Should You Eat Before Exercise? Exploring the Relationship Between Fasting, Exercise, & Your Goals

eat before exercise; breakfast before workout


I'm often asked by my friends and clients whether it's better to exercise on an empty stomach. The idea of burning excess fat through fasted exercise, particularly in the early morning, is a common topic of interest.

But is it truly beneficial to jump into a workout without having breakfast? The answer, as you might expect, isn't a simple 'yes' or 'no.' It depends on various factors, including the type and duration of exercise, your fitness goals, typical dietary habits, and the duration of your fasting period.

In this blog post, we'll delve into the pros and cons of exercising in different states, aiming to provide insights that will serve as practical guidelines for your fitness routine. Let’s start by understanding the underlying mechanisms.

Metabolic Impact of Fasting as it Relates to Exercising:

Our bodies store energy in various forms, including glycogen from carbohydrates and fat. When we exercise, the body draws on these stores for fuel. Drawing energy from muscles is much harder to do and is often a last resort for your body.

Fasted exercise, typically occurring after a 10-14 hour fasting period, prompts the body to rely more on fat for fuel. The body turns to stored fat for energy since glycogen levels are lower. This can enhance fat burning during the workout. Additionally, exercising in a fasted state further improves glucose balance and insulin sensitivity, which is a desirable end goal for anyone looking to achieve improved health outcomes.

On the other hand, exercising after eating means there's readily available glycogen for energy, which can be helpful for longer or more intense workouts. Caution, though; eating too close to exercise time may also lead to discomfort and indigestion, as many of you will have personally experienced.

Weight Loss or Muscle Building?

Exercising while fasted seems to be a helpful lever for weight loss, especially in the form of fat loss. However, note that this is only true for workouts that are on the shorter, less intense side, like a 30-minute run or an hour’s Pilates session. High-intensity or extended training sessions may benefit from sufficient glycogen stores to get the best performance and protect against over-exhaustion.

If your goal is to build muscle, then ensuring a sufficient intake of protein and nutrient-dense foods throughout the day is essential to aid in the repair and recovery of muscles post-workout. Fasting in this instance, if you do not have excess fat stores, will mean that you will be tapping into your muscle stores, defeating the point of working out for muscle-building. So, eating before strength training is a personal preference, but eating high-protein foods afterward is a must for great results.

Length of Fast Matters; As Does Where You Are in Your Cycle

It's essential to acknowledge that the duration of your fast plays a role in deciding whether to exercise or not. Extended periods of fasting, above 16 hours, may impact energy levels and muscle preservation. Therefore, it is essential to only engage in moderate to low-intensity exercise like walking and yoga while on longer fasts.

Additionally, cycle syncing for women is super relevant in the case of fasting and high-intensity exercise. Generally, engaging in extended fasts and more strenuous workouts is advisable only from Day 1 to about Day 20. The week leading up to your period is usually best taken a lot easier, with minimal or no fasting and a very moderate exercise routine.

My Own Personal Preference, as a Health Coach

When I am planning to exercise in the early morning, I tend to do so on an empty stomach, barring a cup of black coffee. I feel lighter, more energized, and motivated. If I am exercising later in the day, I will typically have a snack in the form of a handful of nuts with some yogurt to keep me nourished without feeling sluggish. Having a high-fat, high-protein snack helps keep my glucose levels in balance and gives me the much-needed energy boost for the workout ahead.


In conclusion, the decision to exercise in a fasted state or not ultimately boils down to personal preference. If you feel more invigorated and motivated to work out while fasting, go for it. If you find that eating beforehand enhances your energy levels, and does not jeopardise your health goals, then that's the right approach for you.

The key takeaway is that the act of exercising itself is crucial – whether in a fed or fasted state, any effort is better than none. Listen to your body, choose what aligns with your goals, and keep moving toward a healthier you.

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Thank you!

Nada Soubra

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1 Comment

Loved reading this blog (and your other insightful blogs). I always go to exercise after breakfast, because I hate feeling hungry. But to lose fat, I should be going before breakfast with a black coffee.... now that's is something I am going try out!

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