Is it good to train on an empty stomach in the morning?

November 24, 2025 •

5 min read

According to a study conducted at Nottingham Trent University, exercising on an empty stomach burned 70% more fat compared to exercising two hours after eating. The question of whether it is good to train on an empty stomach in the morning remains a popular and complex debate in the fitness world, with conflicting evidence and individual outcomes.

Quick Summary

This article explores the benefits and risks of training on an empty stomach in the morning, detailing its effects on fat burning, performance, and muscle preservation. It provides practical advice for those considering this approach, including best practices, hydration tips, and who should exercise caution.

Key Points

Fasted exercise can increase fat oxidation: Working out on an empty stomach encourages the body to use stored fat for fuel, which is a key mechanism for fat loss.
Performance is affected by intensity: While low-to-moderate intensity exercise is well-suited for a fasted state, high-intensity workouts can be compromised by a lack of available glucose.
Muscle preservation is a concern: Without adequate fuel, the body may turn to muscle protein for energy, increasing the risk of muscle loss, especially during intense training.
Proper hydration is essential: Since you aren't consuming food, which contributes to hydration, it is crucial to drink plenty of water and consider electrolytes before and during a fasted workout.
Post-workout nutrition is critical: Refueling with a balanced meal of protein and carbohydrates soon after a fasted session is vital for recovery and muscle repair.
Individual response varies: How a fasted workout affects you depends on your fitness level, goals, and personal tolerance. Listen to your body and adjust your approach accordingly.
Fasted training is not a magical solution for fat loss: Long-term studies show that overall calorie balance and consistency are more important for fat loss than the timing of your workout.

The Core Theory Behind Fasted Training

The concept of fasted training, often referred to as 'fasted cardio,' is based on the idea that exercising after an overnight fast can lead to greater fat oxidation. After fasting for 8-12 hours, the body's glycogen stores—its primary fuel source derived from carbohydrates—are lower than normal. This forces the body to tap into stored fat reserves for energy to fuel the workout.

For many, this sounds like a shortcut to accelerated fat loss. However, while the body does utilize more fat during the workout, this doesn't automatically translate to greater overall fat loss. As research indicates, the body often compensates later in the day, reducing fat oxidation to balance things out. Long-term studies show no significant difference in total fat or weight loss between those who train fasted versus those who eat beforehand, as long as the total calorie balance and exercise intensity are similar.

Hormonal and Metabolic Adaptations

Training on an empty stomach can lead to several hormonal and metabolic changes that are important to understand:

Increased Growth Hormone (GH): Fasted exercise can trigger a spike in human growth hormone, which helps with fat metabolism and muscle preservation.
Enhanced Insulin Sensitivity: Working out in a fasted state can improve the body's sensitivity to insulin. This allows for better regulation of blood sugar levels and can be beneficial for metabolic health.
Elevated Cortisol: The stress of exercising on an empty stomach can also increase cortisol levels. While a short-term increase can aid focus, chronically elevated cortisol can have negative effects, including muscle protein breakdown.

Benefits and Drawbacks at a Glance


Feature	Potential Benefits of Fasted Training	Potential Drawbacks of Fasted Training
Fat Burning	May increase fat oxidation during the workout session itself.	Doesn't necessarily lead to greater long-term fat loss due to compensation later in the day.
Performance	Some report feeling lighter and more focused for low-intensity activity.	Significantly reduced intensity and endurance for high-intensity exercise.
Muscle Preservation	Can preserve muscle mass if total calorie and protein intake are sufficient, aided by increased GH.	Higher risk of muscle catabolism (breakdown) if calories and protein are insufficient.
Convenience	Eliminates the need to plan and digest a pre-workout meal, saving time.	Can lead to dizziness, nausea, or lightheadedness in some individuals.
Lifestyle	Works well for those who prefer morning exercise or follow intermittent fasting.	May lead to overeating later due to increased appetite or cravings.

Fasted Training Best Practices

If you decide that training on an empty stomach in the morning aligns with your goals and how your body feels, it is crucial to follow best practices to minimize risks and maximize benefits. Not all types of exercise are suited for a fasted state, and how you approach it can make a significant difference.

Best Practices for Success:

Prioritize Low-to-Moderate Intensity Cardio: Light to moderate steady-state cardio, like brisk walking, cycling, or light jogging, is most effective when fasted. Since this intensity level relies more on fat for fuel, it is less likely to cause a significant drop in performance.
Listen to Your Body: Pay close attention to how you feel. If you experience dizziness, lightheadedness, nausea, or unusual fatigue, stop the workout immediately. Pushing through these symptoms is not only counterproductive but can be dangerous.
Stay Hydrated: Dehydration can exacerbate the negative effects of a fasted workout. Drink plenty of water before, during, and after your session. Consider adding electrolytes to your water, especially for longer or more intense sessions.
Refuel Correctly Post-Workout: The post-workout meal is arguably more important in a fasted state. Aim for a meal rich in both protein and carbohydrates within 30-60 minutes after finishing. This will help replenish glycogen stores and provide the amino acids needed for muscle repair and growth.
Start Gradually: If you are new to fasted workouts, start with shorter durations and lower intensity. For example, begin with a 20-30 minute walk and gradually increase the length and intensity as your body adapts.

Who Should Be Cautious?

While some individuals may benefit from fasted training, it is not for everyone. Certain populations should exercise caution or avoid this practice altogether.

Strength and Muscle Gain Goals: If your primary goal is to build significant muscle mass or increase strength, training on an empty stomach is not recommended. The lack of available glucose can limit performance and increase the risk of muscle breakdown.
Diabetes and Other Health Conditions: Individuals with diabetes, blood pressure issues, or other metabolic conditions should consult a doctor before attempting fasted exercise, as it can affect blood sugar levels.
Women's Hormonal Health: Some evidence suggests that prolonged or intense fasted training can negatively impact a woman's hormonal balance and menstrual cycle. It is wise to monitor your body's response carefully.
High-Intensity Training: Anyone planning a high-intensity session, such as a HIIT workout or heavy weightlifting, should fuel up beforehand. These activities rely heavily on glycogen, and a fasted state will compromise performance.

Conclusion: The Final Verdict

Ultimately, whether it is good to train on an empty stomach in the morning depends on your specific fitness goals, physical condition, and how your body responds. For individuals aiming for fat loss through low-to-moderate intensity exercise, it can offer a metabolic advantage during the workout itself. However, for those focused on high-intensity performance, strength building, or significant muscle gain, fueling up beforehand is the more strategic choice. Consistency in exercise and overall nutrition remains the most critical factor for long-term success, regardless of whether you train fasted or fed. The key is to listen to your body, stay hydrated, and ensure your post-workout nutrition supports your recovery and goals. What works for one person may not work for another, so personal experimentation and awareness are paramount.

Fasted vs. Fed Workouts: A Comparative Look


Aspect	Fasted Workout	Fed Workout
Energy Source	Primarily relies on stored fat and glycogen reserves.	Primarily utilizes recently consumed carbohydrates and glucose.
Primary Goal	Often associated with maximizing fat oxidation for weight loss.	Optimal for maximizing performance, strength, and muscle growth.
Workout Intensity	Best for low to moderate intensity and duration.	Supports high-intensity and longer-duration workouts.
Muscle Preservation	Potential risk of muscle catabolism if not managed correctly.	Provides necessary nutrients (protein) to prevent muscle breakdown.
Recovery	Crucial to refuel immediately post-workout to replenish stores.	Recovery process begins sooner with pre-workout nutrients.
Side Effects	Risk of dizziness, nausea, and reduced focus due to low blood sugar.	Potential for digestive discomfort if the pre-workout meal is too heavy or eaten too close to the session.

Frequently Asked Questions

Exercising in a fasted state can increase the rate of fat oxidation during the workout itself. However, studies show that this doesn't necessarily lead to a greater overall reduction in body fat long-term, as the body can compensate by burning less fat later in the day.

Exercising in a fasted state every day can carry risks, especially with high intensity or long duration. It can lead to fatigue, muscle loss, and hormonal imbalances over time. For most people, it is not recommended to do intense fasted workouts daily.

Low-to-moderate intensity steady-state cardio, such as brisk walking, light jogging, or cycling, is best suited for exercising on an empty stomach. These activities rely more on fat for fuel and are less likely to cause fatigue or reduced performance compared to high-intensity workouts.

Lifting weights on an empty stomach is generally not recommended, especially for those seeking to build muscle or strength. High-intensity resistance training depletes glycogen stores quickly, and a fasted state can lead to reduced performance and increased risk of muscle catabolism (breakdown).

After a fasted workout, it is essential to have a nutrient-dense meal within 30-60 minutes. Your meal should contain a mix of lean protein and quality carbohydrates to replenish glycogen stores, repair muscle tissue, and kickstart recovery.

Potential risks include reduced workout performance, increased risk of muscle breakdown, low blood sugar (hypoglycemia) leading to dizziness or nausea, and hormonal disruptions, particularly for women.

Drinking black coffee before a fasted workout is common and can be beneficial. Caffeine can enhance energy levels and focus without breaking the fasted state. However, it's important to monitor your intake and ensure you're also drinking plenty of water.