Fasted Cardio for Optimal Weight Loss??

The fitness world often hypes fasted cardio as a secret weapon for weight loss. But does exercising on an empty stomach really lead to more fat burning? Let's dive into this topic and explore what science says about fasted cardio and its impact on weight loss.

What is Fasted Cardio?

You perform fasted cardio when your body is not digesting food, essentially doing cardio on an empty stomach. This typically occurs in the morning after an overnight sleep or later in the day for those practicing intermittent fasting. Fasted cardio, compared to nonfasted cardio, claims to accelerate fat loss. However, its effectiveness remains unproven. Let's delve deeper into this.

The Theory Behind Fasted Cardio

Bodybuilder and author Bill Phillips made fasted cardio popular in his book "Body-for-LIFE." He said that exercising without eating first burns more fat. This happens because your body's glycogen, a type of stored carbohydrate, is low after not eating overnight, so your body uses stored fat for energy instead. Despite its popularity, experts continue to debate the effectiveness of fasted cardio for optimal weight loss. Let's examine the research conducted to test the ideas behind fasted cardio.

Assessing the Safety of Fasted Cardio

For most healthy individuals, incorporating short or moderate-length steady-state fasted cardio sessions into a routine is safe. However, extended periods of exercise or high-intensity workouts during fasted cardio can pose risks due to potential low blood sugar or dehydration side effects, like lightheadedness, dizziness, shaking, or fainting. For more on safe exercise practices, check out our Effective Workout Plan.

Understanding the Benefits of Fasted Cardio

The rationale behind fasted cardio is that exercising after an overnight fast depletes your body of glucose, its primary energy source, leading it to use stored fat for fuel. Research on this approach's effectiveness is mixed. One review indicated that fasted exercise led to higher metabolic performance post-workout. However, for prolonged aerobic activity, eating before the workout improved performance.

Fasted cardio offers potential benefits:

• Saves Time: It eliminates the need to prepare, eat, and digest a meal beforehand.
• Aligns with Intermittent Fasting: It allows exercise before the day's first meal, fitting well with intermittent fasting schedules.
• Personal Preference: Some prefer working out on an empty stomach, especially if they have a sensitive stomach or feel more energetic without a pre-workout meal.

Does Fasted Cardio Aid in Weight Loss?

The key to weight loss is burning more calories than you consume. Research on whether fasted cardio promotes fat loss is mixed.

In one study, researchers divided 20 young females into two groups: one did 1 hour of fasted steady-state cardio, and the other did 1 hour of nonfasted steady-state cardio, three days a week for four weeks, with a calorie deficit diet. They found no difference in weight loss or body composition between the groups.

However, some research supports increased fat-burning effects during fasted cardio workouts. A review of 27 studies in the British Journal of Nutrition concluded that "aerobic exercise performed in the fasted state induces higher fat oxidation than exercise performed in the fed state." This research shows that while fasted cardio may burn more calories during the session, its impact on total daily calorie expenditure over 24 hours is minimal.

Increasing daily movement (non-exercise activity thermogenesis, or NEAT) is the best strategy for optimal weight loss, accounting for about 15% of daily calorie burn depending on activity level. For personalized advice, use our Calories and Macro Calculator.

Risks Associated with Fasted Cardio

Fasted cardio has benefits but also risks:

• Muscle-Building Hinderance: If insufficient carbohydrates are available for energy, your body starts gluconeogenesis, converting protein into fuel, leaving less protein for muscle rebuilding. Low-intensity steady-state cardio may be better than high-intensity exercise in a fasted state, as your body uses free fatty acids for fuel rather than burning carbohydrates.
• Performance Issues: Without fuel, energy levels for moderate or high-intensity workouts like HIIT or weight training are not optimal. Watch for signs of low blood sugar and dehydration. Learn more about how to maximize your workouts in our article on the Benefits of Strength Training for Weight Loss.

Who Should Avoid Fasted Cardio?

Avoid fasted cardio if you have medical conditions affected by low blood sugar or blood pressure, or if you're pregnant. If you feel unwell during a fasted workout, stop and eat a balanced meal, and follow up with a healthcare provider if needed.

Ultimately, the choice to practice fasted cardio is a personal one. Performing exercise consistently, whether fasted or not, provides clear health benefits, including healthy, sustainable weight loss. If you're new to fasted cardio, start slow and give your body a chance to adapt to any changes in your exercise and eating plan. Find what works best for you and your lifestyle.

Guidelines for Fasted Cardio

If you're healthy, deciding to incorporate fasted cardio is personal. Start slowly if you're new to it:

• Hydrate before and during the session.
• Try a low to moderate intensity steady-state session for 10 minutes and gauge your response. Gradually increase to 30 minutes.
• Refuel with a balanced meal or snack packed with protein and carbs post-workout.
• Avoid high-intensity work or sessions longer than an hour during fasted cardio.
• Include low-intensity steady-state fasted cardio on multiple days, but ensure 1 or 2 rest days weekly.

Eating After a Fasted Workout

Post-workout nutrition is crucial. After your fasted workout, you should eat a balance of protein and carbohydrates within an hour.

• Eggs and whole wheat toast
• Oatmeal with yogurt
• Chicken and rice
• Salmon and quinoa

Fasted cardio can also significantly help you manage your hunger and appetite more effectively, aiding in overall calorie control. For more nutrition tips, check out our Nutrition Tips for Optimal Weight Loss.

The Bottom Line

Cardio, whether fasted or not, benefits your body. While nutrition is key for optimal weight loss, cardio assists in reaching weight loss goals. Fasted cardio, with inconclusive metabolic effects research, may suit your lifestyle or preferences. If you're generally healthy, feel free to try it.

Frequently Asked Questions

• Can fasted cardio lead to more weight loss? While increasing exercise can help with weight loss, scientific research does not strongly support the theory that you can lose more weight by performing cardio on an empty stomach. Fasted cardio may result in shorter workouts or overcompensating with caloric intake at other times of the day.
• How long should you perform fasted cardio? Studies suggest that it's more difficult to do a longer cardio workout in a fasted state. If you choose to work out on an empty stomach, a 30- to 45-minute session is reasonable. You may need to work up to this length if you are beginning a new exercise regimen.
• Would 20 minutes be enough for effective fasted cardio? Doing 20 minutes of fasted cardio will certainly provide the benefits of exercise. Whether you gain additional benefit from working out because you have fasted beforehand is unclear. However, any amount of activity will lead to increased fitness, whether you have fasted or not.

Weight loss is a journey, not a sprint. Stay patient, consistent, and focused on your health. Start your journey confidently with the right guidance. Book your FREE consultation now for a healthier, happier you!Weight loss is a journey, not a sprint. Stay patient, consistent, and focused on your health. Start your journey confidently with the right guidance.? Book your FREE consultation now for a healthier, happier you!