20 Minutes of This is Better than an Hour of Walking

The Afterburn Effect: Enhancing Fat Loss and Fitness

The longstanding belief in the fitness world has been that prolonged, low to moderate-intensity exercise is the key to burning calories and achieving an ideal body composition. This perspective, however, is being challenged by an overwhelming body of research. A groundbreaking 2011 report in the Journal of Obesity indicates a paradigm shift, underscoring the greater effectiveness of high-intensity interval training (HIIT) over traditional aerobic workouts in reducing body fat, particularly in the abdominal and subcutaneous regions.

The Metabolic Edge of High-Intensity Exercise

During conventional aerobic activities, muscle cells primarily utilize glucose for energy. Contrastingly, the recovery phase following high-intensity workouts sees a significant metabolic shift: the body primarily uses fatty acids in addition to glucose for energy. This shift is not just a small detail but a fundamental change in how the body processes energy, leading to the dual benefit of increased fat burning and muscle building. Since muscle tissue burns more calories than fat tissue even at rest, this approach can significantly boost the body’s resting metabolic rate, aiding in more effective long-term weight management and improved body composition.

High-Intensity Interval Training as a Catalyst for EPOC

The secret to unlocking the afterburn effect lies in the intensity of the workout. High-intensity exercise pushes the body to its limits, necessitating an extensive recovery process that continues to burn calories well after training. This prolonged state of increased metabolic activity following intense physical exertion is called Excess Post-Exercise Oxygen Consumption (EPOC).

Implementing High-Intensity Workouts Effectively

Tailoring the intensity of workouts to your fitness levels is essential. This personalized approach ensures that you can reap the benefits of the afterburn effect without the risk of injury, enabling a sustainable and safe fitness journey.

1. Interval-Based Cardio Training: This strategy involves short bursts of intense exercise alternated with periods of rest or low-intensity activity. Examples include sprint intervals, high-intensity cycling, and interval rowing.

2. Strength and Resistance Training: Circuit-style training with weights or resistance exercises increases post-exercise calorie burn. This technique can encompass routines with squats, deadlifts, and bench presses, performed in succession with minimal rest between sets.

3. High-Intensity Sports: Sports that involve spontaneous high-intensity movements, such as basketball, tennis, soccer, and dance, can naturally induce a state conducive to EPOC.

Continuous Assessment and Modification of Workouts

Assessing and adjusting workout routines regularly is crucial to maximizing the afterburn effect. This intervention includes altering the types and intensity of exercises, tracking the body’s responses, and ensuring that the training remains challenging yet safe.

The Role of Professional Fitness Guidance

The guidance of fitness professionals is invaluable, particularly for those new to high-intensity workouts. They can provide expert advice on structuring plans and routines effectively, ensuring exercises are performed correctly and safely, and tailoring them to meet individual fitness goals.

Understanding Excess Post-Exercise Oxygen Consumption

Biochemical and Physiological Responses Post-Exercise

Following intense physical activity, the body undergoes a series of intricate biochemical and physiological adjustments. These include replenishing oxygen in muscle cells, neutralizing lactic acid build-up, and restoring ATP and muscle glycogen levels. Changes also involve re-establishing normal body temperature, heart rate, and breathing rate. Each process contributes to the body’s increased energy expenditure during the EPOC phase.

Hormonal Influences on EPOC

High-intensity exercises lead to significant fluctuations in hormones such as epinephrine, norepinephrine, and cortisol. These hormones are crucial in mobilizing the body’s energy stores and are essential to the increased metabolic rate observed during EPOC.

Muscle Recovery in EPOC

Muscle recovery is a critical aspect of EPOC. Repairing and rebuilding muscle fibers post-exercise requires additional energy expenditure, contributing significantly to the increased calorie burn associated with EPOC.

One study published in the Journal of Exercise Science showed that the afterburn effect is associated with an elevation in metabolism due to the thermic effect of activity, regardless of your current fitness level — and some experts believe that this can cause around a 10 percent increase in calorie expenditure for the day following just 20 minutes of high-intensity exercise.

In other words, if you’re an active woman who typically burns 2,000 calories daily, implementing HIIT might boost you to burning 2,200!

Practical Application of High-Intensity Workouts

Developing a Personalized HIIT Routine

Creating an effective HIIT routine involves selecting exercises that push the heart rate to approximately 80-95% of its maximum capacity for short intervals, followed by rest or lower-intensity periods. Here are some examples, starting with the easiest for those new to exercise:

Beginner Intervals:

Walk for 90 seconds, then power walk (walk fast and swing your arms) for 30 seconds. Slow down and recover for 90 seconds, then do another 30-second burst.

At first, you may only be able to do 2 or 3 bursts during the 20-minute session. As you become fit, add more bursts until you get up to 8 during the 20-minute workout.

Intermediate Intervals:

Power walk for 90 seconds, jog for 30 seconds, and repeat.

Advanced Intervals:

Jog for 90 seconds, run as fast as you can for 30 seconds and repeat.

You can do interval training with biking, a treadmill, an elliptical machine, swimming—just about anything. The good news is that you only need to do it for 20 minutes.

Do interval training every other day so your body has time to recover. You can download interval timers on your phone to track bursts.

*A word of caution: Interval training is for people who have been doing aerobic exercise for some time and are proficient at it. If you have heart problems or other health issues, you should not try interval training without your doctor’s consent.

Incorporating Strength Training for Enhanced EPOC

You can combine nonstop weightlifting and interval training. Do 90 seconds of weightlifting followed by a 30-second burst of more intense exercise like pushups, jumping jacks, burpees, or running in place. This technique fits both weightlifting and interval training into a 20-minute workout.

Effective strength training for maximizing EPOC should focus on compound movements that target multiple muscle groups. These exercises should challenge the muscles to the point of necessitating recovery and adaptation, thereby contributing to a heightened afterburn effect. See Appendix A, Part Seven in the 7 Systems Plan book, for more information.

Leveraging Recreational Activities for High-Intensity Exercise

Engaging in recreational activities that naturally involve high-intensity elements can provide enjoyable ways to achieve the benefits of EPOC. This lifestyle may include playing team sports, engaging in competitive games, or participating in dynamic group fitness classes.


The afterburn effect represents a significant advancement in exercise science. This approach, emphasizing shorter but more intense exercise sessions, challenges longstanding exercise principles and is supported by recent scientific research.

By effectively implementing high-intensity workouts, you can achieve more efficient fat loss, improve metabolic health, and enhance overall body composition. This approach should be implemented slowly with a balanced plan tailored to individual fitness levels to ensure long-term health and fitness benefits.

For your health

Dr. Pat

Video of the Week

Recipe of the Week

Teresa’s 7 Systems Kitchen

There is no recipe this week since Dr. Pat encourages fasting before exercise.

For even more benefits, use NutriDyn’s Performance Drink for energy and quick muscle repair & recovery after a workout.

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Dr. Pat Luse

I'm the president and CEO of one of the largest multi-disciplinary clinics in the Midwest. As one of the most highly trained health coaches in America today, I am uniquely qualified to help individuals have amazing health transformations and I can't wait to help you!


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