Classic cardio, or "going for a run", is often recommended for fat loss. This article addresses why this recommendation does not really bring success. And why interval training brings more success.
Aerobic training (also known as cardio) is sustained movement of larger muscle groups at submaximal speeds that primarily engages the aerobic energy system. Aerobic literally means "oxygen dependent or oxygen consuming" and refers to the dependence of energy metabolism on oxygen during the performance of aerobic activity. These low- or moderate-intensity activities can be done without a break for an extended period of time. An example would be long-distance running.
Cardio is still treated by many media and doctors as the health and fitness training of all. It is said to have a positive effect on the cardiovascular system and to be the most effective way to burn fat. When you look at people who stand on the treadmills in the gym or go for a run in the park, you have doubts about body fat loss. More on that later. It should also be said that without the right diet, no type of training can achieve a body fat-reducing effect. The health promotion argument is also only partially tenable. After a marathon, for example, it takes runners up to 72 hours to return their heart rate to resting heart rate and even up to a month for inflammatory markers to return to baseline levels. Muscular problems or joint pain are also common (examples: runner's knee, shin splins), since the muscular stability for a straight posture is often not available or decreases over the course of the load, which means that individual structures can be overloaded. Especially in combination with being overweight, very high forces act on the passive structures over a long period of time. With every step when jogging, around 5-6 times your body weight acts on the knee joint.
I am a fan of cardio in terms of cardiovascular training and also as a means of fat loss. But only in the form of interval training. And then only as a further training tool. Not as a basis for training. This should be the creation of muscular balance and increase in muscular maximum strength, which is the basis for all other types of strength.
The difference between the so-called steady-state endurance training and interval training is the speed (intensity) and duration of the load. In steady-state training, this can only be so high that it enables the trainee to maintain the performance long enough and to remain in the areoben metabolism. In interval training, the high speed (90-100% of the maximum) usually limits the duration of the load to a few seconds to a minute. During exercise, the trainer is in anaerobic-lactic or anaerobic-lactic metabolism. In the breaks between intervals and after interval training, while heart rate is falling but still elevated, there is increased oxygen uptake and increased fat burning. According to studies, this is up to 9 times higher than with steady-state training. The aerobic system is trained during the breaks in anaerobic training.
Benefits of Interval Training
1. More time efficient due to a shorter duration
2. Training effect on the muscles of the lower body due to high loads during sprints
3. Aerobic + anaerobic metabolism are trained in one session
4. High fat burning through optimization of the carbohydrate metabolism and through the afterburn effect (EPOC = Excess Postexercise Oxygen Consumption)
5. Sport-specific training, since most types of sport are cyclical and the anaerobic energy system is therefore primarily the limiting energy system. More on this in my article Endurance vs. Condition
Disadvantages of Steady State Training
1. More time-consuming due to longer duration
2. From 45 minutes of exertion, the cortisol value increases disproportionately, which can lead to fat accumulation, especially in the abdominal area.
3. Loss of muscle mass and strength from training slow-twitch muscle fibers that have less potential for growth and strength development.
4. Preservation of body fat, especially in the leg area, as an energy source for the long-lasting load.
5. Sport-unspecific training, since the aerobic energy system is the limiting energy system in very few sports. More on this in my article Endurance vs. Condition
If you compare a sprinter who only covers approx. 200-500m per workout with 3-5 workouts per week with a long-distance runner who runs approx. 100km per week, the visual difference becomes clear. There are no sprinters with a high percentage of body fat, sprinters always have a low percentage of body fat and strong muscles. Runners have as little muscle mass as necessary with a body fat percentage of 10-15%. They also need this, since the fat metabolism is the decisive and necessary source of energy in aerobic activity. The body does not abolish what is used. With this in mind, endurance athletes train to maintain a certain percentage of body fat. One of the most pragmatic founders of why classic cardio for fat loss is a waste of time.
For a sprinter, whose energy is provided primarily via phosphates by the anaerobic-alactacid energy system, body fat is disadvantageous because it means additional weight and friction within the fascia and thus loss of strength and does not provide him with readily available energy. It is therefore abolished - with appropriate nutrition and training volume. If your goal is to lose body fat, train like a sprinter as a complement to strength training.
In summary, three statements are crucial:
1. Anaerobic training like sprints and intervals optimize carbohydrate metabolism.
2. Aerobic training, i.e. classic cardio to reduce fat, optimizes fat metabolism.
From a physiological and hormonal point of view, the carbohydrate metabolism is decisive for a low body fat percentage.
Below are three examples of interval programs:
A program consists of 6 workouts, after which the change to an advanced program should take place. Do intervals a maximum of 2 times per week.
Before interval training, warm up for 5-10mins with accelerating (progressive), repeated (cyclical) escalation runs and stretching dynamically (not statically!) to prevent strains.
Interval training for beginners
60 second jog – 60 second walk 10 times each workout increase by 2 intervals
This interval training is ideal for beginners because it is what is called an extensive interval, which prevents overloading. However, the trainer gets a feeling for the change between higher and lower loads and can increase from training to training and thus establish a smooth transition to sprints in further interval training progressions.
Interval training for advanced users
100m hill sprint, 3min walk, repeat 10 times. Increase each workout by 2 intervals.
Interval training on the Air Assault Bike
20sec full throttle, 120sec easy, repeat 6 times. Complete.
For more information on integrating the Air Assault Bike into training , click here
Bottom line: Exercise is good for your health. Running is better than sitting. But here, too, the dose, ie frequency and volume, makes the poison. From an evolutionary point of view, more intensive and shorter loads reflect the demands on our body. You don't run 10+km from a saber-toothed tiger. You ran fast or you fought.
Our bodies are still designed for this type of stress.
In addition to strength training, short intervals are ideal for reducing body fat and increasing health and physical fitness.
Classic cardio for fat loss takes far too much time with far too little progress and success.
Good luck with interval training for fat loss!
Picture: Outstanding 6 week transformation of MMA fighter Mert Özyildirim who reduced his body fat percentage by over 12% in 6 weeks. In addition to 4 units of strength training, he also completed 6 units of MMA training and one unit of modified strongman training per week. All units were interval based. Classic cardio for fat loss was not part of his training.