Ask the Coach” is the column in which Wolfgang Unsöld answers your questions. The book of the same name was published by Riva Verlag and Available right here on Amazon.
Question: Hello Mr. Unsöld, I was at your presentation at the FT Summit yesterday and was really impressed, I was very impressed. Unfortunately, a question only occurred to me afterwards, namely the topic of calorie consumption in interval training for bodybuilding. If you have the goal of maintaining muscle mass as much as possible, and especially in a calorie deficit, that is always the sticking point. Opinions are therefore divided as to whether you should work with low-intensity cardio or high-intensity interval training to burn fat apart from the calorie deficit. The latter consumes significantly more calories, but it also burns muscle mass, which you want to preserve as much as possible. How do you feel about that? Trina T
WU: I am glad that you enjoyed the lecture. And that's a very good question. First, compare the skin benefits of these two forms of cardio in relation to body fat loss.
The benefits of low-intensity cardio
– Less fatigue of muscles and nervous system with the same load duration and thus less effect on strength training and potential muscle loss
– Reduced risk of injury while using the same form of exercise
The Benefits of High Intensity Interval Training
– Greater time efficiency, which means a higher training effect with less time expenditure
– Higher afterburn effect
– Higher energy deficit, especially in the anaerobic lactic energy system
From my point of view, the decisive advantage and at the same time the biggest mistake in this context is the time efficiency of high-intensity interval training. 5 intervals of a 40-second sprint and a 4-minute break consume many times more energy during and after training than 25 minutes of low-intensity cardio. Although at this interval the duration of the load is only 200s or 2 minutes and 20 seconds in total. Which leads directly to the biggest mistake in interval training design, which I go into in great detail in the YPSI Interval Training Program Design & Periodization Seminar. Here is a quick comparison of two interval training options to explain this error:
5 intervals of 40 seconds sprint and 4 minutes rest
Total duration: almost 24 minutes
Subjective level of fatigue: moderate to high
18 intervals of 40 seconds sprint and 40 seconds rest
Total duration: 24 minutes
Subjective level of fatigue: Very high
The big difference between the two variants is the level of fatigue. Which has a very strong effect on the power output of the intervals. The difference between the first and last interval with option 1 will be many times smaller than the difference between the first and last interval with option 2. This means that the average power output is many times lower with option 2, measured in m/s for sprints. s or meters covered in the allocated time or with AirBike/WattBike in the form of average and peak performance in watts.
However, average power output is a key factor in body fat loss. A high-level sprinter who runs about 1 km per week at an average speed of 9-11 m/s has a much lower body fat percentage than a high-level marathon runner who runs about 100 km per week at an average speed of 5-6 m/s puts back. The big difference between these two cases is the high power output measured in m/s. And not, as is often assumed, the total number of kilometers per week, which would speak for the low-intensity cardio of an endurance athlete for fat loss.
Thus, high-intensity interval training is undoubtedly more effective and efficient than low-intensity cardio for increasing body fat loss. A topic I also touched on in the article Why Classic Cardio for Fat Loss Is a Waste of Time .
In terms of maintaining muscle mass, the comparison between sprinters and marathon runners is also an excellent example, as the sprinter has many times more muscle mass and the more athletic aesthetics. The reason that enables the sprinter to maintain and even build muscle mass through interval training while keeping body fat percentage low all year round is the optimal structure of the training.
The key factor in this case is avoiding excessive fatigue during interval training and possible muscle loss. The optimal design of an interval training program and the periodization of the interval training program are important for this. In order to enable a constant, high power output and a natural, progressive, constantly increasing training performance - for maximum body fat loss paired with the preservation of muscle mass.
Good luck with interval training to lose body fat without losing muscle!
Image: Sprinting on the tartan track is one of the most efficient forms of high-intensity interval training.