The principle is simpler than you think: slow exercises train the economy of lipid metabolism, intensive and fast ones burn, from an absolute point of view, more calories and therefore also more fat. They are therefore two different forms of training with two different objectives.
A NEGATIVE ENERGY BALANCE, NO WEIGHT LOSS
Let’s start with weight loss. To lose weight you need to work on the energy balance. What you put into your body must also come out, otherwise, the fat pads will accumulate. Unused calories are stored by the body in the form of fat. The energy balance is therefore the decisive criterion for weight loss. Only when the difference between the intake (calories consumed with the diet) and expenditure (calories burned) is negative, that is, the energy consumption is greater than the energy intake, does one lose weight.
Energy expenditure can be increased with greater effort, while the intake can be reduced with an intelligently dosed diet. If you want to contribute to weight loss through sport, there are two possible approaches. You can try to burn as many calories as possible in a short time, that is, make the most of the effort to burn the maximum of calories. Or you can increase the duration of the movement by choosing a rhythm that allows you to resist as long as possible. This is feasible only with a medium intensity, which does not force you to mainly use carbohydrates for energy supply, but also burns fat by means of oxygen.
In percentage terms, the lower the intensity of physical exertion, the greater the amount of fat burned. For this reason, this intensity level is often referred to as the “lipolytic zone” or fat burning zone. However, this only applies in percentage terms, because the absolute amount of fat burned in the lipolytic area is still lower than in intensive exercise, due to the low total energy expenditure (see graph).
LIPID METABOLISM FOR A GREATER ECONOMY
The training method in the low-intensity lipolytic zone also has another particular relevance in endurance sports. The combustion of carbohydrates (= combustion of glycogen, therefore of sugar) provides about twice as much energy as that of fats, but fats burn much longer and are practically always present in the body. The glycogen reserves are instead sufficient for a load of about 90 minutes.
Training regularly in the moderate range of fat metabolism therefore forms the fundamental foundation upon which to build all other workouts. Also, a less intensive workout takes less time to regenerate and can be repeated more often.
By accessing lipid metabolism, our body improves the cheaper of the two main metabolisms in endurance sports. As a result, glycogen reserves, which are only available in limited quantities, can be saved. With lipid metabolism, you can run for hours or days, while with glycogen metabolism in the best of cases one or two hours if you do not replenish new carbohydrates. The more trained your fat metabolism is, the more it helps you from the start to preserve carbohydrates and thus maintain the desired speed until the end. You are also less likely to suddenly suffer from hunger.
WHAT ARE THE ADVANTAGES OF METABOLIC TRAINING?
Training fat metabolism makes sense not only for runners (and marathoners) but also for all endurance athletes who have to endure long efforts. Cyclists and triathletes also specially train fat metabolism when preparing for the season. The longer the race load, the more important the lipid metabolism is. Training improves endurance in the long run: the body produces more blood to transport oxygen more efficiently and the number of energy-producing plants in the muscles (mitochondria) increases, allowing the cells to produce even more energy. Thanks to the body’s adaptation, the body can more easily withstand the training loads. Finally, in addition to muscles and blood, cartilage, tendons, and ligaments also develop, so you can better cope with training and protect yourself from problems due to overload.
WHEN DOES METABOLIC TRAINING START?
Lipid metabolism is exploited at almost all intensities, but only when the duration of the effort is long and the intensity low can we speak of classic lipid metabolism training. In running, long workouts, from 60 to 180 minutes (depending on your goals), should be done once a week. Combined with other long-lasting extensive racing, they create the necessary foundation. Extensive workouts are complemented by intensive workouts in a 1: 3 ratio, in which three extensive workouts are followed by one intensive workout.
To be successful in sport, it is necessary to invest all year in the training of lipid metabolism. The good thing is that these workouts are not very intense and only become challenging due to the long duration. To break the monotony, we recommend performing them with companions or changing the route from time to time.
PERCENTAGE SHARE OF PROCESSES THAT SUPPLY ENERGY BASED ON DIFFERENT LOADS
LIPID METABOLISM: THE “DIESEL ENGINE” OF OUR BODY
The two metabolic systems, namely the lipid and the carbohydrate, are always both involved in the endurance effort, but not to the same extent. The metabolism of carbohydrates is mainly used during intensive physical exercise, while, with the increase in the duration of the training and the decrease in heart rate, the metabolism of fats ensures the highest percentage of energy supply. Training in the ideal lipid zone does not mean burning the maximum number of calories (intensive training burns more calories in total than quiet training), but rather improving the economy of lipid metabolism at low intensities so that this metabolism can participate in the supply of energy even in case of more intense loads.