Breakfast has always been said to be the most important meal of the day.
But science doesn't say this,
You might think after reading this that we're going to explain how our bodies work, how our ancestors behaved, and how important fasting is for our health, but don't worry, we're not going to bore you with misconceptions and biased, poorly designed studies. We're simply going to explain why you should choose one food over another depending on the intensity and duration of your workout.
Before we begin to explain the first differences between intense and gentle training.
We would like to explain to you how the human body works and its different energy pathways when we exercise.
When we exercise, the human body is a machine for obtaining and burning energy.
Muscles decide which energy system to use based on various factors, among which the intensity of the exercise (or, in other words, the rate at which ATP, the energy currency, needs to be replenished) undoubtedly stands out. Therefore, we acknowledge that under physiological conditions, the exclusive participation of one of these systems is practically impossible; in reality, a mixed metabolism occurs in which one type of energy system will predominate over the others depending on the characteristics of the physical exercise being performed at any given time (Chicharro and Vaquero, 2006).
Next, we will explain how the body's various energy production systems interact to transfer energy during rest and physical exercise at different intensities.
PHOSPHAGEN SYSTEM (ATP-PCr)
It's the system we use to obtain energy most immediately during short-duration, very high-intensity exercises. For example:
10 to 100 meter sprint
100-meter swimming race
Any explosive activity during the first 3 to 10 seconds
According to Katch (2015), each kg of skeletal muscle stores approximately 5 mmol of ATP and 15 mmol of PCr.
For a person with 30 kg of muscle mass, this is equivalent to about 570 to 690 mmol of phosphagens.
If physical exercise activates 20 kg of muscle mass, the energy stored in these phosphagens could allow a brisk walk for 1 minute, a slow run for 20 to 30 seconds, or a sprint running or swimming at maximum speed for 6 to 8 seconds.
Therefore, in the 100-meter sprint in athletics, the amount of intramuscular phosphagens substantially influences the maximum energy production during very short periods of time.
That's why explosive athletes usually have the biggest muscles.
GLYCOLYTIC SYSTEM
Glucose allows us to obtain energy under both aerobic and anaerobic conditions; that is, it is the only substrate that the cell can use to obtain energy with or without the presence of oxygen. This process of obtaining energy through the breakdown of glucose is called glycolysis.
ANAEROBIC LACTIC GLYCOLYSIS
Anaerobic glycolysis only generates about 5% of the total energy obtained after the complete breakdown of the glucose molecule.
Examples of activities that rely heavily on the energy generated during rapid glycolysis include the final sprint at the end of a mile race, a 50- and 100-meter swimming event, and even the crucial and decisive role of energy in sports characterized by numerous sprints, such as field hockey, rugby, or soccer. The final sprint of a stage of the Tour de France is another example.
OXIDATIVE OR AEROBIC SYSTEM
This energy system has a moderate degree of energy power production and requires the presence of oxygen.
However, its ability to produce energy is unlimited since it uses blood glucose, fatty acids, and proteins as a substrate or chemical fuel.
The most characteristic efforts or activities in which this system is predominant are, for example:
middle-distance races (5000-10,000 meters), marathons, trails, triathlon, open water swimming, team sports, certain combat sports, etc.
Now that you know what types of energy systems we have in our body, let's explain why you should eat certain foods for breakfast depending on which energy system you want to prioritize during training, and thus be more efficient.
GENTLE DAY BREAKFASTS
On days when we train lightly, we always believe that going into a 2-hour workout at low intensity on an empty stomach will improve our metabolism and make us more efficient at burning fat.
I'm sorry to tell you that this isn't entirely true.
When we exercise at low intensity, our primary energy system activated is our oxidative system, mainly through the use of fatty acids. However, this doesn't mean we don't continue to activate other pathways, such as the glycolytic system or the oxidative system using carbohydrates.
It is true that science states that high carbohydrate consumption during exercise promotes the use of carbohydrates when we exercise, but this has a limit.
And the limit is having a balance.
As you know, the human body is a perfect machine, constantly undergoing osmosis to maintain stability in all physiological aspects. Therefore, if the body is fasting, without eating anything at all, for two hours of light exercise, the resulting fatigue will be much greater than if we didn't have a low but necessary intake of carbohydrates during the exercise.
And here comes the question that all the athletes who have been and continue to come to my consultation always ask me…
And what is the ideal amount to generate metabolic benefits from fats but without causing too much fatigue in this type of training?
And the answer is always the same: in light/fasted training, we should consume around 20 to 40 grams of carbohydrates per hour to avoid extreme fatigue and without harming the goal we have in this type of training, which is to be more metabolically efficient.
An example would be
2 slices of white toast
40 grams of avocado or 10 grams of extra virgin olive oil
40g of turkey or a lean, fat-free protein
We would mainly have 60% fats, 20% proteins and 20% carbohydrates.
As you can see, the amount of carbohydrates is not completely eliminated, but it is greatly reduced compared to other types of breakfast.
BREAKFASTS FOR INTENSE DAYS
On busy days our breakfast changes completely.
During exercise we will take carbohydrates in a 1:0.8 ratio, and in amounts appropriate to our level of assimilation, intensity and duration of exercise.
Regarding breakfast, we will prioritize foods rich in simple carbohydrates, reducing fats and proteins.
A clear and frequently used example during series days is:
2 to 3 slices of white toast
40 grams of jam
70 grams of fresh cheese
The idea in this type of training is to reach the maximum muscle glycogen reserves, and this is achieved by eating foods rich in simple carbohydrates hours before training.
And since we know that many athletes will want to know what quantities of food to eat according to their training after reading this guide.
Below you'll find a very clear image showing the amount of carbohydrates to consume depending on the hours leading up to intense training.
If it were light training, the amount would be reduced by half.
