TUO PERSONAL TRAINER A CAT
Doing fasting cardio activities has always been considered the winning weight-loss weapon.
This theory derives from the fact that by training after the long night fast, with the reserves of hepatic glycogen at a very low level, we will use more fatty acids in training, which would automatically result in more weight loss.
The only thing that is not considered, however, is that weight loss is not directly linked to fatty acids, this is because using fatty acids for energy purposes does not necessarily mean losing weight over time, as the body has compensatory processes during the hours following the training.
In other words:
If you have consumed more fat, you will have a metabolic shift towards higher sugar consumption or vice versa with the consequence that at the end of the day, even if in the morning we had consumed more fatty acids with fasting, on a caloric level we will not have a greater loss of weight given the conversation that the body will carry out.
Just about this subject, in 2014 some researchers published a study that examined 20 female subjects: a caloric deficit of 500 calories per week and a protocol was created for all participants. 60 minutes of cardio three times a week, to get you started with what would then be the actual study.
Subsequently two groups were formed each of 10 subjects each: one who performed pre-breakfast fasting cardio and one with a full stomach.
The study concluded by stating that with the same calorie deficit and daily energy expenditure there was no significant difference.
Therefore my conclusion is to do the cardio when you prefer and how you are better but do not expect that doing so at a specific time of the day really changes something if not your motivation.