Answer:
A. amount of lactic acid
Explanation:
Skipping the heat before performing an intense physical training will create an oxygen flow in the body, which will increase the amount of lactic acid, which can cause muscle fatigue and even cramps.
In the presence of oxygen and little need for this macronutrient, the body would use fat to resynthesize ATP, since fat generates more ATP than glucose, and its source is practically unlimited in our body, not taking it to risk suffer from the misuse of this substrate. On the other hand, in the need for high speed ATP resynthesis, the body will opt for glucose or hepatic and muscular glycogen; as in strenuous and very intense exercises. This would also occur in the absence of oxygen during the transformation process to generate energy, called the glycolysis cycle.
This cycle would be able to generate enough energy for ATP resynthesis, but it would have an undesirable effect, the production of lactic acid (a "toxic" by-product generated during the ATP resynthesis cycle), which would cause the exercise to be interrupted within minutes. then by the installation of muscle fatigue of the active muscles (exercised muscles).
