Answer:
False. During physical exercise the oxygen concentration in the blood remains the same, with regard to rest.
Step-by-step explanation:
In a healthy person, the concentration of oxygen —also called O₂ saturation— in arterial blood is in the order of 97 and 100%, both at rest and during exercise.
The concentration of oxygen in blood is a parameter that depends on proper respiratory function, and varies according to whether the blood is arterial or venous, where this percentage is lower.
The O₂ saturation in arterial blood allows to know the amount of oxygen that reaches the tissues and it is not a parameter that is modified with the exercise, although the respiratory and cardiac frequencies increase.