The exhausted football player was having trouble breathing fresh air, on the sideline he put on a mask to increase his what?\nOptions:\n- breathing\n- energy\n- think more clearly\n- oxygen intake\n- feeling refreshed
Let's think step by step.
oxygen intake
A mask helps in oxygen intake.

Oxygen intake is important for the survival of any human being.

Football player is a human being.

.

Thus, the answer is oxygen intake