I would think this is true.
This may be caused by cellular respiration, precisely, the glycolysis stage of anaerobic respiration (because an athletes in a race would need immediate energy). Glucose breaks down at this stage to produce lactic acid, so it would probably make sense that the concentration of sugar decreases.
This is only what I think, and may not all be truth, so I suggest that you wait for a more 'advanced' response :D
<em>Answer:</em>
<u>Polymerase Chain Reaction (PCR)</u>
Explanation:
Note that Polymerases Chain Reaction (PCR) is used to amplify food DNA to test for the presence of genetically modified DNA in food products because usually DNA fragments can be isolated from highly processed goods and are sufficiently intact to be amplified by PCR.
The process used by Genetic engineers is <u>called gel electrophoresis </u>where only a small number of regulatory sequences (promoter and terminator sequences) are used to control the expression of the inserted genes.
Through an electron transport chain.
Scientists often perform experiments to check and recheck their work. They also redo these experiments to ensure correct results.