During the race the concentration of sugar in the athletes blood decreases

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

Ifound this information on google “yes. they have a mouth and brain at one end and an anus at the opposite end. what characteristics distinguish an annelid from other worms? annelids have segmented bodies and a coelem which is a tube filled with fluid and contains most of the organs.“ i hope it you

If you get a map and put the countries a states all together it forms all one piece you can also tell because of the earth quakes