DUISBURG, Germany (AP) -- Birgit Fischer's personal doctor has stopped the 50-year-old eight-time Olympic champion's latest comeback attempt only one day before the German canoe and kayak Olympic trials.

The German federation says a routine check produced medical results that need to be further examined and that Fischer cannot be allowed to compete.

Germany's most decorated Olympian says she is feeling "fitter than in my most recent comeback in 2003."

No details of Fischer's medical condition were released, but the German team's doctor also said she could not compete.

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