Also means
to reinforce
Usage Note
Fortalecer is an irregular -cer verb: the yo form is fortalezco. It is used for strengthening institutions, relationships, economies, and muscles — fortalecer la democracia, fortalecer los músculos. The related adjective is fuerte and the noun is fortaleza ('strength, fortress'). Do not confuse with reforzar ('to reinforce structurally').
Examples
"El ejercicio ayuda a fortalecer los músculos."
Natural Translation
Exercise helps to strengthen the muscles.

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