fortalecer
verbCEFR B1
What does “fortalecer” mean in English?
1.to strengthen
to strengthen (build physical strength in a muscle or body area) — fortalecer los músculos, fortalecer la espalda
2.to strengthen
to strengthen (make more robust: a relationship, an institution) — fortalecer los lazos, fortalecer la economía
Example sentences
Estos ejercicios están diseñados para fortalecer los músculos estabilizadores que protegen las articulaciones y previenen lesiones a largo plazo.
These exercises are designed to strengthen the stabiliser muscles that protect the joints and prevent injuries in the long term.
Cuando empezó la rehabilitación, el fisioterapeuta le dijo que era esencial que fortaleciera la zona lumbar antes de volver al deporte.
When he started rehabilitation, the physiotherapist told him it was essential that he strengthen the lumbar area before returning to sport.
How to use it
Fortalecer means 'to strengthen' and belongs to the -ecer conjugation group (irregular yo: fortalezco). It takes a direct object (fortalecer los músculos, fortalecer la espalda). The reflexive fortalecerse means 'to get stronger'. Used in both fitness and metaphorical contexts (fortalecer una relación), but body-and-fitness sense dominates at B1.
Common mistake
The key irregularity is the yo form: yo fortalezco (not fortaleso). This is the standard -ecer/-acer/-ocer pattern (conozco, ofrezco). Do not confuse fortalecer (build strength) with tonificar (build definition/tone) — these are distinct fitness concepts.