Your legs will appreciate the blessed location of Praia das Moitas, also known as Praia da Rata, next to Monte do Estoril station. It is small and rocky, so extra caution is needed to avoid accidents. Does your company prefer calm waters? Direct them to the Alberto Romano ocean pool, just around the corner (heading from Lisbon to Cascais). It operates from 08:00 to 18:00 and has free access.
How to get there: If you chose the train, get off at Monte Estoril station and walk down to the seafront promenade. Turn right towards Cascais, and Rata is the first beach you will encounter.