The past tense of ‘sweat’ is ‘sweated’.
‘Sweat’ is a regular verb, which means that we form the past tense by adding ‘-ed’ to the base form. So, you would say, ‘I sweated during the workout’ to indicate that the action of sweating happened in the past. This follows the general rule for forming the past tense in English for regular verbs, making it straightforward to remember.