When we feel low on energy, it can be challenging to get back to our usual selves. However, there are several synonyms that we can use in place of the phrase "regain energy." One option is "rejuvenate," which means to restore or revive something's vitality. Another synonym is "revitalize," which suggests giving something new life or vigor. "Refresh" is also an appropriate alternative to "regain energy" as it represents the act of renewing or restoring something's energy. Moreover, "recharge" and "re-energize" are other words that we can use to describe the process of regaining our energy levels. Ultimately, each of these synonyms carries its distinct connotations, and the choice will depend on the context.