Enervate and energise are antonyms which means they are opposites, though increasingly enervate is mistakenly used as a synonym for energise.

Enervate means to deprive of force or strength, to destroy the vigour of, to weaken, to sap, to drain someone of energy, to make someone feel weak in a physical or mental way, to make someone feel debilitated.

• The gloomy, rainy weather seemed to enervate her system and she grew daily more weak and depressed.

• Britain’s democratic system is enervated and paralysed by parliament’s inability to make progress with Brexit.
• Spain’s spectacular goal invigorated their team’s spirits, but enervated Portugal’s playing even though before they had looked the stronger side.

Energise means to imbue with energy, to make someone feel strong in a physical or mental way, to fill with vitality.

• He felt tired and weary until he found the café and drank an energising cup of strong coffee.

• The gift of a small piece of common land energised the whole community to take part in a gardening project.

• Pilates is a great form of exercise to energise the body and make it more supple.