Sitting around doesn't help. You gotta move. 

As tips blog Barking Up the Wrong Tree explains, passive activities—meaning activities that don’t require much input from you, like watching TV—don’t do much to help your energy levels. Feeling low-energy doesn’t always mean that you need a rest. Sometimes it just means you need to get up off your butt and do something:

Counterintuitive, I know. But when you’re tired tonight but want to not be tired tomorrow, do active things like exercise or spend time with friends.

Don’t do a marathon session in front of the TV or mindlessly surf the web.

If you’re sleepy, or generally exhausted after having already spent a ton of energy throughout the day, that’s one thing. You might need a rest. But if you’re weary because you’ve been sitting in an office all day, or just generally bored, try exercising, going outside, or talking to some people to get your energy back.