Need to do a lot of resource collecting and running around in Last Day on Earth? Luckily, there’s a way to restore energy for free, and technically instantly.
In Last Day on Earth, players have 100 energy total. Running to locations typically cost 10-40 energy total. Energy can replenish itself, at a rate of 1 energy every 5 minutes.

How to refill energy in Last Day on Earth
Without using mods or hacks, the only way to restore energy for free right now is by watching an advertisement in game. Last Day on Earth provides you an option if you have no energy, which is to watch a 15-30 second long video advertisement which will allow you to restore 15 energy. There is no limit to how many times you can do this, There is in fact a limit to how many ads you can watch, so use them wisely.
To watch an ad and restore energy in Last Day on Earth, open your map and select a location that you want to travel to. You will need to make sure you don’t have enough energy to run to the location. When the notification pops up saying you don’t have enough energy, choose watch ad. Once it’s over, 15 energy will have been replenished!
Future Updates
Hopefully in future updates, the developers could implement features such as sleeping in base, which would help restore energy. This would lower their ad revenue and possibly other income from in-app purchases, but this would be a great feature for players.