It's perfectly normal to be lazy sometimes. We all have those moments where our energy is fully drained. Being unproductive is mostly caused by lack of interest, decreased level of motivation, or excessive impulses or distractions. These increase the release of dopamine, a neutrotransmitter responsible for reward and pleasure. 

Before we do anything to stop our lazyness, we must first identify the cause, identify what's holding you back. Figure out what's making you lazy. Put future self before present self. Focus on the goal that you want to achieve.