Lindsey Ellefson is Lifehacker’s Features Editor. She currently covers study and productivity hacks, as well as household and digital decluttering, and oversees the freelancers on the sex and ...

Sweat drips down my face and lower back. My muscles are shaky; my breathing is shallow and unsteady. The only thing getting me through this intense workout? Lizzo's "Good as Hell" blasting through my ...