Beth Skwarecki is Lifehacker’s Senior Health Editor, and holds certifications as a personal trainer and weightlifting coach. She has been writing about health for over 10 years. Arm day can be one of ...

A lot of people aim to lose fat, however, in the process, they also lose muscle. Therefore, it is important that you focus on building muscle and shedding fat. For this, you'll have to follow an ...

‘Everyone online has a best exercise list, which makes it virtually impossible to know which ones truly work,’ says Sarah Mackay, best known as liftwsarah on social media. ‘You deserve to know which ...