I don't think I'm alone in saying sit-ups aren't fun. I don't know if it's because I need to have someone or something there to make sure my feet stay put on the ground during the full movement or ...

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. Sprint interval ...

For those who live to sweat — but maybe want a chance to fully catch their breath — SIT is the new HIIT. HIIT, or high-intensity interval training, includes bursts (typically 30 seconds to a few ...

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