Group fitness has entered its strength era.

Crunches are a familiar movement that you can easily do from the comfort of your own home or in a gym setting. This quick, 15-minute (or less!) series can be completed with minimal to no equipment.

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: Shutterstock ...

They’re often lumped together as “ab exercises,” but crunches and situps aren’t the same thing — and choosing the right one can impact your results (and your spine). So, if your goal is stronger abs, ...

If you’re a little hazy on the difference between sit-ups vs. crunches, you’re not alone. They both strengthen your core, but the details on how they differ and the benefits of each can be confusing. ...