It's not planks or sit-ups — the starburst plank is torture on your abs, obliques and shoulders (so I tried it, and here's my verdict)

The starburst side plank variation strengthens the shoulders, abs and obliques. Here's why we love it at Tom's Guide.
Yahoo

I ditched planks for zombie sit-ups for a week — here's what happened to my core

When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: Getty Images Bored of planks and crunches? Why not try mixing things up with a killer ab ...

If You Can Do This Many Sit-Ups After 55, Your Core Beats Most People Your Age

Find out how many sit-ups after 55 signal a strong, healthy core and use this 60-second test to track your strength over time.
Women's Health

This is how many sit-ups you should do every day for real results

The classic sit-up is a workout staple. Whether you've become all too familiar with the movement in your weekend HIIT class or eked out those last few reps while following a home workout video, you've ...