Find out exactly how long to hold a plank after 50 to test your core strength, improve stability, and spot where you need ...
The starburst side plank variation strengthens the shoulders, abs and obliques. Here's why we love it at Tom's Guide.
When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: YouTube/E3 Rehab Having seen my colleague go for the two-minute Copenhagen plank ...