No, not sit-ups — try the runner's plank to strengthen your abs without hurting your lower back

The runner's plank is an alternative I use as a certified trainer when sit-ups aren't possible, and this is exactly how to do ...
Women's Health

This 85-Year-Old Woman Can Hold A 9-Minute Plank—Here's Exactly How She Trains

Although Erika Rischko set a new nine-minute plank record at the end of August, it wasn't a feat she'd set herself the goal of accomplishing. As it turns out, the 85-year-old fitness influencer from ...