‘The plank jack is a similar exercise to the press up and front plank, in that it requires loading and control of the core in a lengthened position and involves using the arms and shoulders to ...

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 ...