Quick biology lesson: the posterior chain is the term for the network of muscles that run the entire back length of our body, ...
At 85, Erika Rischko held a plank for 9 minutes live on TV. Here’s how she trains, why she loves planks, and her advice for staying fit at any age.
Planks and jumping jacks are perfectly fine workout moves. But if you combine the two together, you can actually get an even better total-body workout. Meet: the plank jack! How To Do Plank Jacks For ...