Have you seen your abdominal muscles lately? Maybe they’re hiding behind the holiday goodies we ate, but they are there, I promise.
Abs are part of your core and, when weak, contribute to slouching. NO SLOUCHING in the booth, guys!
Planks are one of the best core strengthening movements, and are done with no equipment.
Here’s a beginner’s guide:https://www.wikihow.com/How-Long-to-Hold-a-Plank-As-a…