In the above video, Men’s Health Fitness Director BJ Gaddour, demonstrates the plank trench crawl, a plank variation that forces your core to stabilise - rapidly and repeatedly - as you shift your body weight back and forth like a soldier crawling through the trenches.
Once you’ve got the form down, plug the plank trench crawl into a circuit as a core exercise, or do a couple of sets of as many quality trench crawls as you can in one to two minutes at the beginning or end of your workout.