Watching babies crawl, we will find that they can keep their backs flat without instructions, and actually move on all fours. Now we do have bear crawling, which can not only exercise the muscle strength of limbs, but also strengthen the stability of trunk, improve the flexibility of limbs and train the coordination of the whole body.
Usually the bear crawl will be arranged in the warm-up stage, which can be used as a wake-up call when there is no load. In the main training part, you can push and pull bars on the ground, or tie a sled to increase the training intensity.