Many people have said it: You can’t do too much upper-chest work. It’s an area of the body that can almost always be improved. One way to improve it is through push-ups. But not just any push-ups: flexed trunk push-ups. Sports researchers at Inje University in South Korea investigated the difference in muscle activation between standard push-ups and flexed trunk push-ups, when the subject keeps the lower body at a 30-degree angle.
Instead of a flat back, the glutes are pushed toward the ceiling in a modest pike position. By measuring the electrical activity in the muscle groups, the scientists found that this variation of push-up elicited far more response in the muscle fibers of the upper chest and serratus anterior than a traditional push-up. Conversely, the traditional push-up created more stimulation in the lower pecs than the flexed-trunk push-up.