Results: The anteroposterior (AP) thicknesses of all abdominal muscles, had statistically significant differences between the two groups of runners, as the rectus abdominis muscle (RA) (P < 0.001). Internal and external Oblique muscles (IO and EO) were thicker in the sprinters group; and in contrast, the transversus abdominis muscle (TA) owned more thickness among the distance runners (P < 0.05).
Since I would imagine that the sprinters were probably 10-30 pounds heavier than the distance runners, and certainly more muscular overall, it doesn’t surprise me that sprinters would have thicker muscles, even in the abs. But the distance runners having thicker transverse abdominis muscles is interesting.