A new University of Michigan study finds giving birth to be harder on your body than running a marathon—so, we ask, where are our medals, then? Ahem. Hey Mama, if you're thinking about adding 'running a marathon' to your bucket list, we know you can do it. According to new research, giving birth is way harder than logging 26.2 consecutive miles. That's right: your body was made to not only birth out a new life, but it's harder than running for around four hours.