Physiology A healthy 30-year-old male runs on the treadmill for 30 mins.Which of the following muscle does this person use during expiration? A Sternocleidomastoid and Diaphragm B Diaphragm and Internal intercostals C Internal intercostals and abdominal recti D Sternocleidomastoid 💡 Explanation A healthy 30-year-old male runs on the treadmill for 30 mins.Which of the following muscle does this person use during expiration? ✓ Correct Answer: C. Internal intercostals and abdominal recti