Proform crosswalk 225x treadmill Functions The 325X is a ProForm Crosswalk model treadmill. Crosswalk treadmills include arm levers that allow you to move your arms in sync with your legs as you workout. The 325X has a resistance option for the arms so you can increase the intensity of your upper-body workout. Features The 325X offers a pulse sensor so you can track your heart rate during the workout. Place your thumb on the sensor located on the console. Your heart rate will display in a few seconds. The console also displays the time elapsed, distance traveled and approximate calories burned.