With the arrival of summer and fall comes racing season. Marathons (half and full), triathlons, obstacle course races (Spartan, ToughMudder, Rugged Maniac) abound, and if you’re planning to race in one of these, you need to make sure your cardio and your legs are strong enough to get you to the finish line.

Whether in training for a specific sport or event or working out to reach a particular goal, we all want that heart-bursting-through-the-chest feeling — it means we're really pushing ourselves to the limit. Sometimes we get that feeling by sprinting or running long distances, by lifting our max at the gym, working our butts off in a group fitness class like boot camp, or by out-hustling others on the court or on the field.

In honor of the Navy SEALs and all of our military heroes, we're dedicating this month's workout to the brave men and women who have served and continue to serve our country. It's meant to prepare your lungs and muscles for the Memorial Day weekend challenge of completing the "Murph" challenge.