Why would my left heel hurt after i exercise? doesn't hurt till15-30mins after i have left the gym. just started about a week ago. no other symptoms.

Plantar fasciitis: It sounds like you may have developed plantar fasciitis and may have a bone spur with it. Best to be examined by a podiatrist.

Plantar fasciitis: Plantar fasciitis, or an arch ligament strain is a very common reason for pain in the bottom of the heel. There can sometimes be a bursitis under the heel as well. Other causes of heel pain can be tarsal tunnel syndrome, arthritis, a stress fracture, referred nerve pain among others. Talk to a podiatrist to help sort this out. Stretch consistently and make sure your shoes are in good shape.