Pain in ball of foot

For the past 3 months I have been experiencing pain at the ball of my feet, esp. in the right foot (on the soles). The pain seems very localized about 2 inches below the base between the big and second toe. The pain is worse after I walk or do exercise and seems to radiate out. It’s a burning type of pain. Even when walking on carpet can produce some painful sensations 2″ below the base of between the big and second toe.My background: I am a 35 year old male, not overweight. I excersize a lot esp. with the Stairmaster and leg press for the past 5 years, but have not had any pain until 3 months ago. I saw my podiastrist, she indicated that I need orthopedics and recommended some inserts for me. I asked her if I should stop excersizing, she said no. I’ve been wearing inserts now for about a week without much success. I really question if inserts are the answer. Have you encountered this problem before? What I could do to help myself?
Thank you.