Why is it my friend's chest burns when he begins running and then after 20 minutes it goes away?

Question

My friend, who is 46, said that the past several weeks his chest/lungs? burn when he begins running, but if he continues, the burning goes away after 2 or 3 miles. He starts out slow and runs easy for about an hour with a heartrate under 140. If he were racing his heartrate would be 165-185. Any ideas?

Answer 1

There are several things that can cause chest burning when running so it is imperitive that he see a doctor to be sure that all is well. Some things that can cause this is:
undiagnosed asthma
acid reflux
undiagnosed heart condition
lung condition
cold air (if weather is cold)

It could also be a lack of oxygen if not breathing properly or, if new to running, his heart may not be conditioned yet. However, it would be safest if he made his doctor aware of this problem and got checked out medically.