Stress echo ( with Medications) Cardiac markers IgE levels Allergy profile Pulmonary function tests

Kindly consult a cardiologist.

The chest wall expansion is a muscular activity. The diaphragm is the muscles which lies under the lungs which is responsible partly for the expansion of chest along with the muscles inbetween the ribs. So in case of tiredness and early fatigue of muscles, the muscles tend to experience spasms. You need to consume lots of water and stay hydrated and also have a good electrolyte diet. Have bananas and fruits during your workout phase. They replenish most of the electrolytes required by the body. In summer we tend to lose more electrolytes than in any other season.

Could be muscular But still get an ECG for safer side Decrease your running distance and then assess