Thanks, rwcarson11, for the reply. The article was helpful.

If you have ever seen an asthma or emphysema attack, you know that these accessory muscles work on exhalation. I do not know if the chest tightness I feel with the active exercises is related to intercostal contraction or something else, but it is real.

The key is the question about what is the best, most efficient physical origin of the extra, necessary support/volume with active exercises. I think I am having difficulty differentiating “support” and unnecessary tension.

Thanks again for your reply.