I should probably start bookmarking this stuff. To be clear, the connection to exercise resistance/intolerance is my own speculation. Most of the actual research so far is focused on the relationship between abnormal interoception and aspects of mental illness. A lot of this is also pretty preliminary; as far as I can tell, there's not yet much consensus on even a rigorous definition of which sensory functions qualify as "interoceptive", let alone validation of methods to measure it. That being said, interesting articles include:
Alexithymia, not autism, is associated with impaired interoception [1]
“Lacking warmth”: Alexithymia trait is related to warm-specific thermal somatosensory processing [2]
Alexithymia: a general deficit of interoception [3]
Alexithymia Is Associated With a Multidomain, Multidimensional Failure of Interoception: Evidence From Novel Tests [4]
Alexithymia, not autism, is associated with impaired interoception [1]
“Lacking warmth”: Alexithymia trait is related to warm-specific thermal somatosensory processing [2]
Alexithymia: a general deficit of interoception [3]
Alexithymia Is Associated With a Multidomain, Multidimensional Failure of Interoception: Evidence From Novel Tests [4]
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4962768/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5595273/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5098957/
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5824617/