[prmph]

> mainly attenuated

> may reflect

So the study acknowledges that this is all not yet settled. The (potentially damaging) effect of excessive exercise may be stronger what the study found, or it may be neutral (i.e., not actually extending lifespan, but not damaging it either)

It remains to be seen what further studies reveal, but for now the blog is not far off in speculating a potentially damaging effect.