Anyone looking for an example of poor health science conflating correlation and causation should check out this laugher in the Times:
Why a Brisk Walk Is Better
Walking, fast or slow, is wonderful exercise. But now a first-of-its-kind study shows that to get the most health benefits from walking, many of us need to pick up the pace.
Evetually we learn that people who tend to walk slower while exercising are also more likely to die sooner. As to distinguishing cause and effect, both the study author and the Times reporter (Gretchen Reynolds, who surely knows better) eventually identify the screamingly obvious flaw in the headlined "logic". But the headline and lead were catchy, so here we are.