__________ is the most common type of stretching.
A thing I have never had the time to look more closely into. But I find both variants: What I love most is ... or What I love the most is ... I think the more common form is 'the most', and I ... adverbs - Which is more common - 'the most' or 'most'? - English ... The Scranton Times-Tribune: The 10 most common stretches and what they’re good for
Blood Flow And Stretching