I have noticed the same problem with Vibrams being of poor manufacturing quality.
When I first started to wear them I would get 300 miles out if a pair, now it is barely 100. I read online that the quality drop was due to their shifting production from China to Vietnam.
According to my 620 I can do a mile in under a minute.....
Many runners go the opposite way and over dress. Saw a runner this evening in a jacket and leggings in the middle of August.
Me I try and wear as little as possible, just a vest and shorts. It's easier to run fast if you are cool.
I do run on my forefoot. In Vibrams. But they cost £105 and only last 150 miles.
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