Thankfully, Nike are generous enough to offer free delivery and returns so if they are the wrong size you can swap them for a different one. It does depend how thick and padded your running socks are. The Nike Zoom Fly Flyknit running shoes are definitely true to size and I'd only recommend sizing up maybe half a size, if at all. My ASICS shoes have to be larger than my normal shoe size (1.5 sizes) and I've had to discard/send back Hoka, On running, and other brands due to them coming up way too small (like, 3 sizes).
I find that Nike is one of the only running shoe brands that comes up True To Size. Overall, these are extremely comfortable running shoes and you shouldn't get blisters or experience any pain from rubbing or chafing. Despite being very squidgy, they are simultaneously rigid and firm thanks to the high tech carbon fibre plate and give great support. The sole is extremely thick and I felt like I was wearing platforms. When I first put these shoes on, I was amazed at how soft, squidgy, and bouncy they felt. The Flyknit does exactly as you'd hope and moulds to your foot, giving plenty of wiggle-room for your toes. On my third run, my toes didn't go numb at all and I was able to really enjoy the comfort of these shoes. In the end, I decided it was actually my socks that were super slippery so on my next run I wore different socks and found my ankle stopped slipping and I could loosen the laces, which fixed the numb toes. I spent the rest of the run stopping and starting to readjust the laces. Unfortunately, this meant my toes went numb after 2 miles of running. On first wear, I found that my ankle was slipping out of the back of the shoe so I tied the laces extra tight. I was hoping the Flyknit technology would prevent all of that (spoiler: it did). I've suffered from numb toes with other running shoes in the past due to a cramped toe box as well as rubbing and blisters from shoes whose upper was too rigid. I chose the Flyknit design because I've had success with it in the past (on Free Runs) and I love the way it shapes, expands, and moulds to your foot. Thankfully, the Nike Zoom Fly Flyknit shoes did not disappoint. Not only am I your everyday, amateur runner, like many other runners I suffer from over-pronation, which means I have to be extra careful with my choice of running shoes.
The Nike Zoom Fly running shoes feature some of the same technology as Kipchoge's record-breaking ZoomX Vaporfly NEXT% at a fraction of the cost, making them accessible to the everyday runner like you or I. Between Eliud Kipchoge's failed 1:59 marathon attempt back in 2017 and his history-making successful attempt in 2019, Nike have released a wide range of high-end, scientific, tech-heavy running shoes which are all designed to help us run faster. Finally, a lightweight racing shoe suitable for runners who pronate