Nike Air Zoom Pegasus 38 review and lab test

Problems from the Peg 37 have been solved!

The Nike Pegasus 38 is a plush daily trainer with a stable midsole and a peppy ride. This shoe can be your slow day shoe, your tempo shoe, and your gym shoe, it can basically do it all.  

Pieces of the Pegasus 38

Who the shoe is (not) for 

Not everyone needs a quiver of shoes, some prefer to just have one that can do everything. The Nike Air Zoom Pegasus 38 fills that role nicely thanks to some thoughtful updates from Nike. 

The Peg 38 gets a slightly wider toe box and deeper heel cup than the Pegasus 37, issues that dogged the last iteration of this shoe. If you’re looking for a comfortable trainer that has the pep for speed work and the cushion for slow days, this could be the shoe for you. 

Pegasus 38 in the lab

Don’t buy the Peg 38 if: 

  • You have a super wide foot. Nikes still tend to run a bit narrow in my opinion, and although the Peg 38 is wider than past iterations it’s still not an excessively roomy shoe.
  • You run in warm temps. The updated upper is dense and layered, and it runs a bit hot. 
  • You’re expecting this to be an ultra-lightweight race-day shoe. It’s not. Check out the Vaporfly Next% 2 if you want a true race shoe. 

Wider but still not super roomy

I have never really been comfortable in Nike shoes, they all seem too narrow in the midfoot for me. I will admit though the Pegasus 38 worked for me, it fit thanks to the updated toe box which gained a bit of room and the stretchy upper material that accommodates a wide variety of foot shapes. 

Although it did fit, I probably wouldn’t pick this shoe for long runs as it still felt a bit tight, so if you have really wide feet, you might want to consider another brand. Try the Saucony Ride 14, it feels considerably wider.

Plush comfort with pep 

Looking beyond the width of the midfoot, this shoe was surprisingly comfortable. The upper is plush and hugs your foot nicely.

The sock-like design is not restricting or hard to put on, which most sock-like struggle with. The midsole is soft enough to make your feet happy, and the Zoom Air unit adds cushioned pep under your forefoot.

Zoom Air unit on PEgasus 38

The only downside to the Pegasus 38’s comfort is it almost seems like a mix between a sneaker and a running shoe to me. The thick, layered upper is dense and feels like a heavy blanket hugging your feet, which makes me want to take these to the gym rather than out on a long run. 

Peg 38 has a peppy ride & makes you smile

The Nike React midsole is soft, but not bouncy or unstable like ZoomX. It’s also not overly soft, it doesn’t rob you of your efficiency like some super-plush recovery shoes. 

Mix the React midsole with Nike’s Zoom Air unit, and you have a stable consistent platform with nice pop off the toes. I think this is a great combo, and it really is a joy to run in. 

Air Zoom unit on Pegasus 38

I’ve been comparing this to the Vaporfly a lot in my mind, they look similar, both my test pairs were white, and they have a long pointy tail.

Pointy heel on Pegasus 38

I see the Pegasus as a nice compliment to the Vaporfly in an all-Nike lineup.

Forefoot width of Pegasus 38

What I like about the Pegasus though is it’s much more stable underfoot, at 109.5mm wide in the forefoot, and 80.7mm in the heel, it’s got more platform to balance on, which was needed coming from the Vaporfly.

Heel width of Pegasus 38

If only it were lighterweight

One downside to the Pegasus 38 is its heft. This is not a lightweight shoe.

Pegasus 38 weight

At 10.25 ounces (291g) there are a lot of lighter everyday trainers out there, the average weighs just 9.6 ounces. The shoe feels heavy, period. 

Nike needs to find a way to get this to 9 ounces for it to really be a shoe I’d lace up daily. 

Go long and far in the Pegasus 38B

Nike has built a solid shoe here though, and I think it will go 400-500 miles. The React midsole at 19.5HA on the durometer is 18% softener than average but it seems dense and controlled underfoot and I don’t see it packing out prematurely. 

Outsole thickness on Nike Pegasus 38

There’s also a lugged 3.97mm outsole that’s firm (87.5HC on the durometer - 11% firmer than average) which should wear down slowly.  

You can even hit the dirt

One thing I love about this shoe is the outsole is dotted with 2.32mm lugs, giving it great traction and the ability to hit some non-technical dirt when the wild hair catches you. 

Outsole on Nike Air Zoom Pegasus 38

For me, this is a great feature as I tend to run in the dirt on the side of the road on long efforts since the impact is a bit easier on my legs.

Pegasus 38 runs hot

One major con in the update of the Pegasus 38 is the upper. It’s just too thick. It feels luxurious on your feet, but it’s warm and doesn’t breathe well.

Nike Air Zoom Pegasus 38 upper

I wish Nike would re-imagine this upper and just go with a single-layer engineered mesh, drop a bunch of weight and warmth all in one swoop. 

Adequate lockdown is better than prior versions 

The lockdown on the shoe is adequate. There’s still some heel slip, but my heels slip in a lot of shoes. The key here is that Nike did fix the real problems in the heel department the Peg 37 had, but to me, they still need to go a step further. 

Over the midfoot though, the shoe performs great. The fully-gusseted tongue helps lock your foot in, and the webbing lacing pattern evenly distributes pressure across the shoe and down into the stroble board keeping your foot solidly in place. 

Laces on Pegasus 38

The thick, flat laces also are a nice touch, they keep the pressure low over the top of your foot when combined with the 5.6mm padded tongue.

Nike Air Zoom Pegasus 38 lacing system

They stay nice and tight as well, measuring 29.3N on our lace slip test, which is well above the average of 25.3N. 

Conclusion 

At $120 I think the Nike Air Zoom Pegasus 38 is a pretty hot deal! 

Overall I’m impressed with how much I liked this shoe. The midsole is stable, cushioned, and still peppy. The upper hugs your foot nicely and is cut a bit wider than in the past which was a deal-breaker for me in the Peg 37. 

The shoe does run hot, and it’s a bit on the heavy side, but it's not half bad, which is pretty good praise for a Nike product as far as I am concerned.

Complete lab-specs overview 

  Pegasus 38 Average
Whole shoe
Weight (g) 291.0 269.2
Drop (mm) 8.7 7.9
Flexibility of the shoe (N) 27.6 36.8
Flexibility of the shoe (Freezer 1 hour) (N) 36.2 51.6
Flexibility of the shoe (% of change) 31.2 56.44
Lace slip test with the knot (N) 29.3 25.2
Longitudinal flexibility (on a 0-5 scale, 0 being the stiffest) 3 2.2
Torsional flexibility (on a 0-5 scale, 0 being the stiffest) 3 2.1
 
Thickness - Tongue (mm) 5.6 5.4
Width Upper - Forefoot (mm) 99.3 98.7
Width Upper - Heel (mm) 76.5 76.0
Lace Stretch (1-5, 5 being stretchiest) 2 2.25
Flexibility of the heel counter (1-5, 5 being the stiffest) 3 2.2
Tongue: gusset type both sides -
Heel: pull tab none -
Midsole
Width Midsole - Forefoot (mm) 109.5 112.7
Width Midsole - Heel (mm) 80.7 89.1
Stack - Forefoot with insole (mm) 23.1 24.9
Stack - Heel with insole (mm) 31.8 32.8
Durometer Midsole Heel (Room temperature) (HA) 19.5 24.0
Outsole
Outsole thickness (Heel) (mm) 3.97 3.8
Outsole thickness (Forefoot) (mm) 3.97 3.9
Lugs Depth (mm) 4.35 3.1
Durometer Outsole Heel (Room temperature) (HC) 87.5 78.5
Insole
Insole Heel Thickness (mm) 4.4 4.5
Insole: removable yes  -

Tip: see the best running shoes.

Rankings

How Nike Air Zoom Pegasus 38 ranks compared to all other shoes
Top 32% road running shoes
All road running shoes
Top 33% Nike running shoes
All Nike running shoes
Top 31% neutral running shoes
All neutral running shoes

Popularity

The current trend of Nike Air Zoom Pegasus 38.
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Author
Paul Ronto
Paul Ronto

Over the past 20 years, Paul has climbed, hiked, and ran all over the world. He has summited peaks throughout the Americas, trekked through Africa, and tested his endurance in 24-hour trail races as well as 6 marathons. On average, he runs 30-50 miles a week in the foothills of Northern Colorado. His research is regularly cited in The New York Times, Washington Post, National Geographic, etc. On top of this, Paul is leading the running shoe lab where he cuts shoes apart and analyses every detail of the shoes that you might buy.