Written by

Brandon Law

Marathon Runner and Shoe Expert
The Rival Fly is an old school tempo trainer; the Pegasus is the classic daily trainer. Here we will be comparing these two trainers.

The Nike Rival Fly 3 is a lightweight tempo trainer which is built for speed. It has a thicker, more cushioned midsole than its predecessor and it costs $100.

The Nike Pegasus 39 is a workhorse built for daily runs. It has an updated, more comfortable upper and midsole than the Pegasus 38 and it costs $130.

Which one of these trainers is better for you?

Similarity and differences: Air Zoom Rival Fly 3 vs Air Zoom Pegasus 39

Air Zoom Rival Fly 3

Air Zoom Pegasus 39

Expert score
Expert score
Expert score
8.40 oz
9.20 oz
Heel Drop
8 mm
10 mm
The Nike Air Zoom Rival Fly 3 is an old school, lightweight tempo trainer with a flexible forefoot and a natural ride. It's best suited to short, speed workouts but it can also handle long distances. Version 3 of the Rival Fly has been updated with a softer Cushlon midsole and a thicker, more comfortable upper which makes it a better daily trainer.
The Nike Air Zoom Pegasus 39 is a comfortable, mid-range daily trainer designed to be durable. It doesn’t have an exciting or lively ride but it’s great bang for your buck and very stable. The 39th version has a new upper, midsole and outsole but the biggest upgrade is that it has lost an ounce of weight.
Recommended for
Speedwork, daily training
Daily training
Cushioning type
Cushioning amount
Medium cushioning
Medium cushioning
very stable
very stable
true to size
true to size
Retail price

Sole unit: Air Zoom Rival Fly 3 vs Air Zoom Pegasus 39

The Rival Fly 3’s midsole is made of Cushlon foam which used to be in previous versions of the Pegasus. It has a medium soft ride and is suitable for a variety of distances up to a full marathon.

The midsole of the Pegasus 39 is made of the newer React foam which is slightly softer and more cushioned than the midsole of the Rival Fly 3.

The Rival Fly 3 is better suited to shorter, faster runs because it is lighter and firmer. The Pegasus 39 is better suited to slower and longer runs because of its higher level of cushioning and long-distance comfort.

Both the Pegasus 39 and the Rival Fly 3 have forefoot Zoom Air units. The one in the Rival Fly 3 is smaller and is situated under the ball of the foot only. The one in the Pegasus 38 is larger and covers the entire forefoot. The Pegasus 39 also has an additional Zoom Air unit in its heel for extra cushioning and responsiveness.

Stability is better in the Rival Fly 3 because it has a firmer midsole with less lean bias. It also has a thinner midsole so your foot sits lower to the ground.

Ride transitions are smoother in the Pegasus 39 due to its larger forefoot Zoom Air unit. In the Rival Fly 3, you can feel the outline of the air unit which makes the forefoot feel lumpy.

The outsole of the Pegasus 39 has more rubber than the outsole of the Rival Fly 3 so it is more durable and can handle higher mileage. Both trainers use hard, durable rubber so they have higher levels of durability than other trainers in their classes.

Upper unit: Air Zoom Rival Fly 3 vs Air Zoom Pegasus 39

The upper of the Rival Fly 3 is made of engineered mesh. It has a flat, racing-inspired tongue which is sleeved so there is no tongue slide. Foot lockdown is excellent and the Rival Fly 3 runs true to size.

The upper of the Pegasus 39 is also engineered mesh but it’s thicker and warmer than the Rival Fly 3’s upper. It has a padded, longer tongue than the one on the Rivals Fly 3 so the Pegasus 39 is the more comfortable shoe. It fits true to size but is also available in narrow, wide and extra wide versions.

Which one to buy: Air Zoom Rival Fly 3 vs Air Zoom Pegasus 39

If you’re looking for a light training shoe for mainly tempo runs and interval workouts, the Rival Fly 3 is the shoe for you. It has a comfortable upper and a forefoot Zoom Air unit which makes it easier to pick up the pace. It’s also very cushioned and is great value for money.

If you’re looking for a more durable trainer for slower-paced daily training, the Pegasus 39 is the shoe for you. It has more cushioning so it can be used for longer distance runs and it has a more comfortable upper than the Rival Fly 3. The Pegasus 39 has an outsole with more rubber on it so it’s heavier than the Rival Fly 3 and it also costs $30 more.

This expert review is written by

Brandon Law

Marathon Runner and Shoe Expert
Brandon is a South African who lives and trains in Malaysia. He is a marathon runner who eats, sleeps and dreams running shoes. While most people wear shoes to run, he runs to wear shoes.