Saucony Endorphin Trainer Introduction

The Kinvara Pro was one of the most underrated running shoes of 2023. For me, it was an excellent speed trainer and a much better training companion than the Endorphin Speed.

I loved how stiff its midsole was and how much deep cushioning it provided. It also had good stability and a really comfortable upper. I find it strange that not many runners who tried it liked it.

While it wasn’t the most energetic trainer, it filled a role which wasn’t present in the Saucony lineup: a maximalist, rigid trainer with very little ground feel. It was Saucony’s version of the Skyward X or the Prime X 2.

The Kinvara Pro has been rebranded as the Endorphin Trainer and I think this is a much better name for it. The Kinvara Pro had nothing in common with the regular Kinvara. The new name also tells us that it’s in the Endorphin family and it’s a training companion to the Endorphin Elite and Endorphin Pro.

When the Saucony Endorphin family was first launched in 2020, it consisted of 3 shoes: the Speed, the Pro and the Shift. The Speed and Pro still exist but the Shift was discontinued. It was the daily trainer in the lineup.

Over the years, the Speed has become a daily trainer for many runners because of its versatility and its balanced ride. Now, you have the option of the Speed and the Trainer (within the Endorphin range) for your training run needs.

The Endorphin Trainer weighs 9.9 oz (280 g) for a men’s US 9. This makes it 0.4 oz (11 g) heavier than the Kinvara Pro. It measures 41 mm in the heel, 33 mm in the forefoot, 1 mm lower in both the heel and forefoot than its predecessor. It costs the same as the Kinvara Pro.

Saucony Endorphin Trainer First Impressions

The first thing I noticed when putting the shoe on was how much plusher the midsole felt. My feet sank down into the foam much more than in the Kinvara Pro.

The other thing which I noticed was the improved upper fit. It felt more spacious and the new upper material conformed to my feet better.

My first run was a hill sprints workout consisting of 10 x 100 m intervals. The new midsole made the ride feel softer and more energetic and it was really easy to increase my power on the uphill sections. I was excited about the changes that Saucony had made.

Saucony Endorphin Trainer Upper

The Endorphin Trainer’s upper feels more comfortable than the Kinvara Pro’s due to the more accommodating fit. The softer engineered mesh stretches and conforms to your feet much better. Breathability has also improved because the mesh is thinner and more porous.

There’s a small amount of padding in the tongue and the collar, so it feels comfortable without being overly puffy. The tongue is gusseted and it has wide wings to hold it in place; there’s no tongue slide.

The fit is true to size and is best suited to runners with high volume feet because of how spacious the upper is. It’s also suitable for runners with wide feet. There are 3 small reflective circles on the heel for safety.

Saucony Endorphin Trainer Sole Unit

The Endorphin Trainer is the spiritual successor of the Endorphin Shift. Both of them are versatile, do-it-all trainers with stiff midsoles. The Endorphin Trainer is a new generation super trainer though, with better midsole foams and a ¾ length carbon plate so its ride feels modern and more dynamic.

From a design perspective, not much has changed from the Kinvara Pro. It still uses 2 different midsole foams and a thick PWRRUN+ insole. The main difference is that the upper midsole layer is now Saucony’s latest premier racing foam, IncrediRun.

IncrediRun is by far the softest midsole foam I’ve ever experienced and I found it way too soft in the Endorphin Elite 2. In the Trainer, the bottom layer of PWRRUN is very firm so there’s a stark contrast between these 2 layers and as a result, it may feel clunky to some runners.

The firm PWRRUN section is there for durability and stability; the marshmallow-like IncrediRun is there for comfort and energy return.

It’s an excellent long run trainer. Not only does it have very deep cushioning but it also has a very stable ride thanks to the firm PWRRUN bottom layer. The stiff midsole results in a forefoot rocker which feels efficient and energy-saving during those 25+ kilometre long, marathon slogs.

The Endorphin Trainer has a softer ride than the Kinvara Pro and it feels bouncier because the layer of IncrediRun returns more energy. It feels a lot more natural at slower paces than its predecessor. You also get the signature Saucony thick PWRRUN+ insole which makes it feel even plusher and more deeply cushioned.

Because they’ve made the ride softer, they’ve also had to tune the carbon plate. It’s now more flexible but it still provides plenty of propulsion during toe-offs. It’s not nearly as bendy as the Endorphin Speed 4’s plate so it feels like a speed trainer, not a daily trainer.

It makes it really easy to pick up the pace and it feels great on tempo, threshold and hill sprints. It has a wide pace range so it’s a great shoe to take with you on a trip because it can do most types of runs well.

The PWRRUN layer of the midsole forms most of the outsole. A new addition is that the outer lateral heel and the medial toe-off areas get proper rubber for better grip and durability.

I haven’t noticed any excessive outsole wear during my testing of the Endorphin Trainer but because of its lack of full rubber coverage, the outsole is subpar when it comes to traction on wet surfaces.

Saucony Endorphin Trainer Conclusions

If you didn’t like the Kinvara Pro, chances are high that you won’t like the Endorphin Trainer. It’s for runners who are seeking a stable ride with minimal ground feel and a stiff midsole. It’s perfect for long runs but it also has the ability to pick up the pace.

The Endorphin Trainer is an upgrade over the Kinvara Pro. It has a more energetic ride, a comfier upper and better outsole durability. I just wish it hadn’t picked up weight. It will still stay in my rotation because it’s a workhorse that absorbs impact well. It has more cushioning than the Ride 18 and the Endorphin Speed 4, and it feels more dynamic.

Saucony definitely needs to switch out the firm, dull PWRRUN for something livelier. PWRRUN PB as the bottom layer would be a good replacement that would make it lighter.

At $180, it’s good value for money. It’s only $10 more than the Speed but you’re getting a carbon plate instead of nylon and you’re getting IncrediRun, Saucony’s latest super foam. It’s also a lot cheaper than the Skyward X ($225) and the Prime X 2 ($300) which are comparable to the Endorphin Trainer.