New Balance SC Trainer V3 vs Saucony Endorphin Speed 4: Which Super Trainer Deserves Your Money?

Introduction

The New Balance SC Trainer V3 and the Saucony Endorphin Speed 4 are two of the most complete super trainers you can currently put on your feet, but they go about the job in noticeably different ways. One leans towards plush cushioning and long cruising miles, the other towards a lighter, more direct and faster feel. This comparison breaks down the design differences, ride character, fit and value of both to help you decide which suits your training best.

Stack, Weight and Price at a Glance

The Saucony Endorphin Speed 4 carries 36mm of foam in the heel and 28mm in the forefoot for an 8mm drop. The New Balance SC Trainer V3 goes bigger, with 40mm in the heel and 34mm in the forefoot for a lower 6mm drop.

In a UK men’s 9, the Endorphin Speed 4 weighs 255g (9oz), while the SC Trainer V3 comes in at 282g (9.9oz). On price, the Speed 4 has an RRP of £180 in the UK or $170 in the US. The SC Trainer V3 lands at a hefty £230 in the UK, though just $180 in the US, only ten dollars more than the Saucony.

Midsoles: Two Very Different Recipes

The Endorphin Speed 4 uses PWRRUN PB foam paired with a winged nylon plate and Saucony’s Speedroll rocker shaping. The nylon plate adds stability, rigidity and a touch of forefoot flexibility, and sits slightly lower in the midsole so there is more foam directly underfoot.

The SC Trainer V3 takes a different route with a FuelCell midsole, a reformulated EVA and Pebax blend that now carries 20 percent Pebax. That is the same foam family as the New Balance Rebel v4. The carbon plate is fork-shaped here to reduce weight and increase flexibility for a more natural feel underfoot. New Balance’s Energy Arc, a trench down the middle of the midsole, is designed to let the carbon plate flatten on landings and spring back on toe-off.

Underfoot geometry differs too: the SC Trainer V3 has a wider forefoot platform, but is narrower in the heel than the Speed 4. Both shoes wear generous outsole rubber with large forefoot coverage and protection in the trouble-prone heel areas. The SC Trainer V3 has a thicker protective layer, though grip is good on both for the needs of a faster daily shoe.

Uppers and Build

Up top, the Endorphin Speed 4 has a zonal mesh upper with a light, airy perforated design and plenty of flex in the toebox. The SC Trainer V3 uses an engineered mesh upper with New Balance’s Phantom fit technology, the same approach as the SC Elite v4. The New Balance upper is marginally thicker than the Speed 4’s.

Both heel collars are medium padded, with the SC Trainer V3 offering a little more padding at the top of the heel and internal heel counters that rise slightly higher. Both tongues are gusseted and medium padded, but the Speed 4’s tongue is noticeably more flimsy and knitted, and does not wrap the top of the foot quite as well as the SC Trainer V3’s.

Fit and Sizing: Roomy vs Race Fit

Both shoes offer a roomy, disappearing fit with genuinely generous toeboxes, but there are real differences in how they hold the foot. In the SC Trainer V3, going half a size up (as New Balance recommends) yields plenty of length, perhaps bordering on a touch too much, with lots of wiggle room and nicely flexing uppers. Locking down the midfoot took a bit of fussing, and heel hold required careful lacing at first, with some initial slipping until the laces were dialled in.

The Endorphin Speed 4 is the more secure of the two out of the box, with great midfoot lockdown, well-balanced heel collar and tongue padding, and an easy on-foot feel. It is a bit more race fit than the SC Trainer V3, though not severely so. For the Speed 4, true to size works well; for the SC Trainer V3, half a size up suits those who want room for longer efforts, while regular size may suit fans of a snugger fit.

Testing across two sizes suggests sticking with your normal running shoe size for both, with the note that US sizing proved more consistent than UK sizing for comparing these models. Heel lockdown was secure in both, with no concerns in either shoe once fitted properly.

Ride and Performance

The ride differences are pronounced. The Endorphin Speed 4 feels far more direct: you feel the road more, with greater connection, responsiveness, precision and control. It feels lighter on the foot, almost like skipping along the ground, and the Speedroll rocker helps the foot flow at whatever pace you are working. It is lively without harshness, comfortable for cruising but genuinely built to perform when you push the pace, which is where the midsole, rocker and nylon plate come alive.

The SC Trainer V3 delivers more bounce and softness, with a much bigger cushioned feel. It feels like a stable daily trainer with an edge, great for absorbing long runs at easy to steady paces and short stints at marathon effort. It is less nimble at genuinely fast paces, but it is very comfortable to control a faster pace over long distances. Heel strikers and heavier runners will likely appreciate the extra forefoot protection on long cruising miles, and the wide platform plus noticeable foam sidewalls add a real sense of stability and support.

The Speed 4 does start to feel a little thin under the forefoot on hard long runs, where the SC Trainer V3’s extra foam pays off. Conversely, the SC Trainer V3 initially felt stiff and unimpressive on first run, but broke in softer and bouncier, and excelled across marathon training workouts including double workout days, 4x4K rep sessions and easy-to-steady 15-mile efforts.

In short: the Speed 4 is the better pick for faster all-out sessions and track work, and it can do everything the SC Trainer V3 can while adding more top-end speed. The SC Trainer V3 is the better cruiser, and the one to reach for if you favour cushion, bounce and protection over ground feel.

The Verdict

The Endorphin Speed 4 is the better all-rounder. It handles easy running beautifully and has a wider top-end range, making it the more appealing race-day option for anyone not going all-in on a premium carbon racing shoe. Some runners may find it too lightweight or slightly unstable for easy runs, and that is exactly where the SC Trainer V3 wins: more comfort, more stability, more support, and a genuinely accomplished long-run partner. It could also serve as a supportive, comfortable race-day model for runners who do not want a full carbon shoe.

Value shifts the picture further. In the UK, £230 for the SC Trainer V3 is a lot for a training shoe, no matter how good the tech, and the £180 Endorphin Speed 4 offers more run potential per pound. In the US, with only a ten-dollar gap, the choice comes down purely to ride preference: a lower, more precise, ground-feel-focused shoe, or a bigger, cushier, more protective platform. The only scenario where the SC Trainer V3 would be the first pick outright is a big road ultra, where its extra cushioning and support shine.

Conclusion

Both of these super trainers are excellent, but they suit different runners. Choose the Saucony Endorphin Speed 4 if you want a lighter, more direct, faster-feeling shoe with better value, especially in the UK. Choose the New Balance SC Trainer V3 if you prioritise cushioning, stability and comfort for long cruising miles, and the UK price does not put you off. For most runners focused on both training and racing, the Speed 4 remains the pick.