At ARION we are on a mission to decode human movement. After a decade of research, six years of operation, and thousands of hours of recorded movement data, one thing has become very clear to us. Movement is exceptionally unique.

We all have our own body types, varied techniques, unique philosophies and personal goals. All of these elements heavily influence the way we move. Each contributing to our individual biomechanical profile, is what we call, your unique running identity.

To explore this, in this content series we will highlight that there is no such thing as the perfect running shoes. It all depends on your own completely unique biomechanics and your individual goals. We will be testing eight of the latest and greatest running shoes. Utilising our groundbreaking technology shows how one shoe can have two very drastic results on two very seemingly similar people.

We don’t review the shoes based on their general performance. We simply highlight the diverse results generated across different people. Each month we will put a new pair of shoes to the test before finally reviewing it all together with a final summary of our movement experiment.

As always, it’s the same conditions (treadmill), same shoe, same size, same pace, same distance, very different results! Fourth up is the Saucony Endorphin Speed 3…


Saucony Endorphin Speed 3

The Saucony Endorphin Speed 3 is a neutral running shoe with a heel-to-toe drop of 8mm. The running shoe is known for its SPEEDROLL Technology that helps you forward effortlessly. Together with its ultra-light and responsive PWRRUNPB foam cushioning, the shoes give you a light and fast feeling. The Saucony Endorphin Speed 3 is designed with a new winged plate that helps support your run from toe-off to landing. A shoe that fits your needs to push your pace with ease.


1. The Runners

Let’s introduce our runners. Runner 1 is Manouk. She runs around once every two weeks for a longer run, and every week a couple of short runs to conduct research for ARION. Her preferred distance is around 5k with a pace between 5:15 and 5:30 min/km. A future goal for Manouk is to finish a quarter triathlon. She likes to run because she wants to stay in shape and doesn’t have time to take part in other sports.

Our second runner, runner 2 is Elzemieke. She runs around three times a week for long runs. Her preferred distance is around 5k with a pace between 6:15 and 6:30 min/km. A short-term goal for Elzemieke is to run a 10k race. Elzemieke likes to run because it clears her mind and to stay in shape.

For both runners, we will compare the Nike ZoomX Vaporfly Next 2% to a baseline shoe. This baseline shoe will be an average of how both runners run. For both runners, the baseline shoe is a neutral running shoe with a lower heel-toe drop and stack height (low mid-sole thickness). With this baseline shoe, Manouk is a forefoot lander and Elzemieke is a rearfoot lander. Manouk is neutrally balanced whereas Elzemieke uses her left foot a little more than her right. Both runners have an average cadence for a recreational runner and a relatively high stability profile with little variation in the foot placement with each step.


2. The Results


3. The Insights



Let’s first compare both shoes on their effects at footstrike. Remember that a footstrike of 0% would indicate a foot landing that is as far as possible towards the heel, and a footstrike of 100% indicates the foot lands right at the tip of the toes. In our baseline shoe, we’ve already seen that Elzemieke is a rearfoot lander, landing her foot a little bit away from the back of the heel with a footstrike of 16% in the baseline shoe. On the other hand, in the exact same shoe, Manouk is very clearly a forefoot lander with a footstrike of 78.2% when wearing the same baseline shoe.

At 8 mm, the Saucony shoe has a relatively high heel-toe drop which often encourages runners to land more towards their heels. For Elzemieke, her rearfoot strike became even more pronounced by moving from 16% to 9.1%. Similarly, Manouk’s footstrike moves back from 78.2% in the baseline shoe, to a less extreme forefoot landing at 73.1%.

When looking at how the foot is placed on the ground from the outside to the inside of the foot we can see differences in how both runners respond to the shoe. This metric is referred to as Footstrike X, where 0% indicates the foot lands entirely on the inside of the foot and 100% entirely on the outside of the foot. Elzemieke landed more on the outside of her foot in the baseline shoe (62%), but now lands more centrally with the Saucony (54.2%). Similarly, but to a lesser extent, Manouk’s landing moved a little away from the outside of the foot with the Saucony as compared to the baseline shoe with a Footstrike X of 77.2% in the Saucony shoe and 80.8% in the baseline shoe. Note however that 77.2% still reflects a landing that is mostly towards the outside of the shoe.



For Manouk, the Saucony shoe results in a slight increase in the loading on the calf muscles. While Elzemieke does not show a clear difference in the loading at different structures. This highlights the different responses of two individuals to the same shoe.


Contact time and cadence

Manouk’s contact time decreased from 262 ms in the baseline shoe to 252 ms in the Saucony shoe, while her cadence remained similar at 158 steps per minute (spm). For Elzemieke we also see a slightly shorter contact time in the Saucony shoe as compared to the baseline shoe (291 vs 299 ms), while her cadence also remains exactly similar at 155 spm.

The flight time for Manouk increased from 117 ms in the baseline shoe to 128 ms in the Saucony shoe. Similarly, for Elzemieke, flight time increases slightly from 88 to 95 ms. This means that both runners spend less time on the ground, and more time in the air in the Saucony shoes, suggesting a more reactive and potentially more efficient running style. Suggesting also that both runners have much more benefit (amongst other metrics and indicators) towards running efficiency with the Saucony compared to the baseline shoe.


Stability and balance

Stability indicates how consistently the foot is placed on the ground. Slightly varying the way your foot contacts the ground, and thus decreasing stability, may reduce injury risk as there is more variation in how the load is applied to the body. Conversely, when the stability metric value is too high, it indicates there is very little variation in how the foot is placed on the ground, potentially increasing the risk of injury. Stability X refers to the variation of your landing between steps relative to the width of your foot. Stability Y refers to the variation of your landing between steps relative to the length of your foot. For Manouk, both the Stability Y and X were lower (97.8% vs 98.1% for Y and 97.6 vs 98.7% for X) in the Saucony shoe. Elzemieke showed a slightly higher stability Y in the Saucony shoe when compared to the baseline shoe (98.8 vs 98.6%), while Stability X was slightly lower with 98.4 vs 98.7%. This again shows that two runners can respond differently to the same shoe.

Balance indicates how much more or less you use one foot over the other. A balance equal to 0% means you use both feet equally. When your balance is negative you use your left foot more and when it is positive you use your right foot more. Elzemieke used her left foot more in the baseline shoe (-2%) and used her right foot a little more in the Saucony shoe (0.7%) and was overall slightly more equally balanced. On the other hand, Manouk was overall slightly less equally balanced when using the Saucony shoe. Manouk already used her right foot slightly more when using the baseline shoe, and this increased a little from 0.6% to 1.5% when using the Saucony shoe.


Movement is unique

If we step back from all the data insights, the findings suggest that both Manouk and Elzemieke enjoy some benefits of this shoe, albeit, in slightly different ways. Both runners appear to run a little more reactively and potentially more efficiently with the Saucony shoe. The more central footstrike and less extreme forefoot landing may help Manouk with a more even distribution of loading during her running. On the other hand, whilst Elzemieke had a more central balance in the Saucony, she may find that this shoe slightly increases the loading in her knees and upper leg.

The unique combination of your personal running characteristics and the available shoe technologies is the reason why at ARION, we focus on your unique running identity, combining your individual biomechanics with specific shoe technologies that bring you the biggest possible benefits. Stay tuned as we continue to test another pair of the latest and greatest running shoes every two weeks and start to explore some comparisons between the different shoes that we test.

If you want to discover your running identity visit your nearest HUB in one of our ARIONHUB stores to learn more.