ASICS Magic Speed 4: review, carbon plate and best uses

The ASICS Magic Speed 4 running shoes are designed for fast training and road racing. They combine a full-length carbon plate with two cushioning foams and a firmer construction than many daily trainers. Their natural territory is interval work, changes of pace and races where the aim is to sustain a demanding effort.

They are not equally comfortable for every session: the fit is fairly snug and the plate adds stiffness. For someone who needs one pair mainly for easy running, a more flexible training shoe may be a more practical choice. The men’s version has a stated weight of around 240 grams per shoe.

Midsole and plate: what they bring to the run

The midsole combines FF BLAST PLUS and FF TURBO, with the latter positioned in the forefoot. The first forms the cushioning base; the second introduces a material intended to deliver a livelier response at toe-off. The result depends on more than one foam: the plate and the curved shape of the front of the shoe also play a part.

The carbon plate runs the full length of the shoe and adds stiffness to the platform. Together with the raised forefoot, it encourages a forward transition that differs from the feel of a flexible shoe. That does not mean it propels the runner by itself or guarantees a faster time: fit, pace and adaptation to the whole setup matter too.

In published laboratory tests, it took 26.5 N to bend the shoe, compared with an average of 15.5 N across the models measured. That difference helps explain why it may feel less natural for walking or easy jogging than a conventional trainer. During a faster session, its structure is designed to support a quicker transition.

Measured forefoot energy return was 61.8%, almost identical to the 61.5% average across the shoes tested. This is the result of a specific test, not a measure of how much energy every runner will recover during a race or a prediction of their finish time.

Stack height, drop and weight: figures depend on the measurement

A retail specification lists a stack height of 36 mm at the heel and 29 mm at the forefoot, giving a 7 mm drop. Drop is the height difference between those two areas. Laboratory measurements recorded 42.5 mm and 32.9 mm respectively, with a difference of 9.6 mm. The results are not interchangeable: measuring methods and the components included can alter the figures.

Stack height affects the distance between the foot and the ground, but on its own it does not describe either softness or stability. In this model, the raised platform sits alongside a stiff structure and a feel geared towards speed. A laboratory stack measurement does not automatically amount to competition certification; anyone entering a race with specific footwear rules should check the conditions that apply.

For weight, the men’s specification states around 240 g per shoe, while the laboratory measurement came in at 237 g. The figure changes with size and version, so it should not be applied uncritically to every pair. It is a relatively low weight for a plated shoe, although the fourth generation has gained volume over its predecessor.

Fit and sizing: a shape worth checking

The upper uses MOTION WRAP engineered mesh, with a thin tongue attached inside and a padded collar around the heel. The construction aims to hold the foot securely during pace changes without an especially bulky upper. The mesh also allows airflow, a useful quality during hard sessions and warm weather.

The fit is relatively snug and may not suit runners who need plenty of forefoot width. A laboratory measurement recorded 93.6 mm of width in one area of the upper, compared with an average of 95.2 mm. It is a reference for that sample, not a universal measurement for every size or a way to determine fit on its own.

To choose a size, measure foot length and compare it with the official ASICS size chart. When trying the pair on, check that the toes have room and that the heel does not move uncomfortably. For an online purchase, checking the exchange and return terms helps prevent a poor fit from becoming an expense that is difficult to recover.

ASICSGRIP outsole and use on wet surfaces

The ASICSGRIP rubber outsole is designed to provide traction on roads. In laboratory testing, it recorded a forefoot traction value of 0.81, compared with an average of 0.53. The figure points to a good result in that test, although it does not establish identical grip across every surface and condition.

An urban race can move between asphalt, road markings, metal covers and damp sections. Rubber is an important factor, but no outsole eliminates the risk of slipping on a smooth or wet surface. The shoe can also be used on a track, while loose gravel and uneven paths fall outside its main intended use.

The outsole wear test recorded a depth of 0.9 mm, compared with an average of 1.1 mm. That is a favourable sign within that test, not a mileage estimate. Wear can also appear in the midsole or the fit of the upper before the rubber is visibly worn down.

Where its pace and distance range makes most sense

The Magic Speed 4 suits intervals, threshold sessions and changes of pace, where its stiffness and geometry have a clear purpose. It can also be used for 5K and 10K races or a half marathon. There is no universal minimum pace at which a plate starts to work: how the runner adapts to the whole shoe matters more than an isolated number on a watch.

For a marathon, the decision requires considering how well the firm feel is tolerated over several hours. A shoe that feels comfortable during a short interval will not necessarily fit the same way after a long run. Trying it in progressively longer training sessions allows the runner to learn how it responds without wearing it for the first time on race day.

Someone who runs most of their miles at an easy pace may get more value from a daily trainer as their first pair and reserve this shoe for harder days. By contrast, if a comfortable trainer is already in the rotation, the fourth Magic Speed adds a dedicated option for faster sessions without having to be used for every run.

Who the shoe is designed for

This is a neutral running shoe, rather than a corrective stability model. Its structure may suit someone who prefers a firm platform, but it does not replace a specific solution when an individual support need exists. The plate’s stiffness and the upper’s fit matter as much to the choice as the neutral label.

A retail specification suggests the model for runners weighing between 65 and 75 kg, but that range should not be treated as a mandatory weight limit. Two people of the same weight may prefer different cushioning and fits. To decide whether it is worthwhile, comfort, session type and intended race distance are more useful considerations.

Nor does the plate make this an essential purchase for improvement. A recreational runner may benefit from it in training and races if they enjoy how it behaves, but paying for carbon does not guarantee faster running. If the stiffness is uncomfortable or the budget allows only one pair for daily miles, a shoe without a plate may meet that need better.

Price and position against the previous generation

The model’s reference price has been around €179.99, although the selling price varies by retailer, size and availability. When comparing an offer, check the final cost, including any delivery charges, and the return conditions. No fixed discount can be assumed to be current.

Compared with the Magic Speed 3, the fourth version opts for more midsole height and greater volume, with FF TURBO in the forefoot. That change alters the shoe’s balance: someone who appreciated the previous generation’s closer-to-the-ground feel should not assume the new model will behave in the same way.

The role of recycled materials

At least 50% of the upper’s main material comes from recycled materials. This describes the upper, not the proportion of the entire shoe. Separately, ASICS describes a sockliner dyeing process that reduces water use and carbon emissions compared with conventional dyeing.

These figures help put one part of manufacturing into context, but they do not amount to a complete measurement of the product’s environmental impact. The pair’s useful life, transport and what happens at the end of its use also contribute to that impact, although they cannot be summed up by the recycled content of a single component.

How we put this review together: we have not tested these shoes. We wrote it by reading published lab tests, brand information and runners’ opinions.

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