Have you spent time looking at different kinds of running shoes? If so, you’ll probably have come across terms such as heel-to-toe drop, low drop and zero drop. But what are zero drop shoes exactly? And, more importantly, how does their design affect the way you walk or run? 

In general, heel-to-toe drop describes the difference in height between the heel and forefoot of a shoe. Zero drop footwear removes that height difference entirely, placing the heel and forefoot at the same level. 

For some runners and walkers, moving towards a lower-drop platform can encourage the feet, ankles and lower legs to play a more active role in movement, which can offer considerable benefits to the way you exercise. However, changing your footwear also changes where forces are absorbed by the body, so making the change gradually is important. 

What heel-to-toe drop means for your stride 

Let’s go back to the question: what does heel to toe drop mean? Heel-to-toe drop, sometimes called a shoe's offset, is the difference in height between the heel and forefoot, measured in millimetres. 

For example, if the heel sits 10 mm higher than the forefoot, the shoe has a 10 mm heel-to-toe drop. If the heel and forefoot sit at exactly the same height, the shoe has a 0 mm — or zero — drop. 

Broadly: 

Heel-to-toe drop should not be confused with stack height. Stack height refers to the total amount of material between your foot and the ground. A shoe can therefore be zero drop while still giving you a good amount of cushioning under the foot. 

Drop can influence how you move. Shoes with a larger heel-to-toe offset tend to reduce the amount of ankle movement required with each stride and can make a rearfoot or heel strike more comfortable. Lower-drop shoes generally ask more of the foot, ankle, Achilles tendon and calf. 

That does not automatically make one design better than another. It simply means the mechanical demands are different. 

What zero drop shoe design actually means 

So, what does a zero drop shoe mean in practical terms? In a true zero-drop shoe, the heel and forefoot are closer to the position of the foot when standing barefoot on a flat surface. 

Zero drop should not be confused with minimalist footwear. A zero-drop shoe does not have to be thin, highly flexible or minimally cushioned. 

Some zero-drop running shoes offer substantial cushioning and a high stack height, while others provide a much more flexible, ground-feeling experience. Both can technically be zero drop. 

When considering zero-drop footwear, it is therefore worth looking at the whole shoe, including: 

A wider, foot-shaped toe box is also often associated with zero-drop footwear, although the two features are separate. Allowing the toes more space to spread can support forefoot stability and natural toe movement. 

Why zero drop running shoes support natural foot biomechanics 

One of the main arguments for lower-drop footwear is that it allows the foot and lower leg to function in a position closer to barefoot movement. 

If you are wondering why zero drop running shoes have become popular among runners, physiotherapists and movement specialists, there are several potential benefits. 

Why low-to-zero drop platforms are good for runner health 

So, is zero drop good for runners? 

A useful way to think about low- and zero-drop footwear is not as a cure for injury, but as one way of encouraging the feet and lower legs to become more active during movement. 

Building foot and calf capacity 

Reducing heel-to-toe drop places greater demand on the calf, Achilles tendon, ankle and foot. 

The Altra Olympus, for example, combines a zero-drop platform with substantial cushioning. 

Do not force a particular foot strike 

Lower-drop footwear may naturally change the way you run, but deliberately forcing yourself onto your forefoot can overload the calves and Achilles tendon. 

Instead, focus on running comfortably, avoiding excessive overstriding and allowing your gait to adapt gradually. 

Some runners use very short periods of barefoot running on a safe, soft surface such as grass to become more aware of how their feet naturally land. Treat this as an additional training load and introduce it carefully. 

Increase running distance slowly 

Avoid making a major footwear change at the same time as sharply increasing your running volume. 

The familiar 10% weekly increase can be a useful guide, but your body's response matters more than following an exact percentage. 

If possible, transition during a quieter training period rather than immediately before a race. 

Expect some calf and foot fatigue 

Tight or tired calves are common during the transition to lower-drop footwear, particularly for runners who train on hills or trails. 

Useful strategies may include: 

Know when soreness needs attention 

Some temporary muscular soreness can be expected, but it should gradually settle rather than worsen. 

If pain remains significant beyond roughly 24–36 hours, affects normal walking or becomes increasingly localised, reduce the load and consider speaking to a physiotherapist, podiatrist, sports medicine doctor or other appropriately qualified healthcare professional.