Should Running Shoes Be Flat or Cushioned? What Really Works for Your Feet

Every runner has stood in a shoe store, staring at rows of running shoes, wondering: should I pick the flat ones or the cushioned ones? It’s not just about comfort-it’s about injury risk, performance, and how your body moves over time. The answer isn’t simple, and the marketing claims don’t help. Brands scream about ‘maximum cushioning’ or ‘barefoot feel,’ but what does that actually mean for your knees, arches, or shins?

What Does ‘Flat’ or ‘Cushioned’ Even Mean?

When people talk about flat running shoes, they usually mean low-drop shoes-those with little difference in height between the heel and the forefoot. Most traditional running shoes have a 10-12mm drop. Flat shoes drop to 4mm or less. Some minimalist shoes go down to 0mm. Cushioned shoes, on the other hand, are thick under the heel, often with foam layers that squish under pressure. Brands like Hoka, Brooks Ghost, and Asics Gel-Nimbus fall into this camp.

The key number to look for is the heel-to-toe drop. It’s not just about thickness-it’s about how your foot lands and pushes off. A 12mm drop encourages a heel strike. A 4mm drop encourages a midfoot or forefoot landing. That change alters how force travels through your legs.

Why Cushioned Shoes Became the Default

In the 1980s and 90s, running shoe companies started adding more foam, more support, more structure. The idea was simple: more cushioning = less impact = fewer injuries. It made sense on paper. Runners in big, soft shoes felt like they were floating. Sales soared. By 2010, over 80% of runners wore shoes with 10mm+ drop.

But here’s the twist: studies from the British Journal of Sports Medicine and Harvard’s Running Lab found no clear link between cushioning and reduced injury rates. In fact, runners in highly cushioned shoes often land harder because their brains think, ‘The shoe will protect me.’ They don’t adjust their stride. The result? More stress on hips and knees, not less.

What Flat Shoes Actually Do to Your Body

Flat shoes force your foot and calf to work harder. Your Achilles tendon and plantar fascia become stronger. Your arches engage. Your ankles stabilize more. That’s not a bad thing-if your body is ready for it.

Many elite distance runners wear low-drop shoes. Kenyan and Ethiopian athletes often train in shoes with 4-6mm drop. Why? Because they’ve built the strength to use their natural spring mechanism-the tendons and muscles in their feet and calves-that act like rubber bands, storing and releasing energy with each step.

But here’s the catch: switching to flat shoes too fast causes problems. Runners who went from 12mm drop to 0mm in a month ended up with Achilles tendonitis, plantar fasciitis, or stress fractures. It’s not the shoe. It’s the transition.

Who Should Wear Cushioned Shoes?

You might need cushioning if:

• You’re over 60 and have osteoarthritis in your knees or hips
• You’ve had a history of shin splints or stress fractures
• You run on concrete or asphalt every day and your body can’t absorb the shock
• You’re carrying extra weight and your joints need more protection
• You’re training for a marathon and logging 60+ miles a week

There’s no shame in needing cushion. Your body isn’t broken. It just needs support. A 2023 study in Medicine & Science in Sports & Exercise showed runners with knee osteoarthritis had 27% less pain when switching to high-cushion shoes compared to minimalist ones.

Who Should Try Flat Shoes?

Flat shoes work best if:

• You’ve been running for 3+ years without major injuries
• Your calves and feet feel strong, not tight
• You run on trails, grass, or softer surfaces most of the time
• You want to improve your form, not just your mileage
• You’re aiming for faster race times and want more ground feel

Many runners in Dublin’s Phoenix Park switch to flat shoes in spring. The softer ground gives them room to adapt. One runner I know, a 45-year-old teacher, dropped from 10mm to 4mm over six months. His plantar fasciitis vanished. He now runs 5Ks in 18 minutes flat.

The Middle Ground: Transition Shoes

You don’t have to go all-in. There’s a sweet spot in the middle. Shoes like the Nike Pegasus (8mm drop), Saucony Ride (8mm), or New Balance 880 (10mm) offer moderate cushioning without being too soft. They’re a good starting point if you’re unsure.

Try this: wear your current shoes for 80% of your runs. Use a moderate-drop shoe (6-8mm) for one or two shorter runs a week. After four weeks, swap them. After eight weeks, reassess. How do your calves feel? Your arches? Your knees?

How to Test Your Current Shoes

Grab a ruler. Place your shoe flat on the ground. Measure from the ground to the highest point of the heel. Then measure the forefoot. Subtract the two numbers. That’s your drop.

• 0-4mm: Minimalist / Flat
• 5-8mm: Moderate / Transition
• 9-12mm: Standard / Cushioned
• 13mm+: Max Cushion

Now, look at the wear pattern on your old shoes. If the heel is worn down more than the front, you’re a heel striker. That doesn’t mean you’re doing it wrong-but it does mean cushioning might help. If the front is worn more, you’re likely a midfoot runner. Flat shoes could suit you better.

What Happens When You Switch?

Switching from cushioned to flat? Expect sore calves. Tight Achilles. Maybe some foot fatigue. That’s normal. It’s your body learning to use muscles you’ve been ignoring.

Switching from flat to cushioned? You might feel lazy at first. Like you’re floating. But if you’ve got joint pain, it could be a game-changer.

Never switch overnight. Give yourself 8-12 weeks. Start with 10% of your weekly mileage in the new shoe. Walk around the house in them. Do calf raises. Stretch your plantar fascia. Roll your feet on a tennis ball.

The Real Answer: It Depends on You

There’s no universal best shoe. The best shoe is the one your body can handle right now. A 22-year-old college runner with strong calves and no injury history? She might thrive in a 4mm drop. A 58-year-old runner with arthritis? He’ll likely stay happier in a 10mm cushioned shoe.

Listen to your body. If your knees ache after a run in flat shoes, don’t push through. It’s not ‘being tough.’ It’s ignoring signals. If your feet feel weak and tired in cushioned shoes, maybe you’re not using your own strength anymore.

Try both. Test them. Track how you feel. Your feet will tell you what they need.

Next Steps: How to Decide

Here’s your simple plan:

1. Check your current shoe’s heel-to-toe drop with a ruler.
2. Ask yourself: Do you have pain? Where? Knees? Shins? Feet?
3. Try a moderate-drop shoe (6-8mm) for two weeks on two runs per week.
4. Track how you feel after each run-no pain? Great. Sore calves? Slow down.
5. After a month, decide: do you feel stronger, faster, or more comfortable?

There’s no trophy for running in the flattest shoe. The goal isn’t to look like a pro athlete. It’s to run without pain, for years. Your feet know what they need. You just have to listen.