Finding the right running shoes is one of the most important steps in staying comfortable, preventing injury, and enjoying every run. While many runners focus on the latest shoe technology, the fit of your shoes is what really makes the difference.
At Sidas, we've spent decades helping runners achieve better foot comfort with insoles, socks and foot analysis technology. Here's our simple guide to choosing the right size running shoes.
Why Shoe Size Matters
Running in shoes that are too small or too big can lead to:
- Blisters
- Black toenails
- Pressure points
- Heel slipping
- Reduced stability
- Foot pain and discomfort
Your running shoes should feel secure without being tight. Your feet shouldn't slide around, but they also shouldn't feel squeezed.
Leave Room for Your Feet
Your feet naturally swell during a run, especially on longer distances or in warm weather. That's why running shoes should have extra space in front of your toes.
A good rule of thumb is to leave around a thumb's width (approximately 10–15mm) between your longest toe and the end of the shoe. This extra space helps prevent your toes from hitting the front of the shoe while running.
Don't Assume Your Usual Shoe Size
Running shoe sizing varies between brands and even between different models from the same manufacturer. Instead of relying on your everyday shoe size:
- Try shoes on before buying if possible.
- Measure both the length and width of your feet.
- Test shoes later in the day when your feet are naturally slightly larger.
Think About Width Too
Length isn't everything. Many runners experience discomfort simply because their shoes are too narrow.
If you have wider feet, look for shoes with a roomier fit rather than simply buying a longer shoe. A specialist running retailer can help you find brands and models that suit your foot shape.
Wear Your Running Socks
Always try on running shoes with the socks you plan to wear.
Technical running socks, like Sidas Running Socks, are designed to provide targeted support, improve moisture management and reduce friction, helping to minimise the risk of blisters while ensuring a more accurate fit inside your shoes.
Consider Your Insoles
If you wear custom orthotics or supportive insoles, bring them when trying on shoes. The right shoe should comfortably accommodate both your foot and your insole.
Sidas performance insoles can also enhance comfort, cushioning and support once you've found the right running shoe.
The Bottom Line
The perfect running shoe isn't necessarily the most expensive or the one worn by elite athletes—it's the one that fits your feet best.
Take the time to find the right fit, wear quality technical socks, and consider supportive insoles to maximise comfort on every run. Your feet will thank you, whether you're heading out for a 5K or training for your next marathon.