I found the following guide on important things to consider when buying running shoes at Asics shoe website.
1. Shop by activity. Sport specific shoes help prevent injuries by
delivering function and support for the intended use. Running and
walking shoes are made for straight-forward activities. Whereas
Netball, Tennis and other court-shoes provide additional support for
lateral motion. If you walk, buy a walking shoe!
2. Understand your foot. Seek advice from a podiatrist or retailer; ask
them to assess your foot type and recommend a shoe to suit. Many people
aren’t aware that ASICS has developed different shoes for the various
foot types – high arch, normal arch, and flat feet.
3. If the shoe fits; wear it. As a general guide leave one finger’s
width (1cm) between your longest toe and the end of the shoe, however
this is open to personal preference. Ensure your heel does not move
excessively. Only you will know if the shoe feels comfortable. If in doubt – get out!
4. Be aware of width and fit options on certain models. If you have a
narrow foot opt for a standard fit in men’s and AA fit for women. For
average width, keep an eye out for shoes in a 2E fit for men and
standard fit for women. And if you have wide feet check out 4E shoes
for men and D fit in women’s. Shoes such as the ASICS GT2110 come in
various widths so ask the retailer about the available options ASICS
5. Wear the socks and or orthotics you normally wear for the activity.
Never place orthotic devices directly on top of the standard innersole
– unless advised by a qualified medical practitioner.
6. Our feet tend to swell in the afternoon – so be aware of this. Try
and shop for shoes around the same time of day you would normally
participate in your activities.
7. Ask questions. The retailers are educated on shoe technology, so use
their knowledge to find a comfortable shoe. Asking questions on shoe
features and functions will help you make an informed decision.
8. Try on both left and right shoes as one foot is usually slightly bigger than the other.
Within reason, walk or run in the store if possible. Ensure they are comfortable.
9. When to update? Running shoes should generally last for approx
800 – 1,000km.
However this depends on the individual’s technique and activity. You
can usually feel or see the midsole of the shoe compressing after some
time. This is a good indication that the shoe may be starting to lose
its full support and function.
10. Ultimately – the shoe should be flexible, comfortable and breathable.