When Do You Change Your Running Shoes?
It’s a new year, do you need a new shoe?
If you consider that your feet strike the ground between 600 – 1,000 times per kilometre (depending on your pace) at 2.5 – 3.5 times your body weight while running, it follows that footwear plays a critical role in running enjoyment, performance and injury prevention.
Running shoes that are inappropriately sized, unsuitable for your unique biomechanics or training needs and/or have gone past their use-by date can cause a variety of injuries. Researchers have shown a significant correlation between infrequent changes of running shoes and injury.
What should your expectations be from your running shoe?
- Essentially it is very dependent on how much time you spend in your running shoes. As a general rule a good shoe will allow you to enjoy approximately 900 – 1,100km of running.
Why do running shoes get worn out?
- Research has demonstrated that the midsole material of a running shoe will last for approximately 700-1,000 kilometres or 6-12 months of running. This is dependent on the mileage and intensity of training. The midsole provides the important cushioning and stability to a shoe, so once it has worn out the shoe loses its functional stability and increases your injury risk.
- The outsole of a running shoe is made of durable compounds and is a poor indicator of remaining shoe life. In most cases, the midsole will wear out long before the outsole – especially for heavier runners.
Signs of Wear and Tear?
- You need to examine the major areas of decomposition – the heel counter, the midsole and the outsole – any extrinsic abnormality causes an imbalance of impact forces and may increase the risk of injury to your lower limbs.
- Look at the heel counter – is there any wearing on the inside or outside? Wearing on the inside can actually promote over-pronation and its associated overuse injuries, while wearing on the outside can occur even with a normal running gait pattern.
- Look at the midsole – is there any excessive compression, wrinkling or tilting? Monitor the torsional (twisting) stability of the shoe. Hold either ends of the shoe and twist in opposite directions – is there too much flexibility?
- Look at the outsole – have you worn through the rubber to the midsole? Can you start to feel the irregularities of the ground under your feet?
Tips on how to get a longer life out of your shoes.
- Reserve your running shoes for running only! Not gardening, hiking, cycling or creating a daggy walk to work outfit etc.
- Rotate your shoes: alternate between two pairs of running shoes so as to prolong the life of the midsole beyond that of wearing each pair consecutively. Thus:
- Use one pair for longer runs and any ‘events’ and the second pair only for shorter runs, inclement weather and any off-road runs.
- The first pair to reach 1000 km run, should be given a new job description, (i.e. gardening, hiking etc) and a new pair should be brought into the rotation.