After all the rain we have had lately, yesterday and today have been beautiful again, with temperatures ranging from 50F to 75F, dry and sunny with light winds. I was able to really enjoy my long run yesterday: it started cool, but was quite warm enough by the end. However, at the end I felt quite tired and was feeling a little pain.

Pain at the end of a run is always a warning sign, and an indication to figure out what caused it. When I did an easy run today, the pain was still there, but not as severely as yesterday. That's good, because it means that I am not suffering from an overuse injury.

I got to thinking about what might have caused it, and remembered similar experiences with pain on my last few long runs. Then it dawned on me: it was my running shoes.

I have several pairs of running shoes, and rotate them between my different runs. I have a Saucony pair and a Brookes pair that I tend to use for easy runs and occasionally other runs, including races. I have Mizuno pair that are light, that I keep for my faster or more demanding short runs, such as intervals. And for my long runs I generally wear my New Balance, which are slightly heavier than the other shoes.

It just happens that the New Balance are also my oldest running shoes. They don't show all that much wear, but I'm inclined to suspect the midsole has broken down. (The midsole is the part between the inner sockliner and the outer sole, so you really don't ever see it.)

In fact, keeping one pair of shoes for each type of run is not brilliant. For example, if you keep one pair for long runs, like I did, you don't know if pain that you get is caused by the type of run or the running shoes! In this case, I'm pretty sure it's time to replace that pair of New Balance shoes: they're probably well over their mileage limit by now – in future I'll vary the shoes I use for each type of run so that I can recognize more easily when they are worn out.

My next decision is whether to buy another similar pair, or to try a different brand. I have run with Saucony, Brookes and New Balance as my main running shoes for years now: while it's tempting to change it's also tempting to stay with the same brand. I'll make that decision and buy a new pair from Road Runner Sports while their sale is still on – if you need running shoes, now is the time to get them!