If your training shoes are older than six months, there’s a good chance they’re silently wrecking your body from bottom to top.

Sure, they might look okay. The soles aren’t entirely worn out, the fabric isn’t torn, and they still feel comfortable enough. However, the problem is that shoes break down internally long before they show signs of wear on the outside.

If you’ve been dealing with sore Achilles, aching knees, tight hips, lower back pain, or even shoulder stiffness, your worn-out shoes could be the hidden cause.

Most people don’t think twice about replacing their shoes. Still, they spend hundreds on chiropractors, physios, and other treatments without anyone asking about the one thing supporting them all day—their shoes.

Wearing old shoes can cause hidden damage. Every time you jump, run, or lift during your workouts, your shoes absorb impact. Over time, the cushioning and support inside the shoe break down, even if the shoe looks fine from the outside. The midsole—the part that absorbs shock—compresses and stops working, meaning your joints take more impact with every step.

This is even worse for CrossFit and HIIT-style training. These workouts involve constant movement, jumping, cutting, and impact, so the breakdown happens faster than with casual wear.

And what happens when your shoes aren’t doing their job anymore?

Your body compensates.

Your Achilles starts screaming, your knees ache, your lower back gets tight, and you might even feel it in your shoulders from your body adjusting to poor foot support.

It should be no hidden secret that I HATE allied health professionals, particularly the ones we are dealing with down here. But I also believe that you can very quickly fix most issues yourself and that prevention is better than the shit cures most professionals give.

So I say, Instead of spending $90+ on chiropractors, physios, massage therapists, and every other professional trying to fix what feels like an unexplainable ache, try this first:

Treat yourself to a new pair of shoes.

A solid pair of training shoes costs about the same as two or three physio visits, but the difference they make can save you months of pain.

So, how often should you replace your shoes? Every 4-6 months is a competent and confident rule of thumb for CrossFit and HIIT-style workouts. Training might be closer to every 3-4 months if you train daily.

If you’ve been training in the same shoes for over six months and you’re feeling aches and pains that don’t seem to have a clear cause, switch them out and see what happens.

Your body might just thank you for the investment.