Cycling shoes required for spinning?

I usually wear my Shimanos when I go to a spinning class, but lately I've been running to my gym (about 2.5 miles) doing some upper body weights and THEN getting on the spin bike. I still have my running shoes on for this, and I usually just strap them in. (I can't wear tri shoes because I pronate - the Asics Gel Kayano shoes are indispensible for my runs). It doesn't feel bad, besides me feeling like a dork when everyone else has cycling shoes on.

Is there anything technically wrong or potentially damaging about spinning in running shoes?

Lots of folks do it. On of the gyms where I taught actually didn't have clipless pedals. I HATED IT and brough in my own pedals.

Here are a couple of observations from me:

No matter how tight you tighten the toe cage, you still probably can't utilize/strengthen your hamstrings glutes as much as you can with clipless pedals.

Most running shoes have a very soft sole -- not optimal for cycling (power transfer) and some folks experience burning/discomfort in the soles of their feet from the soft sole.

If you participate in classes where you stand frequently, you may experience some pain in your toes or balls of your feet.

Most toe cages are pretty one-size-fits-most. This means that you might not achieve optimal positioning of your foot on the pedal (or your knee over the pedal spindle).

Velogirl, thanks for the insight.
I guess I never really noticed because after a run, I usually spin at a smaller gear than usual. Less available fuel.
Now that I think about it, I am usually parked at the front of the class if I spin-only, I sit at the back of the class when I run/spin.

Joy

is key. Make sure your the widest part of your foot is over the widest part of the pedal. If you experience fatigue in your feet while standing, sit down. If you have a high arch you will be more susceptible to plantar fasciitis. Any pain in the arch or heel could indicate you are not getting enough support in your arches. don't ignore these indicators. you're smart to work on your spinning as heavy climbing can be stressful on the plantar as well. good luck. s