It's offered to your attention the cosmonaut shoes to use them onboard MIR Soviet space station. The shoes may be worn while wearing Penguin muscle training suit, or as underwear for Orlan EVA space suit. The shoes are made of natural leather and have zipper on the top. So, they are quite comfortable to wear. Because of the above there are several incomparable advantages:

The photo on the left shows Orlan-DMA space suit for EVA. Beside it you can see the water-cooling underwear costume to prevent cosmonaut from overheating by the sun in outer space. You can see the "space shoes" put onto the mannequin together with the water-cooling costume. Click on the photo to enlarge it.

If you take a look at the right photo you will also see the "space shoes" to be worn together with Penguin suit used by the cosmonauts for muscle training when in orbit. Penguin has rubber parts in it, so, a cosmonaut overcomes its resistance when wearing it, in other words, Penguin makes cosmonaut's body to train muscles when he moves in it. Enlarge photo for better view.