Running Economy - Is There Something With Them?

We had to control shoe 100g heavier pair and another pair that was 300g heavier per shoe as well. And then we did see that afterwards when we looked at the data that indeed with the heavier shoe they were running slower. So it worked really well sort of confirming again if you have shoes on your feet you don't always have good sensation of how every day are. But most people sort of after two or three of times we did that picked up and was like wait a minute there's something with these shoes because why do I need to take them off all the time.