Just like you, but different
If you don’t want to read the link, and why would you, then essentially there are two thoughts in this.
Unless you could turn it on and off, I suppose, so for a brief moment be all zippy and then back to normal. Useful for running in sports perhaps, only of course if you could actually go the distance, so for me perhaps the 100 meter sprint might be the thing. I’m note sure, even though it’s my own super-power, if you can dial it up and down, so only just a bit a faster to win a race, but not so fast that you ‘wink out’ of viability and re-appear at the end of the race.
I did also think of the calorific requirements of going fast might do, but I don’t think this is an issue, you’d just be you with fast legs, or perhaps as you normal speed legs, but just really fast to everyone else. It is just a thought.
Problematically, even in my thoughts, you’d have to slow the planet and then everything everywhere in infinity because otherwise it would appear odd to the outside world if it was a local effect. Right?
Both of these come back again to what reason you might want to use this, and generally it might be again money, or sex, but could be fame or notoriety it brings.
For the ‘ I go faster’ option you might not be able to go faster than a computer, and so trying to take advantage of electronic transactions wouldn’t be an option, but you might become brilliant at games like ‘Snap’
For the slowing down thing you’d never drop a cup or glass again, a financial saving.