Take your GPS watch or bike computer. Change it from miles, pace per mile, and miles per hour to kilometer, pace per km, and kilometers per hour.
Bike and run while pretending that it’s really showing you miles and miles per hour.
My workouts yesterday were a blazing fast hour long run at 6:32 pace, and an hour long ride in triple digit temps at an average speed of 23.9!
Unfortunately, this doesn’t work for swimming, because we (we = Americans) tend to measure in yards, which are shorter than meters. You win this one, metric system!! Maybe use some fins and paddles?
Seriously, what good is tri training if you’re not having any fun?
P.S. My apologies to my friends already using the metric system. But, if you want to feel super-slow for a day, please do the reverse of the directions posted above.