“When a measure becomes a target, it ceases to become a good measure.” – Goodhart’s Law
This concept, largely discussed in the world of economics, applies quite well to running and fitness in general.
Most of us probably have “indicator” workouts. These are workouts we do that give us some indication of how we can do in an upcoming race.
These workouts can be very helpful if you train for the race and then use the workout as an indicator of fitness. However, what if you train for the workout?
Probably the most famous of these indicator workouts would be Yasso 800s. This workout worked very well for Bart Yasso. However, how well should we expect 800 meter repeats to really work as a predictor of marathon fitness?
Well, if you convince yourself that you want to run a certain time in the marathon, then focus on getting your times for 800 meter repeats down to the level that suggests that’s possible, I hope you can see the issue. You’ll be well trained for a 5K but, if you slack on your long runs and tempo runs to get these workouts in, how do you think your marathon is going to go?
This may be an extreme example but it’s true of any kind of indicator workout. Train for the workout and you’ll do the workout very well but how much will that help you run a better race? Focus on training for the race because that’s what matters most.