In a recent issue of Runner's World magazine, a marathoner discussed how she would reward herself for her training runs. She paid herself $1 for every mile she ran, and all the money she "earned" by running, she would spend on a shopping spree in San Francisco the day after the run.
Now, anyone who has trained for a marathon can see how the money would start to add up fairly quickly, with scheduled training runs of distances between 5 and 20 miles (plus the great bonus for the 26.2 mile marathon).
It would definitely put a dent in the budget, that's for sure. But not a bad way to convince yourself to go out and do that 15 mile training run. That's $15 more that you can spend later!
Of course, this idea is nothing new. Lots of people reward themselves for fitness related pursuits by planning purchases around certain goals. Offices have The Biggest Loser competitions where someone walks away with a cash reward for losing the most weight.
I think there are a lot of great ways to "incentivize" yourself to become more fit using money. Say you set a goal of running 50 miles a month. You could just set aside $50 in your budget, and if you run all the miles, you get to spend the $50, and if you only run 49 miles, you get nothing. The problem there is that around mile 35, you realize that there just aren't enough days left in the month to get in another 15 miles so you just give up. Instead, you could follow what the above mentioned marathoner did and give yourself $1 per mile.
Or you could take it to the next level. You want to run 50 miles this month so you set aside $50. For every mile you run, you "get" $1. But at the end of the month, whatever is left gets donated to charity. Of course, donating to charity is a good thing, so it's not like you lose, even if you only run half of your planned miles one month. But it's less money for you to put towards that new pair of shoes you've been eyeing.
This doesn't have to be limited to things involving miles. Make it your goal to workout 20 times. Or 25 times. And reward yourself accordingly.
It might be just what you need to get you to run that extra mile.