Someone was asking us about the bag we use to randomize our workouts. As a runner himself, this person was asking how we keep our runs (specifically) dynamic.
Within the bag that we randomly select daily workouts from, there are mostly runs. In order to diversify our runs and to keep improving our performance, there are a variety of runs in the bag.
For instance, there are a couple shorter "speed" runs – 4 mile routes where we go as fast as we can. There are three "endurance" runs in the bag – longer runs (one is 12-miles) that take us on a variety of routes. There's a "sprint" run, during which we alternate between running fast and slow. You get the idea.
Today we picked the "stamina" run. It's a moderate distance, but the kicker is that we have to run up what we call "throw up hill" twice as part of the run. The hill is about a mile long stretch that – when we started this – we could only make it up once. With practice, we're able to crank it out twice and we don't even feel like ralphing at the top anymore.
Keep your exercise varied. It'll keep you engaged, and it will keep your performance improving.
Mix things up. It keeps life interesting. –Phil Dendro