The WOD program consists of four strength workouts per week with three days of muscle recovery. This recovery time is an opportunity to include more cardio in your daily routine.
For optimal fitness, consider easy running, hiking, or walking in your daily routine with a goal of 2-5 hours per week. If it works for you, you can spread the time over the entire week. Make it fun, something you'll look forward to doing.
In addition, you might include one session per week of running. For example, run as hard as you can for 20 seconds and rest 10 seconds. Repeat this cycle 8 times, for a total of 4 minutes. You'll be amazed at how effective this high-intensity, short duration workout is on your overall conditioning.
If you're just starting to sprint for the first time since you were a kid and 20 seconds proves too taxing, cut the interval, say to 10 seconds or 6 seconds, and rest by walking the same distance that you sprint.
What's important to remember is to run all out and have fun doing it. Be a kid again.