I am currently obsessed with Fartleek intervals; they provide a great interval workout, but since they are unstructured you don't have to constantly look at your watch.
An "interval workout" is basically just a workout that alternates between low and high intensity training. Traditional interval workouts are very detailed. They are based on prescribed, time based bouts of work. These structured, time based workouts can be intimidating, especially for newbie exercisers, and frankly they often aren't that much fun. Sometimes when I do traditional intervals I spend so much energy looking at my watch stressing over the time that I forget to enjoy my workout. I hate that!
Fartlek intervals are unstructured, and therefore more accessible, especially for newbie exercisers. Plus, Fartlek intervals can literally be done anywhere, so you have no excuse to skip your workout. Use any indoor cardio machine, or do them while you walk, run, bike, roller blade or even swim.
To try Fartlek intervals start by warming up for ten minutes. On an indoor cardio machine pick a random goal. Sprint until the chorus in the song you are listening to, or until your favorite character speaks on the TV show you are watching. Outside, pick a random landmark to sprint towards. Any landmark will do, try a stop sign or crosswalk. If you are swimming, sprint to the end of the pool or pick a number of strokes to sprint for. Once you hit your landmark, the end of the pool, of your predetermined point in the song or TV show, slow down and recover. Repeat for ten to thirty minutes. Finish with a cool down and then stretch.
When I train with a friend, I lovedoing partner Fartlek intervals. Try them running or biking outside or on any indoor machine. Just make sure the machines you use are next to each other so you can communicate. Start by warming up for ten minutes. For the main body of the workout the partners take turns being the trainer and saying "go." If you are outside, sprint toward a destination of the trainer's choice. Inside, speed up on your machine for however long the trainer decides. The trainer can make the workout as hard or as easy as they want by changing how often and how long the intervals will be.
The point of interval training is to introduce the body to more intense work, the goal being that eventually the more intense effort will become the body's new "norm."
My favourite analogy is the feeling of city versus highway driving. After driving on the highway, city driving feels slow. Your perception of a normal speed has changed. The intent of interval training is for your "highway intensity" to become your new "city intensity." Basically, intervals help you become more fit! So, lace up your running shoes and give Fartleks a try. Let me know what you think!