Interval Workout

Interval training is a great way to torch calories and improve your fitness level, but you don't need to be beholden to your stopwatch when doing speed work. You can add a dash of play to your sprints with a fartlek workout. Fartlek is the Swedish term for speed play, which just means changing your speed for varying distances while out on a run. How could a word that sounds so silly not be fun to put into practice?

This variation of interval training is perfect for urban areas since you can use different landmarks — like bus stops, benches, or the length of a city block — to set the distance of your sprints. Pick a spot ahead of you and increase your speed as you run toward it. Simple no? Keep reading for a sample workout after the break.

Trying to get rid of a stubborn tummy pooch? Interval training is proven to blast belly fat.

Here's a 45-minute interval workout you can do on the treadmill (set the incline to one to prevent shin splints) or head outdoors and use one of these running apps on your iPhone to keep track of your speed. Or you can use the RPE column on the right to determine how fast you should be going. You'll end up burning 317 calories while toning your tush and thighs. If this workout is a cinch or way too difficult, just adjust the speed to fit your level. See the workout after the break.

I know many runners and cyclists, who though tempted by the lure of mixing it up in a triathlon, ultimately skip these races because they're intimidated by the swim. Not only is swimming in open water scary, unlike running, it is also considered a skill sport, similar to tennis or golf because technique is so important. If you feel less than confident in the pool, taking lessons to hone your stroke is helpful; I did it and learned so much. Do know that long sessions of laps might not necessarily be the best way to train. Many tri coaches recommend sprint interval training in the pool to challenge your speed, before tiring and losing your hard earned technique.

Here's a workout I have been doing lately. It is mostly freestyle, but I like to add a little backstroke to work the opposing muscles.

Check out the workout.

I'll admit, intervals on a treadmill are convenient. The clock is right there for timing, and you can easily adjust the pace with a push of a button. But nothing beats an outdoor workout in my book. Plus it's excuse-proof; you have to make it back to your starting point — no hopping off the treadmill and calling it quits.

Similarly, running at one pace can get a little dull, even when the birds are singing, so add some speed work into your running routine.

Here's a fartlek (no snickering, it's Swedish for speed play) workout compliments of Equinox trainer Lauren Fairbanks. She's been around the track a few times and knows the drill. Lauren calls this workout the three-two-one and if you keep reading, you will find out why.

By now, we all hopefully know that interval training rocks. Whether you're running, rowing, or swimming, playing with speed has multiple benefits. One way to push the interval envelope is to decrease the amount of rest time between your bouts of sprinting. By shortening your recovery time, you're pushing your anaerobic threshold and strengthening your cardiovascular system. Plus it's fun to mix it up once in a while.

My latest elliptical workout is 30 minutes of calorie-burning interval fun. Keep reading to check it out.

A short workout is better than nothing at all and squeezing in any kind of fitness is certainly part of my holiday survival plan. This 30-minute treadmill workout definitely gets the job done. Using intervals, the half an hour workout burns calories and revs up the metabolism.

To check out the workout, just read more

*Calories burned calculations are based on a 130-pound woman