Messy winter weather can make track workouts and other types of speedwork difficult to do consistently and safely. Not so for fartlek workouts. Swedish for "speed play," fartlek training is an unstructured form of speedwork where you vary your pace from fast bursts of running to easy jogging. Because fartlek training is a free-form activity that can be done just about anywhere, it's the perfect type of speedwork for winter.

To maintain your speed during the cold-weather months, do one fartlek workout every week. Try any of these three workouts, or use them as the basis to make up your own. Keep in mind that the fartlek segments are run hard, but not all-out.

Fastest Marathon Runners

With this workout, use landmarks to dictate the length of your faster and slower segments. Once you've warmed up, look ahead and pick an object-maybe the next telephone pole or tree. Run faster until you reach that landmark, then immediately pick another object up ahead about the same distance away and jog to it. Start with three to five fartlek segments and add one or two per week.

Nutrition - Weight Loss

Add an extra strength component to your winter fartleks by running them on inclines. Short hills, overpasses, inclines in parking garages, and ramps in stadiums all work well. Begin with inclines that are about 50 steps in length. As you go up the incline, gradually increase your turnover and speed. Walk or jog down. Start with two or three incline repeats and add one more each week until you can run eight.

Run for time

You can do this type of fartlek workout anywhere since your watch is your guide. After your warmup, run faster segments of one minute, two minutes, or three minutes. Alternate the fast segments with easy jogging or brisk walking for the same amount of time as your fartlek segment. Start with three to five fartlek segments and add one or two per week.