After finishing the cycling portion of a standard triathlon, only 6.2 miles (10 kilometers) stand between you and the finish line. Exhausted, you hop off your bike, grab a quick drink and change shoes to run the remainder of the race on foot. Will your months of training pay off?

Though it takes dedication and endurance to finish a triathlon -- a race consisting of swimming, cycling and running segments -- there seems to be no single path to success. Some triathletes prefer to train solely outside, while others supplement exercising inside, too.

Ideally, the best training for a triathlon would consist of swimming, cycling and running in conditions similar to the ones triathlete would experience in a race. But when freezing weather or sweltering heat persists, it might be a good idea to hop on the treadmill to avoid a potentially dangerous workout outside. Treadmills can be useful tools if used correctly in a workout regimen.

In addition to providing an opportunity to train while stuck indoors, short training sessions on a treadmill can improve your running speed in a triathlon by allowing runners to create inclines that simulate hills while maintaining a consistent, faster pace. Many treadmills also provide heart monitors that can help the runner keep track of his progress.

Ultimately, triathlon coaches agree that it's not a matter of whether a triathlete should use a treadmill, but how he uses it. For triathlon training specifically, longer workouts are not as effective as speed training, which should be performed in manageable intervals. While altering factors such as incline and speed, short sets performed on treadmills can keep your neuromuscular system healthy, help boost blood lactate threshold rates (the ability to maintain an intense activity) and improve leg strength [source: Bernhardt]. The level of control treadmills provide makes them a valuable workout tool year-round -- even in combination with outdoor training.

Treadmills may have their benefits in triathlon running, but are there any disadvantages? Find out on the next page.