Video: See how to build your own triathlon at the gym.
The Multisport Tri
This cardio workout provides all the benefits of a real triathlon, but since you're not actually competing, you'll do the swim last, when it's convenient. No pool? Use a rowing machine instead.
How to do it: Pedal a bike at a steady, comfortable pace—an effort level of 5 or 6 on a scale of 1 to 10—for 10 minutes. Hop down and run outside or on a treadmill for 10 minutes at an effort level of 5 or 6. Finally, head to the pool or rowing machine and do another 10 minutes at the same intensity.
Mix it up: Short on time? Cut the final leg in half and increase your intensity to 8.
The User-Friendly Tri
You can complete this cardio workout in one section of your gym and still challenge your cardiovascular system in new ways.
How to do it: Choose any three cardio machines, such as an elliptical trainer, a treadmill, and a stationary bike. On the first machine, do 10 minutes at an effort level of 5 or 6. Move to the next machine and complete 10 minutes at an effort level of 9 or 10. Finally, do 10 minutes on your last machine at an effort level of 5 or 6.
Mix it up: Change the order of the machines each time you train, so the hardest (middle) segment always provides a new challenge.
The Speed-and-Power Tri
This cardio workout builds speed, power, and lower-body strength.
How to do it: Choose any three cardio machines that allow you to adjust the resistance or gradient, such as a treadmill, bike, or stairclimber. Warm up for 2 minutes at an effort level of 5. Step up your effort to maximum for 30 seconds by increasing the machine's resistance level and/or incline while maintaining the same cadence. Return to the warmup effort level. That's one interval. Do three intervals, then move to the next two machines and do three intervals on each.
Mix it up: Instead of raising the incline or resistance during your 30-second bouts, pick up the cadence of your maximum effort.
The More-Muscle Tri
This workout mixes strength training with aerobic work for greater strength and less fat.
How to do it: Jump rope for 30 seconds, rest for 30 seconds, and repeat five times. Then perform a total-body workout consisting of basic body-weight moves, such as squats, pushups, stepups, chinups, and crunches. Do one set of each, without rest. Finish with a 10-minute jog at a medium pace.
Mix it up: Swap the calisthenics for a dumbbell circuit. For more routines, check out the 15-Minute Workout: Ground Force and Right Moves.