Next time you're looking to get the most out of your cardio workout, try this mini triathlon (boredom buster) at the gym.
Swim: Hop in the Pool for 15 minutes of lap swimming. (If your gym does not have a pool, supplement with the rowing machine).
Bike: Dry off and hop on a stationary bike for 15 minutes of cycling.
Run: Immediately head over to the treadmill for a 15 minute run.
As always be sure to warm-up and cool-down for at least 5 minutes each. In the beginning, just aim at getting it done. Once you get used to it, either increase your time (20 minutes instead of 15) or aim to increase your workload in the 15 minutes (run two miles instead of 1.5).
Let me know what you think, but most of all, enjoy!