With 30 Minutes to Spare, How Do You Exercise?

Thirty minutes may be an adequate workout for the casual gym-goer striving to stay in shape. But for a competitive athlete in training, anything under a few hours is woefully inadequate.

Or so you thought.

Christi Masi is a Seattle-based King County health educator, personal trainer and endurance athlete who frequently travels to compete in multiday adventure races. She understands the toll a busy schedule can take on training routines. The trick, she says, is to maximize whatever time you have with high-intensity bursts of cardio along with effective, core-building workouts.

Follow her intense plan of weaving interval training with circuit training, and 30 minutes will suddenly feel more like 90.

Tabata and Fartlek
They might sound funny, but you won't be laughing after using these high-intensity interval-training systems. Both workouts increase aerobic capacity through short bursts of intense cardio activity — such as running, biking, jumping rope, swimming or working on an elliptical trainer — and core-building exercises.

To do a Tabata, choose an exercise and go as hard as you can — 100 percent maximum intensity — for 20 seconds, rest for 10 seconds and repeat seven more times (you'll need to use the timer on your smartphone to stay on track).

Fartlek, which means "speed play" in Swedish, is more free-form: The athlete varies the speed at her own pace, pushing herself as hard as she can for a period and then slowing down when she tires.

Masi says Fartlek is perfect for outdoor workouts. "You pick an obstacle, like a bench, and sprint for it," she says. "Once you reach it, slow your pace for a breather, spot another obstacle and sprint for that."

Use Tabata and Fartlek workouts with any of the following single exercises or throughout a circuit to get maximum fitness in a short amount of time.

Stairs
If you're in a hilly city, run out the hotel door to the nearest steep hill and do repeats. Or, go to your hotel stairway — three flights are more than enough — and run up and walk down.

Burpees
Also called squat thrusts, burpees are four-step, full-body exercises that deliver an intense workout in a short period. Start in a standing position, drop to a squat with hands on the floor, thrust your feet behind you as if doing a pushup, and quickly jump back to a standing position with your arms above your head. "You'll tire fast with these," Masi says, "but the key is to keep going."

Core building and toning
You probably can't do burpees for 30 minutes, so add box jumps, pushups, planks and side planks to your circuit. "You don't need any equipment for these workouts, so if you're really short on time, do them in your hotel room using Tabatas," Masi suggests.

Hit the pavement
Even for 30 minutes, running at a fast pace is an efficient way to maintain cardio, burn calories and clear your head. "It's also an awesome way to see the city and find restaurants and coffee shops you want to try," Masi says. She suggests using a smartphone app like WalkJogRun or MapMyRun to track your course.