No matter how cramped your schedule or room is, Calgary-based exercise physiologist Michael Bracko bets you'll have 15 minutes before breakfast and dinner and a few square feet of personal space on your next business trip. The good news: That's all you need to stay in shape. A University of New Hampshire study published in February's Journal of Strength and Conditioning Research found that over the course of 12 weeks, people exercising for 15 minutes twice daily had significantly better improvements in aerobic fitness, blood pressure, and VO2 max than those completing one 30-minute session per day. And with the following Bracko-devised 15-minute, full-body travel regimen, you could squeeze a workout into your walk-in closet.

Complete exercises consecutively for one minute each without rest, then rest one minute and repeat.

[1] SUITCASE SQUAT
Hold a suitcase (not so heavy it affects form) tucked against your chest and stand with legs slightly wider than shoulder width apart. Squat to 90 degrees. Repeat.

[2] FRONT PLANK
Lying facedown with your upper body resting on bent elbows (shoulder width apart) and fingers interlocked on the floor, raise your hips so you're in a rigid push-up position on your forearms and toes. Hold for one minute. If you can't maintain form, complete mini-sets within the minute: 15 seconds up, five seconds rest.

[3] SIDE PLANK
Same as front plank but on your side. Lying on your left side, raise hips to make a rigid plank braced by the sides of your feet and left forearm, which should be directly beneath your shoulder. Hold for one minute (or for mini-sets). Switch sides and repeat.

[4] NARROW PUSH-UP
With your index fingers and thumbs touching so they form a triangle beneath your chest, execute push-ups. (An August 2005 study in The Journal of Strength and Conditioning Research found that narrow push-ups fired the most muscles, as compared with regular or wide hand placements.)

[5] STEP-UP
Stand, facing a chair, and step up with your right leg, then your left. Then down with left, and then down with right. Begin with your left leg on the next rep. Try an armchair without its seat cushion instead of a desk chair to get the ideal height of 12 to 16 inches.

Bird Dog (Illustration by Jonathan Carlson)