There are a million reasons why you don't have time to work out this weekend. And there's one reason why we don't buy it. With a little creativity, you can easily complete a total-body workout in just 15 minutes—no weights or machines required.

If your kid's soccer (tennis, baseball, etc.) tournament sucks up the time you'd usually spend at the gym, here's a simple solution: Don't just stand on the sidelines while they devour orange slices during half time. Jog over to the playground or an open grassy area and try these challenging bodyweight exercises from trainer Craig Ballantyne, C.S.C.S. "You'll be surprised how hard you can work without a gym," he says.

Alternate between the Y squat and the Spider-Man pushup for three sets of each. Then perform the remaining three exercises consecutively (again, without rest), doing three sets of each. By the time the final whistle blows, you'll have completed a muscle-building workout without missing a single kick.

Get Fit in 15 Minutes: Download the Use Your Body as a Barbell Workout and three other 15-minute workouts to your MP3 player


1. Y Squat
Stand with your shoulder blades pulled back and your arms extended up and out so your body forms a Y. With your feet slightly more than shoulder-width apart, sit back at your hips to lower your body. Go as low as possible without allowing your back to round. Squeeze your glutes and push yourself back up to the starting position. Do 12 repetitions.

2. Spider-Man Pushup
Assume the classic pushup position with your legs straight and your abs tight. As you lower your body, bend your right leg and rotate your right knee outward until it's outside your right elbow. Don't drag your foot, and try not to allow your torso to rotate. Return to the starting position and repeat, pulling your left knee to your left elbow. Do eight reps per side.

3. Wall Slide
Stand with your butt, upper back, and head against a wall. Raise your arms so your shoulders, elbows, and wrists also touch the wall. Maintaining these points of contact, bend your arms until your elbows are tucked in at your sides. You should feel a contraction in your shoulders and the muscles between your shoulder blades. Reverse the move. Do 10 reps. No wall around? Just imagine it. The purpose pf the wall is to make sure you bring your arms far back enough. It's not crucial for the exercise.

4. Single-Leg Romanian Deadlift
Stand on your left foot with your right foot raised behind you, arms hanging down in front of you. Keeping a natural arch in your spine, push your hips back and lower your hands and upper body. Squeeze your glutes and press your heel into the floor to return to an upright position. Perform eight reps per leg.

5. Spider-Man Lunge
Assume the classic pushup position with your hands directly beneath your shoulders, your legs straight, and your abs braced. Lift your right foot off the floor, bending your knee, and place the foot outside your right hand. Return to the starting position and lunge out with your left leg. Continue alternating legs for a total of 20 reps.