7 Adrenaline-Boosting Workouts

1. 3-Mile Challenge

Boost your strength and endurance with this fast-paced workout from Craig Ballantyne, C.S.C.S.

How it works: Crank out as many pushups as you can. Then, resting a minute between exercises, do one set each of chinups and dips, completing your maximum number of repetitions for each exercise. Now go for a 3-mile run. Record the number of reps you were able to perform and your run time. Retest yourself each month.

2. Hoops Fat Blaster

Sculpt your body on the court, says Alan Stein, C.S.C.S.

1. Sit at one baseline and hold a basketball in front of your chest. Stand up and sit down without letting your arms, hands, or the ball touch the floor. Repeat 10 times, then sprint to the other baseline.
2. Assume a pushup position, but with one hand on the ball. Perform a pushup, then roll the ball to the other hand and repeat. That's 1 rep. Aim for 10, and then sprint back to the other baseline.
3. Hold the top of a pushup on the ball for 1 minute. Rest 30 seconds. Repeat the entire sequence 4 to 6 times.

3. Muscle Express

Use your bicycle as a barbell to build your upper body.

Pedal hard for 2 minutes in a high gear. Then hop off the bike, flip it, and grab it by the frame. From this position, you can train your back, arms, and shoulders, using the bike as resistance. For example, perform 10 reps of single-arm bent-over rows, arm curls, or front raises. Then ride for another 2 minutes. Continue this pattern of lifting and riding until you've completed each exercise 3 to 5 times.

4. High-Speed Rope Circuit

Alternate between jumping rope and doing strength exercises to build a leaner body.

1. Skip rope 20 seconds.
2. Do 8 walking lunges forward, then turn around and lunge back to the starting position.
3. Skip rope 20 seconds.
4. Do as many pushups as you can (to failure).
5. Skip rope 20 seconds.
6. Do pullups to failure.

That's one round. Complete 4 to 6 rounds, adding 10 seconds to your rope-skipping time each round.

5. Rock-Hard Abs

This 3-day-a-week plan is fast yet brutal, says trainer Juan Carlos Santana, C.S.C.S.

Lie faceup on the floor with your arms and legs straight, in an X. Lift your arms and legs 8 inches off the floor, toes pointed out. This is the starting position.

1. With your right arm, reach up toward the ceiling, then lower to the starting position. Repeat with your left arm. Do 5 reps.
2. Raise your left leg above your hip and reach toward the ceiling with your foot, then lower back down. Repeat with your right leg. Do 5 reps.
3. Do 1 and 2 simultaneously with opposite limbs. Perform 5 reps.