Impressive is the backyard mechanic who, with nothing but spare parts and a rusty wrench, takes a car that has seen better days and transforms it into an eye-catching roadster over the course of a weekend or two. How does he do it? He knows ways to manipulate the tools at his disposal to mimic the high-end machinery found in world-class body shops.

When it comes to building your physique, you may run into a similar scenario. What if you train at home, without all the accoutrements found at a well-equipped gym? Do the same as that mechanic: Use the tools you do have (dumbbells, barbell and an adjustable bench) to turn gym-specific machine moves into ultra-effective home exercises. . You’ll never leave home again!

Pulldown to Front
Target: Back

If your home is equipped with a chin-up bar, that’s the obvious substitute for the pulldown. Those of us who don’t have one hanging around need to get more creative with the back. Although the angle of attack isn’t the same, the Two-Hand Bent-Over Dumbbell Row works well in place of pulldowns. Perform this the same as you would a bent-over barbell row, except with dumbbells. You can hold the weight hammer-grip style, or use an overhand grip to mimic the barbell version. You can always find a great power rack that will allow you do some of these exercises without taking up too much space or costing a fortune.

Unique Variation: Barbell Pullover
Lie on a flat bench, barbell in your hands. At the start, bend your elbows to lower the bar close to your forehead; maintain that elbow bend throughout the move. Lower the barbell back behind your head and the bench until you’ve achieved a good stretch and the weight is inches from the floor, then lift the bar back up and over your face until it reaches your chest.

Key Point: To maintain emphasis on the back muscles, keep your elbows bent throughout the movement.

Seated Cable Row
Target: Back

The easy switch is the One-Arm Dumbbell Row. Keep your back flat and watch your form on this move; if you can’t move the dumbbell without body english, lighten the load.

Unique Variation: T-Bar Row
Brace one end of a barbell in a corner of the room, and load weight to the end that extends into the room. Straddle the barbell with a shoulder-width stance, then reach down and grasp the bar with a hand-next-to-hand baseball-bat grip. Keep your knees bent, back flat and chest up as you pull the weight upward toward your chest. Squeeze your shoulder blades back at the top of the movement, then slowly lower the bar downward. Don’t allow the weight to touch down between reps.

Key Point: Periodically switch the grip so that your left hand is on top during some sets and your right hand is on top for other sets.

Standing Calf Raise
Target: Calves

A good option is the Standing Single-Leg Calf Raise. Hold a dumbbell in one hand as you perform reps on the edge of a step or similar platform. With your free hand, hold a vertical support beam or wall for balance. Switch hands each set.

Unique Variation: Donkey Calf Raise
Find a staircase and stand on the first or second step. Bend over and put your hands against the step directly in front of you. Your back should be flat, your legs almost completely straight, and the balls of your feet at the edge of the step. Slowly lower your heels toward the floor, then flex both calves to lift upward.

Key Point: For added effectiveness, have someone sit across your lower back and hips (carefully). This will add resistance and, surprisingly, some balance to the exercise. When you fatigue, the person can dismount and you can perform a few extra reps for a drop set.

Pec-Deck Machine
Target: Pectorals

The clear alternative is Dumbbell Flye, which involves the same movement you perform on a pec deck, only lying on your back instead of sitting up. Visualize “creating a circle” or “hugging a tree” with your arms to help promote proper form.

Unique Variation: Wide-to-Narrow Decline Push-Up
Get on the floor in standard push-up position, then place your feet on an elevated, secure surface such as a bench or set of stairs. Starting with a wide grip (about 4-8 inches outside shoulder width), perform a push-up, extending your arms fully and lowering your body to a point where your chest is about an inch from the floor. After that initial set of wide push-ups, narrow your grip and repeat.

Key Point: Continue to move your hands closer together with each successive set until you have completed a full range of wide and narrow push-ups.

Cable Pressdown
Target: Triceps

The Bench Dip is a great replacement; place your hands on a flat bench and your feet up on a chair, and perform the dip motion. For added resistance, have someone place a weight plate on your lap. As you fatigue, you can lose the plate and continue as if performing a drop set.

Unique Variation: Dumbbell Skullcrusher
Hold two dumbbells with a hammer grip and lie faceup on a flat bench. Position your upper arms beside your head and extend your arms straight up over your chest. Lower the weight by bending your elbows to bring the dumbbells back toward the top of your head, then reverse the motion to return to the start position.

Key Point: If you don’t have a spotter, you can perform this exercise one arm at a time and spot yourself with the nonworking arm.

Leg-Extension Machine
Target: Quads

When in doubt, innovate. The One-Leg Seated Dumbbell Extension uses a dumbbell in place of the machine. Sit on a bench with your knees hanging over the edge. Place a dumbbell across the ankle of the working foot, keep your toes flexed upward, and extend your lower leg upward until your knee joint is straight. Then lower to the start and repeat for reps.

Unique Variation: Weighted Sissy Squat
Stand sideways, hold onto a door frame or other stable object with one hand, and hold a weight plate to your chest with the other hand. Take a very narrow stance and rise up onto your toes. Keeping your chest out and back tight, bend backward at the knees to lower your body toward the floor. Keep your chest pointed toward the ceiling and stay up on your toes. Return to the start by flexing your quads to bring your torso back upright.

Key Point: To ensure balanced development, alternate which arm holds the weight. Also, never allow your heels to touch the floor.

Lying Leg-Curl Machine
Target: Hamstrings

Try the Lying Dumbbell Leg Curl. Lie facedown on a flat bench, hold a dumbbell between your feet and perform a leg curl. The additional balance needed calls more stabilizer muscles into play – so you get the best bang for your buck.

Unique Variation: Dumbbell Single-Leg Romanian Deadlift
Stand with a dumbbell in each hand, feet shoulder-width apart. Step forward with one foot 6-12 inches. Keeping your head and chest up, back flat and front leg straight but not locked, bend over at the hips. Focus on the front leg on the way down – your back leg is simply for balance. Lower the dumbbells alongside the front leg; when they reach mid-shin, reverse the motion, concentrating on flexing the hamstring of the front leg.

Key Point: Repeat all reps on the working leg before alternating. Use straps if necessary.

Leg-Press Machine
Target: Quads

While barbell squats would be ideal, many home gyms don’t have a power rack, which you need to do these safely. However, if you have a good set of straps to handle heavy weights, a Dumbbell Squat will do the trick.

Unique Variation: Wall Sit
Place your back against a wall, and slide down until your thighs are parallel to the floor. Keep your feet flat on the floor and back flush with the wall, and hold that position for 10-15 seconds. Increase that time as you get stronger. You can spot yourself by pushing on your thighs.

Key Point: For added resistance, hold dumbbells, flat ends resting on each upper quad.