One of the biggest mistakes people make when designing their workouts is to divide the body up into parts and train one muscle group at a time. This is called isolation training and it leaves a lot to be desired.
Instead, concentrating your workouts around compound, multi-joint exercises will give you back significantly more than the effort invested so that you reach multiple goals at once: greater strength, muscle, performance, and a healthier, leaner body.
To further convince you, this article will go into detail about the differences between compound and isolation training and give you seven valuable benefits of compound training.
Difference Between Compound & Isolation Exercises
Compound exercises are also known as multi-joint exercises because they recruit the muscles around more than one joint at a time. For example, squats recruit muscles around the hip (glutes, abs, lower back), knee (quads, hamstrings), and to a lesser extent, the ankle.
An overhead press recruits muscles in the shoulder joint (deltoids, upper back), elbow (biceps, triceps), and to a lesser degree, the abs, glutes, and lower back. Other examples of compound exercises are deadlifts, step-ups, lunges, presses, pulls, Olympic lifts, and jumps.
In contrast, isolation exercises are those that only use one joint at a time, such as biceps curls (elbow joint), triceps (elbow), or knee extensions (knee joint). It’s not that there’s never a time to train single-joint exercises, but rather that multi-joint lifts should make up the majority of your workout if you want to get the biggest bang for your effort. Plan workouts around squats, deads, pulls, and presses and leave the small muscle group exercises to round out your training.
Reason #1: Burn More Calories
The more muscle you train at once, the greater the energy cost for the body. Naturally, this makes multi-joint exercises your go-to training mode when you want to lose body fat.
For example, a study that tested the metabolic cost of different exercises found that compound exercises, which were classified as “large” muscle mass exercises, required 11.5 calories per minute compared to only 6.8 calories a minute for “small” muscle mass exercises. Researchers conclude that anyone who is concerned with fat loss or weight maintenance will have greater success by prioritizing compound lifts to maximize energy expenditure.
Reason #2: Greater Functional Carryover To Sports & Daily Life
You could argue that the coolest thing about compound exercises is that they have a high transfer effect both for sports and daily life activities. This makes them ideal for everyone: athletes, body composition trainees, weekend warriors, and older individuals training to maintain fitness, etc.
Compared to isolation lifts, compound exercises require a much more complex neurological organization, which is to say that they teach the muscles to efficiently coordinate the firing of motor units responsible for powerful muscle contractions. The result is that training them can improve strength, balance, and your ability to move efficiently.
For athletes, this means increased ability to exert force into the ground for a quicker first step and greater jump height. For everyone else, it means greater functional capacity and less pain for an overall better quality of life. Say goodbye to aching knees as you go up the stairs or shoulder pain as you put away groceries overhead!
Reason #3: Save Time
Large muscle group, multi-joint exercises raise the potential for producing a more time-effiicient training session. One large muscle mass exercise, such as a deadlift or power clean, can exercise as many muscle groups as four to eight small muscle group isolation lifts.
The obvious result is that planning your training around compound exercises and then tacking on a few single-joint exercises at the end for pre-hab and structural balance is a major benefit when the most common reason people give for not exercising is lack of time.
The other benefit of training compound lifts is that you can get cardiovascular benefits (see #6) without having to do additional conditioning, and you hit the whole body in one training session, reducing the number of workouts you need to do per week. If you’re training one or two body parts per workout, you’ll need to train almost every day to achieve a frequency threshold that produces significant strength and muscle development.
Reason #4: Use Greater Training Loads For Faster Adaptations
This may be obvious, but it’s worth reinforcing the fact that because compound exercises recruit more muscles per lift, you can handle much heavier loads than with single-joint exercises. Just consider the amount you can lift for bench press versus bicep curls or deadlifts versus calf raises. In some cases, the difference will be hundreds of pounds, which will pay off in terms of greater overload and faster physique and performance adaptations.
Reason #5: Better Bone Strength
Many multi-joint exercises like squats, overhead press, and deadlifts load the spine, which will increase bone mineral density and prevent fracture and osteoporosis. This may not seem like a top concern for you if you’re in your twenties, but the reality is that everyone needs to start banking bone as early as possible.
With the rise of obesity and sedentariness, bone problems are increasing and the simple act of training with compound exercises has been found to radically improve bone strength. For example, a 2012 case study measured bone density in two women (age 48 and 54) who were competitive female powerliters. They trained almost entirely multi-joint exercises with at least 70 percent of their lifts as heavy as possible and had bone density scores well above average for women ages 20 to 29 who are considered to be at the peak of bone mineral density.
Reason #6: Provide A Cardiovascular Training Benefit
The purpose of cardiovascular exercise is to improve the ability of the heart to function as a pump and deliver oxygenated blood to organs and working muscle. Many people think this can only be accomplished through typical “cardio” activities such as running or biking, but the truth is that any exercise that raises your heart rate and uses a significant amount of muscle will do the trick.
Although lifting weights is anaerobic (not using oxygen), once you put the weight down and recover between sets, the aerobic system takes over, delivering oxygen to the muscles and brain and removing byproducts that limit performance.
The catch is that to achieve measureable improvements in cardiovascular function your exercises need to require a high level of perceived exertion, which is best achieved with large muscle group exercises, a high volume, and heavier loads. Seated knee extensions or triceps kickbacks won’t do the trick. Also bear in mind that for conditioning benefits, short rest periods are necessary.
Reason #7: Improve Flexibility
Most people hear “flexibility” and think of static stretching. Although holding a muscle in a lengthened position can increase range of motion around the joint, it requires a LOT of time and repetition (stretches need to be held for 30 seconds and repeated daily). Another drawback is that stretching reduces neural drive to the muscle, reducing power—not something you want to do pre-workout.
Good news is that compound movements that contain an eccentric component are more effective at increasing lasting flexibility than stretching. The eccentric motion occurs when your muscle lengthens. For most exercises it happens when you lower the weight, such as the “down” motion of the squat, deadlift, or bench press. Research shows that exercises that emphasize the eccentric motion by lengthening the time spent on the down motion leads to growth in the individual muscle fibers, lengthening the muscle for the long-term. For example, to increase flexibility around the hip joint, take 4 to 6 seconds to lower yourself down in the squat and then come up to vertical in one second.
Final Words: Although there’s a time and place for isolation training (it’s great for promoting structural balance in a commonly weak muscle like the VMO of the quadriceps, or prehabbing a complicated joint like the shoulder girdle), designing your workouts around multi-joint exercises will give you more bang for your buck. You can train strength, cardio, body composition, and flexibility all in one short but sweet session a few times a week.