Compound Exercises vs Isolation: How to Make the Right Choice

Compound exercises vs isolation

Here is one of the biggest questions around physical activity that pops up every now and then: should you stick to compound exercises or isolation exercises as a part of your training schedule?  Is one better than the other?  If compound lifts are so good  – how come there are so many gyms that offer a huge variety of expensive machines targeting specific muscles?

The truth is – both methods can be used to improve strength.  Both methods can be used to build a better body.  But there are scenarios where one would work better than the other.

Instead of taking sides, in this article we will explore advantages and disadvantages of both compound and isolation exercise and then try to boil everything down to a simple routine that utilizes the best elements from both camps.

Benefits of compound exercises

Compound exercises save time.  Most of us have busy days and very few people can dedicate more than one hour a day to structured exercise activities – and even that is often challenging enough.  If you want your muscles to get stronger or bigger, you need to stimulate them with enough weight and enough time under load.  Having to face external time limitations, you would either significantly reduce the amount of time spent on each muscle group, cramming too much into one session, or only exercise a limited number of muscle groups – which means that, by the date you go through all muscle groups and complete full cycle, the interval between exercise sessions targeting the same muscle group would be too long.  Both solutions put you at a disadvantage because they do not provide enough of a stimulus for your muscles to develop.  By contrast, compound lifts compress the time needed to exercise several muscle groups by incorporating everything into one multi-joint movement.  This allows you to do one lift per session, targeting several muscle groups at the same time, and design a cycle that involves only three to four different compound lifts – not only shortening the time for each session, but also shortening the interval between the days you target the same muscle group.

Compound exercises are best for developing strength.   Physical strength is often defined by dictionaries as the power to move heavy weights.  However, physical strength can manifest itself in many ways – and not all of them involve moving heavy weights.  For instance, the ability to hang off a pull up bar for a long time does not involve moving weights – but it is the grip strength that gives you that ability.  Doing planks doesn’t result in the floor or your body moving – but it’s the strength of your core that determines whether you can do this or not.   From that perspective, a better definition of strength might be – the power to resist and counteract a load.   The loads our bodies experience and have to counteract in daily scenarios typically involve synergistic work of several groups of muscles.  And truly heavy weights can only be moved when the power generated by multiple muscle groups gets combined and amplified.  You probably wouldn’t call someone who can lift a 56-pound kettlebell by flexing only one finger strong overall (although that would be a freakishly strong forearm) if the same person cannot do a moderately heavy single-bodyweight bench press.  People we call strong usually demonstrate that strength through different compound pushing, pulling and carrying movements – never through exhibiting individual strong muscles.  And the way you develop that combined strength is through compound exercises that target a combination of muscle groups.  When multiple muscle groups come together in a multi-joint movement, the weight involved (and, thus, the subjective indicator of strength) can be increased significantly.   Exercising with heavy weights stimulates your muscles better than exercising with light weights, triggering adaptations in central nervous system and muscle fibers that ultimately improve the ability of the same muscles to move heavier weights – hence the increase in strength.

Barbell compound lifts promote proper form and are actually less injury-prone.   Although many people think that exercise machines are “safer”, compared to big scary barbells that can crush you under their weight – this is very far from truth most of the time.  Sure, when you ignore safety measures, disregard technique, rush your progress and overestimate your abilities – barbells can be unforgiving.  Whereas you can get sloppy with an exercise machine and, after your muscles give up, drop the cable machine weight onto the stack or let some lever return the its original position with a slam – with a barbell, you would most likely need to make sure the weight is right for your level, the form is correct and the movement is precise.  This is not to say that you cannot do them wrong – of course you can – but you will know much faster that this is the case, when you do.  A lot of compound exercises require you to position the free weight (barbell, in most cases) along the center of balance – and true progress can only be achieved when you correct your form.  For most of these compound exercises, correct form and technique is the only way you can move heavy weights.  If your form is wrong, the exercise will feel very awkward or you will be pulled out of balance and will not be able to properly complete the lift – so you will be forced to either stick with lower weight or correct your form.  In effect – and to an extent – heavy barbell compound lifts are self-correcting.  With exercise machines, however – their perceived “safety”, insufficient core recruitment, awkward fixed angles and levers that do not take individual limb length in consideration and other factors allow you to ignore these indicators and let you continue, potentially damaging your joints and ligaments.  Worst of all – any potential progress with exercise machines has little carryover effect to daily activities or free weight lifts.

Compound exercises are the best exercise for weight loss. Well, not really weight loss – but fat loss (which is what the vast majority of people really want).  Muscles need energy to work and to recover – and if you exercise right, the demand for energy during recovery will continue for a long time after you complete your session (up to 72 hours, depending on intensity).  Naturally, the larger the muscles involved – the more fuel they need during and post-exercise.   Isolation exercises target smaller groups of muscles and, therefore, their metabolic effect is much lower, compared to compound exercises involving big multi-joint movements.  The energy for your muscles comes from several sources (listed in the order they are used up) – phosphocreatine, glucose, glycogen (a storage form of glucose within the muscle tissue or the liver) and stored body fat.  Intense heavy barbell compound lifts significantly increase your muscle’s metabolic activity and demand for energy – so, while your immediate energy demands during the exercise would probably be largely covered by glucose and glycogen, post-exercise rebalancing and recovery would require a lot of “slower-burning” but much more energy efficient fat.

Disadvantages of barbell compound lifts

There aren’t many disadvantages to list – in fact, if you absolutely have to choose, compound lifts should always be your first choice because they give you better health benefits and generally promote a more balanced development – provided that you are healthy and able to perform them.  Some of the few relatively obvious scenarios where compound exercise may not work as well are listed below.

Compound lifts cannot be used as physiotherapy and recovery from trauma.  People recovering from severe trauma, weeks of bedrest or something of this sort typically need very small, controlled and isolated loads.  This is best achieved by isolation exercises precisely targeting specific muscles.

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Compound exercises do not work if you have temporary or permanent lack of mobility.  Broken limbs do not always mean you should stop exercising (in fact, there is a lot of benefit in continuing your workouts on a smaller and less intense scale) – but they would most probably put your compound exercises on hold for a while.

By nature, most barbell compound lifts require spotting and/or special equipment.  One of the benefits of major barbell compound lifts comes from the weight used – it has to be heavy!  But it is difficult to push you limits when there is a safety risk.  If you attempt to squat with a very heavy barbell without a proper squat rack with safety pins or try to bench press without the same safety pins or experienced spotter(s) – the bar can pin you down if your muscles fail.  Typically this is not the case with isolation exercises that use smaller weights or exercise machines.

Benefits of isolation exercises

Does all this mean isolation exercises have to be completely disregarded?  Not necessarily – they actually may have their time and place, depending on your goals, and in some cases they may even be preferred.  Listed below are some of the key benefits of isolation exercise.

Certain muscles can only be targeted by isolation exercises.  With all of the benefits of barbell compound lifts, certain smaller muscles can only be meaningfully targeted through isolation exercise – typically this concerns muscles that do not change length appreciably during the lift.  Instead, they tense in a “locked” position to stabilize the weight and add more power to the lift through irradiation of muscular effort (it is a phenomenon whereby you can increase the power output of a given muscle by also recruiting nearby muscles) – and that is why whole body tension is important when performing heavy-weight compound lifts.  While this can still contribute to their strength – that strength might be limited to the specific position they are used in (i.e. – these muscles would get better at the same stabilization job, but not necessarily stronger overall throughout the full range of motion).  In cases like that – adding targeted isolation exercise into the mix may be beneficial.

With that being said – make sure you read the point below regarding hypertrophy, which also covers the role of compound lifts in developing smaller muscles.

Isolation exercises may be best for hypertrophy.  If you are after bigger muscles (such as if you are training using bodybuilding protocols) – isolation may be a better choice.  One of the key elements in achieving bigger muscle size is time under intense load.  When you perform heavy compound lifts, the time you spend under load is naturally limited – precisely because the weights are so heavy – and isolation may help you increase this time under load and trigger better hypertrophy.

That being said, remember that even the smallest muscles get involved in compound lifts when those lifts get heavy and challenging – those that do not directly participate in the lift may act as stabilizers.  And while such stabilizer muscles may not change length – eccentric / concentric movements are not the only way to stimulate muscle growth.  When a muscle tenses without contracting (to stabilize the weight or balance) it is experiencing isometric loads.  While isometric exercise may not be enough to make the muscle noticeably stronger for the overall lift (most research shows that strength developed by isometric exercise is specific to the position the muscle is being trained in and may not carry over well if you change the angle at which you train it), it makes it stronger in that specific position (give or take 5 degrees or so).  Most importantly, the muscle still experiences the stress necessary to trigger adaptive response and development.

Not convinced?  Look at gymnasts as an example.  They hardly spend a lot of time doing isolated heavy bicep curls – but their arms are typically very well developed.  That hypertrophy is often a result of isometric loads experienced in positions when the arms are fully extended (hanging off the Olympic rings or pull up bars, handstands, etc.) or close to it.

Still, when you are looking for that professional bodybuilder look and need to target the most underutilized small muscles – or when the muscles in question need an additional boost because they are your weak point for whatever reason and hinder your overall compound lift – isolation may be the way to go.

Isolation exercise is easier to perform when you don’t have access to proper equipment.  If you are limited in your budget, space or anything else – your only choice might be isolation exercise.  If you are traveling to locations that do not have a well-equipped gym readily available – it’s relatively easy to pack a few resistance bands.  If you live in an apartment and can only exercise at home, it’s much easier to add a few heavy dumbbells than build a full-size squatting rack.  This may not give you the most bang for your buck, but it is undoubtedly better than doing nothing.

Disadvantages of isolation exercises

Lack of carry-over.  Because most isolation exercises (especially those performed on machines) do not fully recruit the same group of muscles as a compound lift would, it is difficult to apply the skills learned to bigger, heavier lifts (or even to typical everyday scenarios that require strength and agility).

Form may suffer when isolation exercises are performed with machines.   Many exercise machines – especially the “budget” versions – are hard or impossible to adjust to accommodate various individualities related to limb lengths and related movement paths.  Imagine (as an extreme and fictional example) a bicep curl machine where, no matter how you adjust it, the rotation axis of the cam to which the handles are attached never fully aligns with your elbows – in order to perform the exercise, you would be forced to compensate by bending your wrists, flaring or otherwise repositioning your elbows, etc. – often right in the middle of the movement – creating awkward angles, creating strain and potentially increasing wear and tear on your connective tissue in the long run (given that isolation work typically involves higher number of reps and sets).

Isolation exercise is very time consuming.  Although this is hard to explain to young teenagers who want to have an impressive biceps (because it is so apparently visible), balanced muscular development should really be your goal – you can’t limit your exercise to only a few popular muscles.  But if you had to exercise all muscles in somewhat isolated fashion, the amount of time needed to complete a full cycle involving all major muscles would be enormous.  That is why many bodybuilders often spend hours in the gym – and even then are able to exercise only a part of their body, leaving other parts to other days, when exercise sessions take equally as long.

Choosing between compound and isolation exercises

The best thing, however, is that you don’t really have to choose between the two types of exercise.  Instead, try to following approach:

  • Build your core program around heavy barbell compound exercises, such as deadlift, squat, bench press and overhead press. This will allow you to build enough strength to handle heavier weights – whether in compound or isolated movements.  It will also trigger the best metabolic response to keep your body fat percentage in check.
  • When you start working with really heavy weights for your main compound lifts, chances are – you are not going to be able to complete more than 3-5 reps in 3-5 sets (if you can do more – your weight is not heavy enough). This may not provide enough time under load for your muscle to develop in size (although strength-wise you will have no problem).  So, for your “finisher” move, preferably within the same session (or separately, if time does not permit) – incorporate a few quality isolation exercises targeting the same muscles.  This will increase time under load and provide additional stimulus for your muscles, keep you from being bored by introducing some variety to your routines and also train the same muscles at different angles, different intensities and using different forces, which is going to contribute to their all-round development.
  • Adjust the time allocated to each of these two types of exercise in accordance with your current goals. For instance, some people prefer to do more isolation training when preparing for the beach season (again, because it may better assist in sculpting your muscles in a certain way), some others may be training to reach a specific strength goal, disregarding specific aesthetic goals.  Whatever approach you choose – just don’t forget to still spend enough time under a heavy bar no matter what.
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Simple exercise routine for the best of both worlds

So, with all that considered, is it possible to get both strong and visibly muscular and leaner in less time, with no imbalances and no detrimental impact on health?  Yes it is – and this is what the sample exercises below are trying to achieve.

It is a simple routine that you can follow to get both strong and good-looking.  The program is based on three training days per week, with each day covering one major compound lift and two or three “assistance” exercises that are complementary to the main lift and isolate the same muscles as those used in the main lift. You can, just as easily, adjust it to any number of training days per week, although doing more than four should be reserved to only very serious competitive athletes and freaks of nature who can recover exceptionally well.

Main lifts. The sequence in which you perform these compound lifts throughout your week doesn’t matter – just make sure that you have enough time to recover between the days on which you are doing the same major lift.  This is specific to your age, experience, overall fitness level and many other factors – so play it by ear.  Lack of consistent progress may be a good indicator that you are not allowing sufficient recovery time.  A good rule of thumb is to have at least 1-2 days between exercise sessions when you are starting out (with about a week between the same lift) and at least 2-3 days between exercise sessions as you progress and start working with heavier weights (heavier loads require more time to recover), stretching the interval between the same lift to about 1.5 weeks.

Always perform compound barbell lifts first (as you need to be fresh to perform them) and only then move on to lighter-weight assistance work using isolation exercises.

Isolation exercises. Keep in mind that such additional isolation exercises performed on the same day as the main lift are optional, but beneficial when you not only want to improve strength, but also want to get the aesthetic benefits, as this approach will trigger better hypertrophy in addition to strength.  This is NOT a targeted bodybuilding approach, but rather a balanced program that gives you the best of both worlds – better strength and better looks.

Isolation exercises should be performed with no more than 50% of the weight used for your best set of the day – you would be loading muscles that will be already significantly fatigued by the main lift.  Isolation work should be performed slowly (especially in the eccentric part of the move) – go for 1-2 seconds per concentric (when the muscle contracts and moves the weight) and 3-4 seconds per eccentric phase (when the muscle lengthens again and returns the weight to the original position).

The first number in parenthesis represents the number of working sets (excluding a few warm-up sets), while the second number represents the number of repetitions.

The weight used is expressed as a percentage of your 1RM (1-rep maximum), which should be re-tested about once a month – with the increase in your 1RM, the absolute weight used in your training will increase as well.

Day 1

Main lift: Deadlift (1 x 5) @ 75% + (1 x 5) @ 80% + (1 x 5) @ 85%

Isolation exercise 1: Bent row (5 x 8) @40% of peak main lift

Isolation exercise 2: Machine hamstring curl (4 x 7) @35% of peak main lift

Isolation exercise 3: Dumbbell or barbell shrugs (barbell shrugs are best performed with a hex bar) (5 x 8) @ 50% of main lift

Day 2

Main lift: Bench press (1 x 5) @ 75% + (1 x 5) @ 80% + (1 x 5) @ 85%

Isolation exercise 1: Triceps cable pushdown (5 x 8) @35% of peak main lift

Isolation exercise 2: Dumbbell bench press (4 x 7) @50% of peak main lift

Isolation exercise 3: Weighted dips (4 x 7) @40% of peak main lift

Day 3

Main lift: Squat (1 x 5) @ 75% + (1 x 5) @ 80% + (1 x 5) @ 85%

Isolation exercise 1: Machine leg press (5 x 8) @50% of peak main lift

Isolation exercise 2: Kettlebell swing (5 x 10) @40% of peak main lift (or with the heaviest kettlebell you can find and work with)

Isolation exercise 3: Weighted back raise (5 x 8) @ 25% of peak main lift

Day 4

Main lift: Overhead press (1 x 5) @ 75% + (1 x 5) @ 80% + (1 x 5) @ 85%

Isolation exercise 1: Dumbbell lateral raise (5 x 8) @35% of peak main lift

Isolation exercise 2: Weighted push-ups (5 x 8) @ 35% of peak main lift

Isolation exercise 3: Kettlebell clean and press (5 x 8) @ 35% of peak main lift  (or with the heaviest kettlebell you can find and work with)

Final important notes

  • Do not overanalyze the routine above. It is not perfect – and it is not trying to be.  There are several ways to achieve strength and hypertrophy goals – some would work better for one group of people, some would work better for the other group.  This set of exercises is only a generic sample – you will be able to build your own routines as you get more experienced;
  • There are many ways you can structure your workout – drop sets, pyramids, ladders, heavy singles, supersets, high reps, low reps, fast reps, slow reps – enough to make your head spin. Do not overcomplicate things.  The routine above is not meant to be your bible – it is merely food for thought in gaining some experience and designing your own, utilizing the same principles.
  • The key principle for the routine above is always the same: you add accessory exercises to your main lift for the day trying to load the same muscles in a different way. From that perspective, you can use this routine “as is”, or scrap it completely and, instead, add accessory work (with an emphasis of doing lighter-weight-higher-rep isolated exercise) to established and effective powerlifting-centered routines, such as 5-3-1 discussed previously, StrongLifts 5×5, or any similar low-rep heavy-weight routines.
  • You will feel sore! Even more sore than you would if you only did low-rep heavy weight work.  While this is normal and expected – it also means you might need to add an extra day to your recovery (and some extra sleep time).
  • Most importantly – have fun! If you have a bit of experience in the gym, you can easily substitute isolated accessory exercises presented above with something similar.  It’s OK to change things up every now and then – as long as you stick to the principles (heavy powerlifting-style lifts for the main portion of your daily routine and light-to-moderate-weight isolation exercises as accessory work).