Isolation Exercises: Do you need them?

Isolation exercises, like the bicep curl, tricep kickback, or leg extension are often a staple in many peoples training programs.  Often an entire day in your training schedule is allotted to just isolation exercises, think arm day.

And while getting an amazing pump swells your arms and makes you feel great, is it an efficient use of your training time?  Taking it a step further, is it even needed? 

If you cut out isolation exercises entirely, and instead used your training time more efficiently by focusing only on compound lifts, would your results suffer?

The answer to that is no, according to a recent study conducted by Brazilian sports scientists and published in the November edition of MDPI Sports. 

The Study

The researchers took women who had been lifting for over a year and divided them into two groups. 

The first group trained 6 days per week doing only compound, multi joint exercises.

The second group did the same as the first group, but also added single joint isolation exercises to their training sessions. 

The duration of training was 8 weeks. Before and after the study the researchers measured the participants strength as well as body composition. 

The base program of multi joint, compound exercises that each participant followed is shown below. At the bottom of the diagram you will see the additional isolation exercises performed by the second group marked with an asterisk.

 Results

The inclusion of the single joint isolation exercises added no benefit to the study participants.

For example, the athletes in the multi joint plus single joint isolation group performed bicep curls as well as tricep extensions while the multi joint compound only group did not, however both groups experienced the same increases in strength as well as muscle mass.’

Simply put, both groups made the same gains even though one group performed more volume via isolation/ single joint exercises. 

To Quote the Researchers

To quote the research team “ Based on the present findings, we conclude that the use of single joint exercises as a compliment to a resistance training program containing multi joint exercises brings no additional benefit to trained women in the terms of muscular performance and anthropometry” (the scientific study of the measurements and proportions of the human body)

Further the state “In light of this, we suggest that the use of a resistance training program containing only multi joint exercises might be recommended with the purpose to provide a time efficient approach with no impairment in strength, endurance, or anthropometric measurements”.

Digging Deeper

This study was performed on women, so it is fair to wonder if the same effects would carry over to male subjects.  Because muscle and strength are built in the same manner, regardless of sex, the results of this study are likely to be the same if performed on male subjects.

The volume of isolation exercises.  Only one single joint, isolation exercise was added per training session, so it is possible that increasing the volume and adding multiple isolation exercises per training session could provide adequate stimulus for additional gains. 

It could also be true, however, that simply increasing the volume of multi joint, compound exercises to match the proposed increase in single joint isolation exercise would provide the same benefit to the muscles being isolated, while also benefiting the adjoining muscles which are engaged during the compound lift. 

The Take-Home 

This study shows that adding single joint, isolation exercises to a routine comprised of multi joint, compound exercises provides no benefit. 

This is especially profound when you realize that these single joint exercises were added to the routine increasing total volume and time under tension.

One study may not be enough to jettison isolation training entirely, (although many athletes so just that and don’t miss a beat) however this study reinforces the fact that the foundation of any good training program is compound, multi joint exercises.  

There are many examples of this, not only in theory, but in practice.  Gymnasts, for example, do not lift weights at all.  Their entire strength and conditioning programs revolve around progressive calisthenics, that is using their own bodies for resistance while performing various multi joint, compound movements. No single joint isolation movements at all.  

Many gymnasts possess physiques that are the equivalent of high level fitness competitors.

The bottom line is, at best, compound isolation exercises are all you need to get the best possible results out of your training, and at worst, they are the efficient foundational element that is responsible for the majority of the gains that an athlete makes. 

Focus on progressive, multi joint, compound lifts in your training.  If you do add isolation exercises, be sure that they do not come at the expense of multi joint movements. 

 Your strength and your physique will thank you for it.