In the exercise world, there is often fierce debate over protocol, application and technique. At its most productive this debate can spur on experimentation, enabling us to refine the application of exercise protocol. Sometimes we need to question elements of the protocol that have been ingrained in HIT since its inception or since the time of its initial popularity in the 70s and 80s: the original Nautilus era. In this post I want to discuss a research paper that does just that, one that I have been meaning to write about for a while.
Researchers James Fisher, Luke Carlson, James Steele and Dave Smith set out to test the validity of pre-exhaustion theory along with the impact of exercise order and rest intervals in their 2014 paper: The effects of pre-exhaustion, exercise order, and rest intervals in a full-body resistance training intervention.
The theory of pre-exhaustion
The theory of pre-exhaustion technique works on this premise: that to best stimulate the prime mover of a compound (multiple joint) exercise, it is necessary to perform an isolation (single joint) exercise for that muscle group prior to the compound. For example, perform a pullover for the latissimus dorsi before performing a pulldown.
Arthur Jones suggested pre-exhaustion was necessary due to the weakest muscles being the limiting factor at the point of MMF (momentary muscular failure) in a compound exercise e.g. the forearms and/or biceps in a pulldown. The aim of preceding the compound exercise with an isolation exercise is to “pre-exhaust” the prime mover of the compound. Jones also suggested that the trainee minimize any delay in moving from the isolation exercise to the compound for best results.
The research methodology
The researchers split the research participants into three groups: the Pre-Exhaustion (PE) group, the Pre-Exhaustion with Rest (PER) group, and the control (CON) group. All groups performed each exercise in their routine for a single set to MMF.
|Groups||Order of exercises||Rest||Exercises|
|PE||Isolation then compound||≤5s rest between pre-exhaust pairings
120s between each compound to isolation
60s between the last three
|PER||Isolation then compound||60s across the board||Same exercise order as above|
|CON||Prioritizing compound||60s across the board||
In the Pre-Exhaustion group, the first six exercises of the routine form the actual pre-exhaust pairings consisting of pec fly then chest press, leg extension then leg press, pullover then pulldown. Rest between each pre-exhaustion isolation exercise and its following compound was kept to 5 seconds or less. This can be considered an accurate and traditional interpretation of pre-exhaust. The routine was then rounded out with abdominal flexion and lumbar extension exercises. A longer rest period of 120 seconds was taken between each pre-exhaust pairing, then a rest period of 60 seconds between the last three exercises.
The Pre-Exhaustion with Rest group performed the same exercises in the same order as the pre-exhaust group except they took 60 seconds rest, between each and every exercise.
The Control group used the same exercises but in a different order to the other two groups. This group performed all the compound exercises first in the routine, and then all isolation exercises, they also took 60 seconds rest between each exercise throughout.
What the research found
The results of the study showed large and significant increases in strength for all three groups and for all exercises performed. This suggests that neither use of the pre-exhaustion technique, nor order of exercises in the routines performed, or rest periods between exercises affect strength gains.
What does this mean for us?
We don’t have to rush from an isolation exercise to a compound exercise to get strengthening benefits from either of the exercises. And let’s face it unless you happen to have a Nautilus double machine, keeping rest periods between two exercises to single digit seconds is usually highly impractical.
Does this mean that we can’t continue to use pre-exhaust if we enjoy doing so? No of course not: the pre-exhaust group made strength gains comparable to the other two groups. If you enjoy doing pre-exhaust you can certainly continue to do so.
What it does mean is that we have yet another piece of research that reinforces the freedom that we can allow ourselves in structuring our own routines and those of our clients.
Factors that do affect exercise sequence
- Any rehab or prehab needs
- Necessity of keeping the trunk musculature fresh in certain circumstances (e.g. a barbell bent over row needs to be performed before any lumbar specific exercise)
- Structuring the order to minimize the load required for certain exercises (e.g. if you can stack the leg press, you may want to perform hip extension or hip abduction prior to the leg press)
- The equipment you have available to you
- Layout of the gym
- The intention of the specific workout
- Personal preference
- Variety in exercise order for the sake of variety/altering the stimulus
A general guide for exercise sequence
There is no ideal one size fits all order for sequencing the body parts trained in a workout, nor for the relative positioning of isolation and compound exercises. Here is an order I sometimes employ which you could use as a starting template for full body routines:
- Upper arms
- Hips and Legs
- Rotator cuffs
Remember that you may have valid reasons for altering this order for yourself or when working with a client- individual needs and requirements need to be considered a priority.
Rest intervals between exercises
Effectively you can take as little or as much time as you prefer between exercises. Personally I like about 60 seconds “rest” between exercises. This gives me time to note down salient data about the previous exercise, set up the equipment for the next one, take a sip of water if needed, get into position, mentally prep to start the next exercise… and to do all this in a calm manner. I have many of my clients take a similar rest period, but beginners get much longer (due to the practicalities of coaching/teaching and conditioning) as does anyone else who needs longer.
REX Conference 2015
Two of the authors of the research paper referenced in this post, will be speaking at a forthcoming exercise event in Minnesota. Both James Fisher and Luke Carlson will be delivering keynote speeches at this year’s REX Conference (formerly known as HIT Resurgence).
The theme for the conference is The Science and Application of Strength Training for Health and Human Performance and is being held on April 10 and 11, 2015 at the IDS Conference Center in Minneapolis.
I had the pleasure of talking with Luke and here is his message to HITuni’s followers:
We are delighted to announce all REX Conference attendees will be eligible for a special discount on the HITuni online certification courses (you must attend the REX Conference 2015 in person, where you will get an exclusive discount voucher code for use on HITuni.com).
Learn more about the REX Conference 2015 and purchase your tickets here: REX Conference 2015