Home Blog CP Internship Blog: Can Circuit Training Develop Work Capacity? – Part 2

CP Internship Blog: Can Circuit Training Develop Work Capacity? – Part 2

Written on April 28, 2010 at 9:15 am, by Eric Cressey

This guest blog comes from current Cressey Performance intern, Sam Leahey.

Last time, we discussed circuit training and the validity of whether or not it develops “mental toughness” in our athletes.  We then questioned whether this “mental toughness” (however one defines that term) is actually translating into enhanced sports performance. This week’s article focuses on the implications regarding circuit training and “work capacity”.

Simply type the term “work capacity” into YouTube and you’ll end up with tons of videos implementing a wide variety of exercises in circuit training fashion, most which consist of modified strongman events, and every one of these claims the same thing: “it develops work capacity.”  What does that even mean?

Now, enter “work capacity” into the search bar on a peer-reviewed research journal site (PubMed, etc.) and what are the findings? Nearly every study listed with the term “work capacity” in the title is in direct reference to something specific like “physical work capacity,” “anaerobic work capacity,” “aerobic work capacity,” “wingate test work capacity,” “upper body work capacity”, “cardio-respiratory work capacity,” or “functional work capacity.”

Compare and contrast these two discoveries and we are left with the simple conclusion that “work capacity” is specific and using it as a general term is scientifically unjustifiable.  In fact, it is pretty much theory altogether unless directly tied to something else. Yet, when looking across the landscape of private training facilities and collegiate Strength & Conditioning settings, we find that most coaches and trainers use the term “work capacity” in the aforementioned grossly-oversimplified way as opposed to a specific type of capacity that actually makes transferable sense. I often wonder why that is?


There are many common arguments in favor of the work capacity idea. Coaches and trainers are now more than ever espousing and raising “work capacity” awareness.  Let us look at some of the underlying principles and theories behind the “work capacity school of thought” and try to make sense of it and establish how coaches arrived at the solution of “in order to develop work capacity we need to do circuit training”. This will lead into the conclusion of this article.

Principle: Work capacity is developed when the human body tolerates and recovers from a workload. Once adapted to that stimulus they need to be able to work above that “work threshold” for continued success.

I can’t believe how much this gets parroted these days. When I think about this statement I am left wondering how this is any different from regular strength training or even a stinkin’ bicep curl? It sounds to me like just another way to describe the Principle of Overload, not the “principle of work capacity”! Furthermore, I wonder how it’s indicative of the conclusion so many people reach: “I have to do circuit training to develop work capacity?”

Theory: If an athlete’s general fitness or capacity is low, their specific fitness or capacity will not improve.

So you’re saying if I take a highly deconditioned athlete with no general fitness and make him play soccer for one week straight he won’t be a better, more conditioned soccer player by day seven than he was on day one because his “general fitness/capacity” was low to begin with? Really?


One more time. . .

Theory: If an athlete’s general fitness or capacity is low their specific fitness or capacity will not improve.

Though still a vague statement perhaps, now we’re getting closer to something actually definable – “general fitness.” Many coaches use the terms “general fitness” and “work capacity” synonymously. Perhaps this is where coaches arrive at the conclusion of “I should do circuit training to develop general fitness.”

More importantly, though, do I even want “general fitness” for my? Or, just specific fitness? It seems we need a definition or list of components of “general fitness” before we can answer that question. You might say that the progression should go from general to specific and my response there would be general WHAT and specific WHAT? What quality are we talking about – strength, power, flexibility, speed, or something else? I feel that to simply just say we should go from general to specific may be shortsighted; we need to clarify what quality we’re covering.

If you do an internet search or academic search to define “general fitness,” you most often times end up at the same thing that is still taught in academic settings today – “General Fitness consists of the 5 Health Related Components of Fitness,” which are:

  • Muscular Strength
  • Muscular Endurance
  • Cardiovascular Endurance
  • Flexibility
  • Body Composition

Once here, we can actually begin to clarify the argument.  Am I supposed to develop all these above qualities optimally to attain “general fitness”? Do I even need or want some of these above qualities to be maxed out in say, a sprinter? Nope.

If we’re talking about Muscular Strength then I totally accept the idea of general strength to specific strength.  However, if we’re discussing cardiovascular endurance, then I think most of us would disagree with the general-to-specific thought process. Both Charlie Francis and Mike Boyle have obliterated this general-to-specific idea with regards to energy systems years ago. They speak against doing “general running” (aerobic jogging) and then moving into “specific running” (anaerobic sprinting).

Francis has written about how kids need to do enough power related activity in their teen years to really reach optimal performance in sprinting when they get older. What is he saying by that? He’s saying we should start specific and end even more specific.


Mike Boyle took Francis’ thoughts and began doing tempo runs in early off-season with his athletes to develop a sprinting base, which is still inherently specific, and then progress them to higher intensity sprints. Basically, he started specific in as broad a way as he could and then got even more specific with the training. He did not attempt to develop an aerobic base first by running miles and then gradually move to sprinting; rather, he started the off-season with higher volumes of lower intensity “sprints” (tempo runs) and then moved to lower volumes of higher intensity “sprints” (shuttle runs). A different way Coach Boyle also approached this idea during his career of building proper sprinting work capacity (notice it’s specific and not “general”) is represented in this graphic:


Though a different order of intensity and volume, all I’m trying to get you to see is the point that it is not developing “general fitness,” but instead specific fitness. So, hopefully now we can all see that the general to specific idea doesn’t hold up too well until we clarify what quality we’re referencing (strength, flexibility, energy systems, or something else).

Theory: Work capacity enhances and coordinates the cardiovascular, metabolic, and nervous systems and it is composed of 2 components:

1) The ability to tolerate a high workload by recovering quickly from the stimulus so that another stimulus can be presented on a consistent basis.

2) Being able to resist fatigue no matter what the source.

These two points taken alone, I struggle to see how people are lead to the conclusion that they need to be implementing circuit training to develop this so called “work capacity.” However, taken all together with the initial mention of the physiological systems, we may have finally arrived at a specific qualitative point – the nervous, cardiovascular, and “metabolic” systems.

Somehow coaches take this to mean that doing circuit training is the best option for coordinating and enhancing these systems. If I take time in my program to do circuit training, will it coordinate and enhance my nervous system optimally with all that fatigue going on during the circuit, especially compared to what I else could be doing instead to prepare my nervous system? I would say “no;” circuit training does not fit the bill optimally.

If I take time out of my conditioning program to do circuit training, will it coordinate and enhance my cardiovascular system better than what I’m already doing? Again I would have to answer “no.”

Will circuit training enhance and coordinate my energy systems (metabolic system) better than my conditioning program? Nope.

The point here is the traditional methods you’re already using in your strength training, power training, and conditioning program are far superior in developing those physiological systems than doing circuit training.

Here’s another definition being thrown around the internet:

“Work capacity refers to the general ability of the whole body as a machine to produce work of different intensity and duration using the appropriate energy systems of the body.”

This is probably the best attempt at defining “work capacity.” Yet, the question still arises: do I need or want this “general ability” of my body to “produce work” of varying intensities and times? Instead, how about narrowing it down to what specific energy systems I’m going to need to compete in my sport or event and at what intensity or durations? Doesn’t that make more sense that just saying to somebody, “Hey, I’ve got good work capacity because I can do a million sit-ups, a 1RM squat, a bunch of pull-ups, and then sprint 50 yards – all in under 5 minutes!” Does a competitive sprinter benefit from being able to run a marathon, do a ton of pushups, then do a ton of pull-ups, when he’s competing in a 55 meter dash? Would a golfer optimally benefit from doing random “general fitness” activities at random intensities and durations as opposed to specific fitness activities?


So, I humbly ask: why are we doing circuit training to develop general work capacity? How did we ever arrive at the conclusion that a general work capacity was needed as opposed to a specific work capacity like linear sprinting or multiple changes of direction or vertical jumping or asymmetrical rotation (golfer/pitcher)?

Instead, can I suggest we seek to develop specific work capacities instead of general ones? How about we develop the ability of a basketball player to reproduce jumping and hopping performance throughout the course of a game. Also, how about we build a golfer’s capacity (through corrective exercise) to take all the swings he/she requires without getting hurt instead of running him/her through a modified strongman circuit to build “general fitness” or “work capacity?”

Eric Cressey has good work capacity by powerlifting standards; he can take a lot of singles over 90% of 1RM in a single training session and bounce back reasonably quickly.

Does that mean, though, that Eric can just walk outside and play soccer and be good at it because his “work capacity” is up? I don’t believe so, because work capacity is specific, not general. Instead, develop the specific capacity to play soccer! There’s no need to develop tons of different, and in many cases competing qualities just for the sake of saying we have a general capacity to tolerate a bunch of random events. All in all, it may be best to simply stick with the traditional methods of training and develop the specific capacities needed for a specific event or sport as opposed to taking hours during the training week for circuit training.

Just think of what higher-yield activities you could be doing instead while you taking hours of time out each week to do circuit training…

Sam Leahey CSCS, CPT can be reached at sam.leahey@gmail.com.

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9 Responses to “CP Internship Blog: Can Circuit Training Develop Work Capacity? – Part 2”

  1. Andrew Says:

    Just a comment to build on the mental toughness discussion from your last guest blog:I think that the focus you learn from lifting heavy weights with great technique has more carry over to sports than pushing through a circuit. Lifting heavy weights has taught me to focus on the positioning and movement of my body and how to execute. Anyone can fight through a circuit with enough loud music and teammates and coaches yelling at them. I did circuits 3 days a week for 3 months straight with my football team during the summer before my Senior year. They never got any easier, and wind sprints at the end of practices did not seem any easier either.

  2. Henry Says:

    Always on top of the game, good stuff, Sam.

  3. Jaden Says:

    Just a thought, relating back to mental toughness and circuits, wouldnt building mental discipline be more important than mental toughness. Per Vern Gambetta:

    Mental toughness is a cop out. I believe mental discipline trumps so called mental toughness all the time. All the champions I have been around had incredible mental discipline. Making someone puke in a workout or running someone until they drop does not build mental toughness. Find out who will do the workout when no one is there to make them do it. Find out who shows up and brings their “A” game every day no matter what the conditions and what the circumstances. Those are the people who have mental discipline; those are the people I want on my team.

  4. Mike T Nelson Says:

    Vern Gambetta is the man!

    It is pretty simple. The only thing we truly know is the SAID principle—your body get better at exactly what you do. I would add “how” you do it also (including the state you perform it in).

    Everything else is just varying degrees of transfer.

    Positive transfer: what you did made you a better player

    Negative transfer: what you did make you a worse player.

    How do you know? Test it and find out.

    While generalizations can be made, it will still come down to testing.

    I remember Cal Dietz saying once that if he wants to know if a new program will make an athlete faster, he tries it out on the track team first. Very easy to measure–they either got faster or slower.

    Rock on
    Mike T Nelson PhD(c)

  5. Sam Leahey Says:

    Jaden – i posted that exact blog post link from Vern into last week discussion thread already. Good stuff though and thanks for bringing it up again. I agree with him.

  6. Yael Grauer Says:

    Good stuff.

    Though it’s not about circuit training per se, all this reminds me of an excellent blog post by MMA fighter Rosi Sexton: http://rosisexton.wordpress.com/2008/12/05/what-doesnt-kill-you-makes-you-stronger-or-does-it/

    She writes about how you don’t build strength on top of dysfunctional movement patterns and makes the leap to assert that one shouldn’t stress a dysfunctional psychological pattern either.

    Although this can be done with sparring it is often done using circuit-type training with conditioning drills.

    Also in the article, Sexton brings up learned helplessness (as a potential byproduct of this type of training), and in the comments someone posted a bunch of studies about learned helplessness as it relates to sports; might be worth taking a look at.

    I agree that what makes you turn it on during a workout and during game day are two entirely different things, and that pushing through circuits doesn’t replicate it. But I’m not sure what would. It is hard to account for non-physical stressors in what is essentially a controlled environment.

  7. RT Says:

    I think there’s two things at work here, the psychological aspect and the physiological aspect. I think high level athletes need to be sharp with both, but with lower level athletes it could be one or the other. I doubt if a death circuit is going to be the difference maker in getting to the podium. Sure, it’ll be cool to see your buddy puke, but it ain’t gonna get him to run 4.32 for the 40.

    Your post is on the money but, as you pointed out, this is stuff that track coaches( at least the good ones! ) have been doing for decades, especially the general vs specific. Mike Boyle is just letting people know there’s some good stuff in the world of sprint training.

    Pertaining to power/speed events, there still is general and specific fitness. It’s just that it’s general fitness for a specific event. Specific fitness is literally the event(or portions of the event.) For example, tempo Runs, med ball circuits, mobility routines, bodybuilding strength training all come under the umbrella of general fitness for a 100 meter sprinter. Sprinting 100 meters, or sprinting anywhere from 0-100 meters at max speed( the % is dependent upon who you speak with ) is specific fitness. If I’m trying to get someone to run 100 meters in 10 seconds, EVERYTHING that I do, whether general or specific, must reflect that and your post has pointed that out very well.

  8. Sam Leahey Says:

    Thanks Kevin, it means alot hearing it from you man!

  9. George @ GMN Says:

    Solid post! I think people WAY exaggerate the benefits of circuit training. I also agree with doing the activity you want to get better at.

    If you want to be able to be a great tennis player and withstand the specific workload demands of tennis, you improve that by actually playing tennis…not by running stairs.

    You also hear a lot about athletes like pro-basketball players who are in shape, but not in “game shape”.

    Good stuff!

    -George D

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