The Power-Capacity Continuum

Several days ago I posted the following quote from a Charlie Francis lecture I was watching onto my Facebook page and finished it with a few comments of my own:

“A pitcher should have a pretty good aerobic component. They need to recover and they need to be able to heat their joints which the aerobic capacity allows them to do. The power component is big but the aerobic component is big too.” -Charlie Francis

My comments: Now the real fun is in figuring out the ways of developing that capacity without killing the beast and turning them into an endurance athlete (as they used to do to pitchers back in the day). For some reason everyone hears “aerobic” and they get scared but I think much of this fear comes from a lack of understanding how to train the system in order to develop sport specific work capacity.

What followed was an enormously long discussion (something like 180 total posts) about Charlie’s quote and a lot of people misunderstanding what Charlie Francis was saying. That misunderstanding probably stems from Charlie using the term “aerobic” which tends to make people feel uncomfortable and think that if something is “aerobic” then it is is some way not “athletic” or not necessary for any other sport besides endurance sports. The interesting thing is that if we removed the word “aerobic” and changed it to the phrase “work capacity” (or just “capacity” as I did in my comments that followed) most people probably wouldn’t have a big problem. The issue is more one of semantics then anything else because if you heard Charlie Francis discuss the training approach there is probably little that anyone would disagree with.

The Power-Capacity Continuum

All sports lie on a continuum between Power and Capacity. Power is the ability to do something for a shorter period of time but do it at a maximal or near maximal effort and then enjoy a complete or nearly complete recovery period. Capacity is the ability to either do something for a long period of time, such as run a marathon, or be able to express high, powerful efforts repeatedly with minimal or incomplete rest. Not only can all sports be classified on this continuum but energy systems can be classified in this manner as well:

Aerobic Power
Aerobic Capacity

Anaerobic-Lactic Power
Anaerobic-Lactic Capacity

Alactic Power
Alactic Capacity

The Power-Capacity Continuum looks something like this:

Olympic Lifting Marathon
Power Lifting Ironman Triathlon
Track and Field Throws


As you can see, on both ends of the spectrum are the extremes. To the left you have events that require huge amounts of output but are followed by long periods of rest and on the right you have events that require you to perform efforts for an incredibly long period of time with no rest at all.

As I stated earlier, all sports fall somewhere on this continuum between the two sides and most team sports are closer towards the capacity side as they require the expression of high energy outputs followed by minimal or incomplete rest and they require this to be done over the course of an entire game or match.

Using the Continuum to Evaluate Sport

To successfully use the continuum you need to first understand where the sport in question lies keeping in mind that various positions within the sport may be shifted towards one direction or the other.

For example, teams sports are generally “capacity” driven. While the athlete needs to output high amounts of power and strength to often be successful they need to do so over the course of a game with minimal or incomplete rest periods as well as be able to recover adequately and perform in a similar manner over the course of a long season. Thus, these sports are often categorized as being “alactic-aerobic” or requiring a large work capacity to support the athlete’s ability to consistently repeat their effort at the highest level. Now, when we start to look at positions within the various sports we see can see even more distinctions. Here are some examples that come to mind:

  • Football is a sport skewed toward capacity and alactic-aerobic in nature (even more so now a days with teams running hurry up and no huddle offenses). However, the guy on my team that does nothing other than run back kick offs does not need as much capacity as my running back who gets 40 carries a game because the guy running back the kick offs pretty much goes in, does his thing, and then gets a really long rest period before he needs to do it again. While many of the guys on the field are skewed towards the capacity side the kick off returner is skewed more towards the power side.
  • Baseball is an interesting sport as there can be a huge amount of downtime for most of the guys on the field (especially the designated hitter – who would be skewed most towards the power end of the continuum). The players in the field are not as capacity driven as the pitcher, who needs to make 100 or more pitches at extremely high velocities over 5-6 innings with brief rest intervals (longer rest period when his team is batting obviously). The pitcher needs a pretty sound alactic capacity to keep repeating those efforts.
  • In soccer you would see a similar difference between various positions on the field with regard to the amount of running guys do and the speeds at which they do it. Additionally, the goalie would lie more towards the left of the continuum than the others players on the field.

Training for Sport

Once you analyze where the sport is on the continuum you must then determine ways of going about testing the athlete to see what sort of qualities they currently posses and what sort of qualities they are currently lacking. This will allow you to plan training and determine which qualities to train first. Unfortunately, one size does not fit all. As we see above, while all sports have similar general qualities (which I discussed in my article Developing Requisite Competencies) after a certain period of time it is essential to then begin to focus on the specifics of the sport and raising the sport specific qualities necessary for success. As I discussed above, this may mean that some players on the team, depending on position, may have different targeted training goals. Just because they play the same sport may not mean that they should have the same training program.

As you develop the training program keep in mind where on the continuum the sport falls and ensure you are preparing the athlete for those sports demands. This may include thinking outside of the weightroom (remember, strength isn’t the only factor in developing sports fitness). When thinking about capacity sports be sure to choose methods that work towards the similar demands of that sport. Initially, you may start very general as training specifically for the sport may require the athlete to first develop overall fitness, mobility, or foundational strength in order to progress further. Dr. Drabik, in Children & Sports Training: How Your Future Champions Should Exercise to be Healthy, Fit, and Happy, makes the following distinctions (pg. 94):

“General endurance is the ability to perform over a long time any physical effort involving numerous groups of muscles that has a positive influence of sports specialization.

Directed endurance is the ability, based on aerobic fitness, that creates the functional basis for special endurance. In training methods the structure of movement is identical and the character of an athlete’s effort is similar to that of the sports specialization.

Special endurance is the ability to perform efforts typical in a given sports discipline, for the same duration as that required in the discipline, while preserving the necessary quality of techniques.”

The methods you choose to employ within each of those three “buckets” is up to you but the phase of training should have a theme and a goal of achieving some sort of physiological outcome.

Sequencing the Training Week

The Charlie Francis quote that started this article created quiet a stir because Charlie used the word “aerobic”. What it really comes down to is that the aerobic system is critical as it underlies all other energy systems and the more developed the aerobic system is the better the other energy systems can function. This does not mean that a baseball pitchers needs the aerobic capacity of an Ironman Triathlete but it does mean that they need to develop a work capacity (noticed I didn’t say “aerobic capacity” because that phrase tends to upset people) to support the demands of the sport.

In training, it is impossible to go hard every single day – I shouldn’t say it is “impossible”. It is entirely possible but it is also entirely reckless and potentially damaging to the individual. Thus, the week needs to be sequenced properly. Charlie Francis was fond of the “high-low” approach where he group high intensity training stresses on one day and low intensity training stresses on other days as a way of allowing the athlete  at least 48hrs to recover from the intense training. Generally, the “high” days were more powerful, short, alactic efforts and the “low” days were more extensive in nature – even for the fastest 100m sprinters in the world at the time (a sport that would be shifted much more to the left of the continuum) Charlie understood the importance of general fitness and developed their aerobic systems to a certain level using things like tempo runs and various circuit training methods to build them up to a certain point and then maintain that while they focused more on sprinting and preparing for competition. They did very little work in the “middle zone”, which Charlie referred to as being “Too slow to be speed work and to fast to be recovery work”. This work tends to be more lactate producing and isn’t really representative of the energy system demands for American Team Sports (as I wrote about in a previous article, Some Thoughts on Training the Lactate System).

As a way of honoring this “high-low” approach one should sit down and determine the training methods at their disposal that represent high and low training stressors, determine what aspects these training methods target (which energy systems and are they more power or capacity driven), and finally sit down and structure the training week in a way that makes sense and has a good balance between intensive and extensive training and allows the athlete efficient time to recover and adapt so that they can make adequate improvements.

Wrapping Up

What we can learn from all of this:

  1. All energy systems can be broken down into “power” or “capacity”
  2. All sports lie on a continuum between power and capacity
  3. Different positions within the same sport may lie in different places on the power-capacity continuum
  4. Developing work capacity in general before transitioning to sport specific work capacity is important
  5. The aerobic system drives all other energy systems and is a key target when developing general work capacity
  6. Choosing training methods appropriately is essential when setting up the training week
  7. Training methods can generally be classified as either “high” or “low” stressors
  8. Sequencing training through out the week is the key to ensuring that the athletes not only get the most out of the high intensity days but are also able to recover and optimally adapt to those training days