In the programming series you mention targeting different domains:

- upper body capacity
- lower body complexity

How do you define the difference between capacity and complexity?

Matt! So sorry for the delay in answer here my friend - your question was "parked" but then slipped into bottom levels of the multi-story... 😅

It's a great question and definitely deserving of clarification. Terminology is important as we are constructing these theoretical categories ultimately for practical application.

- 'Upper-body CAPACITY': Yes, let's firstly consider the term 'capacity' in and of itself as it applies to this physical practice, because we can also have not only 'lower-body capacity' but also capacity of particular ATTRIBUTES (strength, mobility, balance... and even for "softer" attributes, although for these I use the term 'qualities', such as patience, determination, the non-physical side of endurance...).

In its broadest term, 'capacity' is effectively the "maximum which can be produced". In physical-training contexts, then, this is something which needs to be measurable & quantifiable in some way (reps, weight, time etc.). In 'Upper-body capacity', then, we are developing this maximal-output threshold. But, as we often use contexts of progressive intensity (e.g. increasing mechanical disadvantage in something like a 'Protracted pike pushup') it's not only the reps to consider, because 5x on a more challenging progression of such forms is of course not the same as 5x as an easier one. Here we start to see how, especially with things like bodyweight training where there are PROGRESIVE variations, that measuring 'capacity' in terms of numbers alone starts to fall short.

- 'Lower-body COMPLEXITY': when focus shifts to 'complexity', the idea of what "more" is, here, shifts. An iPhone 10 with 128GB storage has less capacity than an iPhone 10 with 256GB storage, but they are EQUALLY 'complex'. An iPhone 15 with only 64GB storage (nightmare!!) has less storage-capacity, but is MORE complex. Consider, however, that its complexity is also made possible by greater capacity in other areas, e.g. processing power. 'COMPLEXITY', then, can interact and is even dependent upon certain baseline capacities (e.g. a 'Handstand pushup' requires a certain level of strength-capacity, but it it also more complex than even a 'Tuck-planche pushup' because there also a balance factor involved which is a more complex attribute than raw-strength).

Broadly speaking, then, 'COMPLEXITY' is a spectrum of a greater or lesser number of interacting variables which ultimately contribute to a greater or lesser number of possible outcomes (more/less complex). When we use the term 'complexity' in training, then, we are concerned not necessarily with MORE of the SAME thing (i.e. increasing capacity, which is also a more 'LINEAR' road), but of greater LATERAL exploration of potential VARIABILITY and a greater number of possible outcomes. The simplest example here is a 'Pushup' - I go from 1 pushup to 10 = increase capacity/"linear" development. I go from 10 pushups to also learning a 'Negativa' and 'QDR' pushup - increasing complexity within the real of the 'pushup', and serving for more "'lateral" development.

Development of greater 'complexity' is what is significantly lacking in most traditional training systems in which we generally just feel that "more is better". 'Crossfit', as an example, has this at the heart of its entire ethos - how much can you do, how many can you do, how fast can you do. More ALWAYS = "better". It's the same for modern stretching practices/"yoga" - the "stretchier" you are, the "better" you are. We can also see this is a cultural-light - generally, modern Western cultures favour the quantifiable & measurable (modern Science simply cannot deal with anything which is not quantifiable, such as emotion). In Crossfit, a move toward complexity would be something as simple as exploring practices such as 'Locomotion' (which is why they often love it in classes). For modern postural-practice/"yoga", it would be as simple as getting off of the mat and moving around in the room.

IMPORTANT:
Why 'capacity' with upper-body & 'complexity' with lower-body? Whilst by now it should be clear that they are completely interchangeable (as a side-note, please always keep in mind that these categories of 'upper' & 'lower' are simply for purposes of structuring content & helping with focus in programming, as mentioned in the supporting essays), this is because the upper-body innately has more potential for movement-complexity (i.e. significant degrees of movement-freedom the spine, the shoulders, the arms/wrists & fingers...), so we orient toward increasing movement potential by increasing its CAPACITY (ie. strength, which enables the potential to manipulate the body in space).

The lower-body, with its deep hips has less complexity-potential (strength capacity in an able-bodied person is generally double lower than upper, albeit a crude calculation), and so we propose developing 'complexity' as the road toward increasing movement potential. Take someone with a double-BW back squat (capacity) and see if they can hold a 'Dragon' squat for 30" (complexity) - or even enter the position for that matter! Such a case, as I see it, represents a strong incongruence between capacity & complexity.

Ultimately, the individual will need to determine what THEY need to keep expanding their movement potential. The lower-body of a Yogi may be able to move in more 'complex' ways than a powerlifter, but they would likely increase their general MOVEMENT potential by increasing CAPACITY - and vice-versa. Take a look at where you are ehre & now & determine which is most appropriate for you at this time in any particular area - would you benefit better from a focus on capacity, or complexity? Everyone is different, and this will continually change over time.

Does that all make sense? Let me know if anything is unclear and feel free to continue the thread further.

All the best to you in your ongoing capacity & complexity-devleopment my friend!

Move well

J