Fitness

[Damer]

This has a direct impact on the choices you make in your workouts, the programs you choose and how you structure everything together. You'll need to think about this insight in terms of entropy and work done, changes achieved and energetic load changed. Then it'll make as much sense to you as it does to me, I hope.

 

[Laura Rainbow Dragon]

I understand the principals behind that quote, w.r.t. adaptive responses to training. But that is of course not the only thing that leads to improvements in efficiency.

Technique, for example, plays a huge role. Technique can improve with practice (provided one's practice isn't just reinforcing poor technique), but the improvement can be sped up significantly through the teaching of efficient technique.

When I worked at a fitness club I was also regularly participating in 5K and 10K road running races. Several of my colleagues participated in the same races. These were all aerobics instructors who could dance rings around me in a step class. (I taught only a yoga-styled class.) Yet not a one of them could come close to me in the road races. In terms of cardiovascular health, leg strength, and similar pure (not sure if that's the right word) measures of fitness we were all likely quite similar. Yet there were significant differences in our performance in our respective sports--even though stepping and running prioritize largely the same muscles and utilise quite similar musculoskeletal movement patterns. (Indeed, as a competitive runner I trained quite frequently on stairs--although admittedly I did not step down them backwards.)

Part of the performance difference is mental. I know what my body can do in a running race better than a step instructor does. I can pace myself better, push myself harder, etc. Whereas in the step class I'm spending a lot of mental energy on just on trying to learn the patterns. But I also have a more efficient stride in the road race due to better technique.

This has made me think of how we define "fitness" and how different aspects/definitions of fitness have different value priorities for different people. If I'm a competitive athlete, my sport-specific performance is very important to me. If the goal of my training is to facilitate ease of movement and minimize injury in my daily life, functional fitness is much more important to me. If I'm primarily concerned with remaining active to maintain heart and psychological health, maybe I just choose the exercises which are the easiest, mentally, for me to stick with.

@Damer are you aware of any studies that looked at the benefits of variety in training versus constantly repeating the same training modalities? As a runner, I know we considered cross-training to be primarily a means of maintaining fitness while minimizing injury risk (or while unable to run due to an injury that had already occurred). Cycling and swimming, for instance, build cardiovascular and muscular strength needed for running without the same stresses running puts on the joints. I am wondering, however, what the science says about adaptive response to exercises I'm already good at versus ones which are new to me. (Assuming both exercises recruit similar muscles.)

If I practised step aerobics every day, my performance at step aerobics would improve to a greater extent than my running performance would improve if I put the same time and effort into running training, because, being a beginner at step aerobics, my scope for improvement in technique is so much greater there than with running. But in terms of cardiovascular health, muscular strength, and functional fitness, which reaps greater rewards? The activity I'm already good at, in which pretty much 100% of improvement is the result of adaptation to increased load? Or the activity in which my brain is also getting a workout, trying to figure out what, exactly, to do? I imagine such an experiment would be difficult to conduct, given discrepancies in how one perceives effort expended in familiar activities versus unfamiliar ones.

Some interesting food for thought. Thank you.

 

[Damer]

@Laura Rainbow Dragon thank you for adding a very thoughtful response and some very logical ideas to my, admittedly, condensed quote. I am going to build on what you've given me, add some studies and also explain it further. But, for clarity's sake, let me backtrack a little and explain fitness.

As you've already said, fitness is the body's adaptation to an external stressor. Evolutionary biology tells us that these adaptations take place so the body can survive in an environment that adds an energetic load to it. So the moment the adaptation occurs, the energetic load of performing whatever it is we need to perform, drops and, depending on the degree of adaptation it drops quiet significantly. For this to happen the body needs to allocate resources, so the stimulus needs to be persistent and consistent.

The adaptations that happen, however, are only partially physical. The body needs muscles (and tendons and ligaments) to move and under an external stressor that tires it out these will get stronger so it can move more easily. At the same time the muscles are controlled by the brain. So adaptations, to a varying degree, are always on three levels: Physical, neurochemical (psychological based on neurotrasmitter production according to an internal perception of the value of each activity we engage in), neurobiological (physical as the central nervous system creates the connections it needs to, to better control the body). What you call technique is exactly this kind of coordination between mind, body and brain to produce a vastly efficient movement that can deliver a powerful output for as little energy expenditure as possible.

Your experience of a step class bears this out. Physically your limb strength was as good as that of your colleagues, but you needed to learn the steps which means your brain needed to create different wiring to control your body and you had to have confidence it its ability to produce a smooth, flowing movement. A thinking brain uses the same fuel as working muscles: adenosine triphosphate (ATP) so the same movement was more tiring for you than for them, from an energetic point of view because you had not achieved the same efficiency of motion. Similarly, when the odds were reversed, in running, your technique: mind, brain, body coordination was perfect. Each step took a lot less energy for you than it did for them, hence you now outpaced them with ease.

This also brings us to your final paragraph about doing something every day. The moment you become efficient at it, it no longer challenges you. You then need to mix things up again to achieve the same results in mental, physical and psychological fitness or risk backsliding (there is an additional complexity here which I will not address this time). As in your example, you cannot get better at your chosen sport just by doing it on its own. You need additional and varying exercises and challenges (which is counterintuitive) precisely because of the body's tendency to adapt, habituate and then achieve a lowering of the energetic load associated with that activity.

A 2022 study that looked at gait and stride (they call it "sinusoidal speed") and concluded that across age groups, as we age, the body's adaptations to an activity that is universal and fairly constant in our life enable us to maintain gait and stride on a fairly constant degree of adaptability as we age, provided there are no underlying physiological impediments. This is important because it shows that the body's adaptation capability is always there, no matter the age and, provided we "use it" we tend not "to lose it" even as we age. (There are some caveats on this, obviously, but the study focused on walking which is accessible to all ages).

A 2017 study on rats (they're nearer to us in some aspects than we think) showed that habituation in running on a wheel improved locomotor performance. Locomotor performance (i.e. the ability of, rats in this case, to perform a physical activity to a repeated high standard) is what we call efficiency gains through good technique. They improve performance, tire us less (because the energetic load drops) and require a complex interaction between mind (motivation), brain (nervous system coordination) and body (the activation of the body's kinetic chains in a specific order).

From all this we can gather that habituating to exercise is important for achieving a level of fitness that is good in terms of how the body uses glycogen stores, delivers oxygen and ATP where needed and recovers after exertion.

Here's where it gets interesting: none of us exercise enough. We need, really, three-four hours a day (maybe more if the intensity is low) to maintain this level of psychological, mental and physical fitness. So this now leaves us with the question of how to best deal with it? Given that the body and mind are in a constant state of flux but constantly seek homeostasis (a balanced, stable energetic state) the best way to do that is by mixing exercises/activities. This constantly introduces adaptations that, over time, are disproportionate to what we need (for example none of us need HIIT training to feel happy and healthy in our daily life) but HIIT training triggers adaptations that raise our body's (and mind's) capacity disproportionately. This, in turn, means that when our body and mind lose some of that high level of performance because we do not exercise them enough, the drop is not as precipitous or catastrophic for us as we have pushed them to adapt for a higher level of performance. A 2020 study that looked at the effects of HIIT on people with type-1 diabetes which is incurable, showed increased levels of awareness, management and sensitivity after HIIT which was designed to be different all the time.

Within DAREBEE we've long taken the stance that each workout needs to be different and working out long-term needs to be challenging, based on our understanding of much earlier studies. It's an approach that is now being proved correct with more modern, granular studies that show that "mix and match" is a valid, long-term health improvement strategy.

A 2012 study showed that variability in training kept the psychological element going stopping demotivation from developing and had, as a result, better overall fitness effects than doing the same thing all the time. Its results mirrored a 2009 study on the subject that used children to measure eating patterns and motivation and again, a 2019 study that looked at motivation patterns in already fit males, lifting weights.

Summing up the quote I shared: We want to achieve efficiency when we train, but once we do, we need to mix it up and seek a fresh challenge. (Ideally). Thank you for lighting the spark with your reply and examples.

 

[Laura Rainbow Dragon]

Thanks Damer!

I had not considered the ATP requirements of thinking. Hence: the novel exercise isn't just perceived as more taxing. It physiologically is more taxing.

Interesting then, that the studies on variability in exercise demonstrate that the direct benefit of variability is an increase in motivation to train. Any physiological benefits that accrue are secondary as a result of the subjects choosing to train more (at least in those studies you referenced).

I would think there are also benefits to brain health (cognitive function) in gaining proficiency in a variety of different training modalities (as opposed to simply mixing up the order of the same familiar exercises) in that learning in general benefits brain health. (As does the physical exercise itself. So double win there!) These studies showed promising results re: the benefits of learning new skills on cognitive health in older adults which persisted for a full year after the intervention. (Something I definitely think about at my age, and after watching my own parents' cognitive decline--quite precipitously during the final two years of his life in my father's case.)

Time for me to finally commit to doing Fighter's Codex, perhaps. And also some more HIIT. (Even though I really don't like the latter and would much rather just go for a run!)