[Giselle]: I mean, that's true. So there's a speed component, right? Where, so as you get faster, you are thinking about accuracy a lot more and you are starting to... You're right. Absolutely.

[Rhonda]: And kind of more...

[Giselle]: And I think the point that you're bringing up, which I think is so important is it's a spectrum, isn't it? So it's not really often just one or the other, right? There's some that have certain types of activities that are going to have a higher aerobic content, maybe even skill. But, you know, as I've often been reminded by many of my physical therapist colleagues, it's like, it's actually also kind of impossible not to have some level of skill in anything you do. I mean, it's hard to be completely mindless on whatever you're doing, even... I mean, obviously, with weight lifting, even weightlifting is requiring some cognitive loading.

[Rhonda]: Yeah. You don't want to get hurt.

[Giselle]: Right. Exactly. I'm not just like throwing weights around. So, yeah. So the idea is that there's always some element of skill, even in biking, even in a stationary bike, because you're thinking about your speed. It's kind of the issue of the degree and also, again, the issue of intensity and that the two are probably, you know, obviously have different types of mechanisms that may be contributing to repair, but the idea is they may be different. And particularly when we're thinking about cognitive circuitry, as an example, we may want to be thinking about how we could add more cognitive loading, right? And what's curious about this sort of idea of cognitive loading, you know, many times when I talk to people about cognitive loading, the first thing they want to do is tell me about, you know, like a crossword puzzle they've done and I'm going, "Well, wait a minute."

You know, our brain has evolved to be pretty effective in movement through space. I mean, it's pretty, you know, pretty on board when it tries to figure out how to get from point A to point B. I mean, it's been important in our evolution. It's probably why we're still living today because we've been able to avoid animals that harm us, we've been able to be successfully going for meals. I mean, the idea of movement in space is huge for us. And the point there is that that's cognitive loading. Myself, just problem-solving movement through space, whether that be because of the skill that I'm engaging or even through a different environment, right? So the idea of mixing that up, changing the environment is going to be another type of cognitive load.

[Rhonda]: There's been animal studies that have shown that doing that exact thing, like changing the environment and particularly putting an animal in a more enriched environment, it increases synaptic connection and long-term potentiation, you know, all these things.

[Giselle]: Right. Absolutely. And what's interesting about that field though is even in the context of environmental enrichment, many times, it's also what else is in there like the wheel, or... I mean, there's always a physical component that they find is also important. So I think it kind of, just, as I said, kind of goes back to the idea that movement through space is a big deal for our brain it itself is a cognitive load. We can definitely ramp that up in a lot of different ways. Certainly from a skill point of view, we can. From an environmental enrichment, making it a novel environment for us. Moving effectively through space is also...in a new space, in a novel environment is also pretty big. I know there's a lot of interest now looking at natural spaces and what that does for cognition as well. And there's some really interesting things coming out of that. Again, kind of tying it back into movement though, is really where it gets really interesting. Yeah.

[Rhonda]: Right. I mean, certainly... So in addition to, you know, all the benefits that exercise...ad I mean, there's been studies showing that, you know, in Parkinson's disease patients, Parkinson's disease patients that do, you know, a certain amount of, you know, 30 minutes of exercise, you know, moderate to high intensity increased BDNF and their plasma and BDNF crosses the blood-brain barrier. It's a growth factor, it's important for maintaining synaptic connections, for growing new neurons. And, you know, it's certainly important for repair of, you know, damaged brains. So, you know, there's definitely lots of factors that probably, as you were mentioning, there's the, you know, the combination of these things, exercise is anti-inflammatory, you're making anti-inflammatory cytokines, and, you know, those things also are doing stuff in the brain. As you mentioned, the brain and body are very connected. They're not disconnected like we thought. In fact, the immune system, you know, these immune factors are getting into the brain. Our lymphatic system is connected, you know? So there's definitely a connection there.

[Giselle]: Absolutely. I think the one thing and tying back kind of what, again, what you were saying, so this whole idea of how connected, obviously, as you said, we're learning a lot about that. But also, again, the idea that, which I always like to emphasize, that the brain is not a passive recipient of this. Meaning there's a lot of signaling, we're probably just beginning to understand in terms of what the brain needs and the idea that as you kind of create these sort of metabolic demands on these circuits by virtue of how you're using your brain, right? By virtue of the taxing nature of skill and the taxing nature of a cognitive load in the context of movement, that those neurons and those synaptic activity and that high metabolic demand is signaling the need for more fuel, you know. And so, the idea there is all those sorts of pathways that are, you know, metabolic in nature and driving changes in blood flow that are also kind of interesting because like I said, many times we do tend to think about these sort of lifestyle effects as sort of being the sort of global kind of glow, your body glow. I mean, it's sort of like it's a sort of wave over your whole body that suddenly gets better. It's like, "Well, no. No." I mean, these it's very active and it may be even more specific than we think.

And I think as I said, the brain is a great model to begin to understand that because it has some kind of cool repair mechanisms. The question is, how does that signaling start? How much of that is brain driven, right? And top-down. So we're not even talking about, you know, from the periphery in, I'm talking from the brain out. Brain is signaling to the periphery, what do I need now to be able to accomplish what I need to accomplish, reaching my new level of homeostasis? I am asking for a new level of a type of connection that I now need. I'm going to signal for the type of whatever support I need to make that happen. Right?