Dr. Samuel Buckner (3:20)
Yeah, that's a great question, because I think a lot of what I'm interested in is how we can make muscles grow, but also what that time course looks like and, you know, how much growth we can hope to achieve over time. So these are all questions that, you know, I, I'm trying to answer. And you know, we chip away at it a little bit at a time and, you know, you never answer everything you want to with a single study. But I suppose when I was new to research, you know, I had read textbooks and I had taken coursework and I was learning about hypertrophy. And you know, even today in class I was teaching on hypertrophy and we, I put up the figure from our textbook. And you know, for muscle growth, it's traditionally suggested that you need to lift around 8 to 12 reps to or near failure in order to make your muscles grow. So a weight that's relatively heavy. And, you know, that's what I had learned and that's what I had mostly done in the gym up until my graduate work. And then the early years of my graduate work were actually focused on low load alternatives to making muscles grow. So this idea that you don't need to lift heavy weight, you don't need to lift the weight that you can only lift 8 to 12 times in order to make your muscles grow, and you can accomplish the same overall adaptation as far as growth is concerned. So, you know, early on in my graduate work, I began to realize that it was about fatiguing and activating a muscle. And something about that process stimulates a signaling cascade that, you know, makes that muscle grow. And it's interesting to me that, you know, we have so many alternatives now that we can recommend to people who maybe their preference isn't lifting heavy. Maybe they would prefer to lift a lighter weight, or maybe they're contraindicated to lifting heavy weight. So a lighter weight alternative is an attractive option. Another thing I discovered along the way that I suppose I didn't necessarily expect is somewhat of a divergence between a strength adaptation, a muscle growth adaptation, and a strength adaptation. So when I began studying low load alternatives for skeletal muscle growth, what we found is you would grow, but you wouldn't get strong like you would if you lifted heavy, so the growth was there, but the strength adaptations weren't always there in the same way. So that really challenged my thinking, or at least as far as the conventional story of adaptation, because a textbook, again, a textbook will tell you that when you begin training, you, you increase strength by neural mechanisms in the first several weeks. But somewhere around weeks 3, 4, 5 or 6, neural adaptations are becoming less and you begin to become stronger by hypertrophic adaptations. Right? So it's believed that muscle growth becomes the primary reason you become stronger as you progress in a training career. But we were finding that people could grow even if they're trained, and that growth wouldn't always necessarily lead to strength and vice versa. We found that very trained people, people who had been lifting for a long time, could get stronger and that strength was not always accompanied with a muscle growth adaptation. So those are things that I think probably fuel a lot of my current curiosity. You know, how can we get bigger or stronger? And what's the relationship between these adaptations? But not only that, what does muscle growth look like? In the context of most research we do at a university is eight weeks, 12 weeks in duration. In the United States, they're mostly eight weeks. And a lot of people don't know this, but studies are eight weeks because of our semester schedule at school. So in the fall you have to finish before Thanksgiving and in the spring you pretty much have to finish before spring break. So that gives you about eight or six weeks to do a training study. So a lot of the knowledge that we have on skeletal muscle adaptation is just a very small snapshot of what adaptation looks like. And because of that, since I've got my job here at usf, I've tried to do longer studies than what's typically been done. And we recently wrapped up data collection on a one year study. So looking at growth over an entire year, and I think we have some pretty fascinating results. It's not published yet, it's not even written up yet. But we've taken a glimpse at the data and I think the future for me is just finding unique and different ways to answer questions and design studies in a way that's going to add to what we currently know. But a one year study, just for example, I think we need more studies like this. But to recruit about 33 to 35 people, it took me six years. It's a study I ran in the background. Because a one year study is not going to get me tenured at a university when it takes six years to get your sample Size, but it's something that every year we recruited for and you know, we'd maybe recruit 10 people and a year later half of them dropped out. So we're like, okay, we have to run the study for another year and things change. Yeah, it lets us. Some pretty cool insight.