Strength Training, Sports Injuries, and Healthy Aging

Brent: Welcome to the Life Lab by Death Clock. I'm your host, Brent Franson. The mission of Death Clock is to help 100 million people live ten years longer. Today, we speak with Doctor Brian Feeley about exercising as we age and avoiding injury. Doctor Feeley is the chief of sports medicine and shoulder surgery at the University of California, San Francisco.

Brent: He's an active team physician for the San Francisco Giants. He is also the director of a lab at UCSF. It's a wide-ranging conversation where we touch on almost any sport you could participate in, how he thinks about it, common injuries that he sees as an orthopedic surgeon, and how to think about maintaining muscle and fitness in middle age and beyond.

Brent: He's a wonderful guest. Hope you enjoy.

Brent: Doctor Brian Feeley, welcome to the show.

Brian: Thanks for having me.

Brent: I'll let you share your own background, but today we're going to talk about strength training and preventing injury, which is very near and dear to my heart. I'm 44, and I've been trying to crank up my strength training regimen, and I keep injuring myself in minor ways that don't require seeing a surgeon like you, but that take me off track for several weeks.

Brent: I'm looking forward to this. Before we do that, please give us a sense of your background and potted bio.

Brian: Sure. I am a shoulder and knee surgeon at the University of California, San Francisco, which is a unique University of California campus because we don't have an undergraduate campus; we are strictly a health sciences campus. We have a nursing school, medical school, and all the departments, bells, and whistles of a health services group.

Brian: Sometimes people ask what sports teams we cover within the university. We don't really have that, so it's a unique place. I specialize in sports medicine and shoulder surgery, including shoulder replacements, rotator cuff repairs, ACL injuries, and meniscus surgery—handling all sorts of athletic injuries and managing different sports teams, including professional and high school teams.

Brian: We see the full gamut of injuries. One of my other jobs is running a basic science lab where we look at muscle injury and recovery. We study how progenitor cells within muscle can be activated in a good way to promote recovery, or how they fail to activate, leading to muscle degeneration, sarcopenia, and impaired recovery as we get older.

Brent: As a surgeon, what is the split between working on professional athletes whose day job is being an athlete versus everyday people who get injured?

Brian: It's about 10,000 to 1. The reality is that we hear when professional athletes get injured because it makes the news, but they rarely get injured. They're in exceptional shape—partly due to genetic components—and overall get injured relatively infrequently.

Brian: When they do get injured, they have a whole team of people evaluated before seeing a surgeon. The likelihood of a professional athlete needing surgical intervention is really uncommon compared to the hundreds of thousands of people skiing in Tahoe, weekend warriors playing in adult leagues (which keep us busy but can be disastrous for ACLs), and our growing aging population. Older adults, previously told in the '70s and '80s to sit in an easy chair, are now out being more active than ever before.

Brian: The majority of our patients are people who want to remain active, people who have picked up new sports, and people trying to stay healthy as they age.

Brent: As a surgeon, how has your perspective changed? What do you see repeatedly where you'd tell people at a dinner party, "Don't do this thing"? We see people every day undergoing surgery who could have avoided injury, or who are approaching a sport the wrong way.

Brent: What is the main thing orthopedic surgeons sit around discussing, wishing people wouldn't do to cause these injuries?

Brian: I'll answer that in two ways. First, poor form leads to a higher injury risk. We still see a fair number of CrossFit injuries. CrossFit has evolved; it used to be less common, but now it's much more mainstream, with greater diversity in workouts. It isn't everyone working out for three hours to the point of extreme muscle breakdown.

Brian: There are still movements that put your body at risk in CrossFit, especially really deep squats and ballistic overhead movements. We still see shoulder dislocations and meniscus tears from loaded twisting movements. Conversely, the most common concern I hear is patients saying their doctor told them to stop running due to knee pain or early arthritis. But there is little evidence that regular running leads to progressive cartilage degeneration and arthritis.

Brian: Unless you are training for extreme ultramarathons with pain and swelling, running won't inherently ruin your knees.

Brian: If you love running and miss it as you get older, there's no real evidence you need to stop. On the other hand, if I had to pick one sport to drop, I would tell people to drop skiing. It's expensive and fickle; you're dependent on conditions and other people, and you attach a 180cm lever to your knee that puts your ACL at risk. Especially for high school athletes in-season, unless skiing is your main focus, be cautious.

Brian: You're dependent on conditions and other people to not get injured. And you are attaching 180cm fulcrum to your knee and saying, please, please, please don't tear your ACL. So especially for in season high school athletes that don't want to ruin their next season. As if skiing isn't your thing, you have a lifetime ahead of you of doing that.

Brent: Be cautious with CrossFit and skiing, and be wary of advice to stop running if your knees hurt. We heard this from Michael Fredericson in a previous episode—outside of extreme cases, running doesn't make your knees deteriorate faster than they otherwise would.

Brent: There is even evidence suggesting it can strengthen them and make them healthier.

Brian: Yes. Dr. Feeley's group at UCSF conducted a study performing MRIs on marathon runners before, immediately after, and one month following a marathon. They found knee cartilage appeared slightly swollen right after running 26 miles, which is a normal response to load.

Brian: A month later, the cartilage returned to normal. Multiple studies show cartilage swells with activity as a healthy biological response to load, then normalizes over time.

Brian: There is a risk-benefit profile to consider. The overall health benefits of exercise far outweigh the low risk of running or exercising, especially when looking at the whole body.

Brian: We tend to isolate specific body parts and think knee pain means running is bad, but keeping your heart, brain, lungs, and liver healthy will help you live longer and happier.

Brent: Is there an exception if you've had a previous injury? I had an ACL repair from skiing in my mid-20s, and that knee causes me issues. Should people with prior injuries be more cautious with running?

Brian: I politely disagree, depending on genetics and meniscus health. For the general population, if you aren't experiencing persistent knee swelling or pain that stops you from running the next day, it is likely safe.

Brian: The biggest drivers of arthritis are genetics and abnormal joint loading. Regular running isn't inherently bad. Running ultramarathons with missing meniscus cartilage or a loose ACL isn't ideal, but running 5k to 10k races or 10 to 12 miles a week is usually fine.

Brian: Absolutely. No problem.

Brent: How do you view board sports that aren't skiing? Since surfboards aren't attached to your feet, I assume it's different. Do you categorize surfing, snowboarding, or skateboarding differently?

Brent: Do you think about them differently?

Brian: Each sport is different. Surfing is generally safe; the most common issue is arm fatigue from paddling. Shoulder dislocations are rare, and ACL tears are extremely uncommon in surfing unless doing high-risk maneuvers on massive waves.

Brian: Snowboarding injuries mostly involve upper extremities like wrist fractures, shoulder dislocations, or concussions. Knee injuries are less frequent compared to skiing. Skateboarding spans a wide spectrum of risks due to uneven urban terrain and high-impact tricks at skate parks, leading to ankle and knee injuries.

Brian: And then skateboarding runs the entire gamut because you have kind of the best and worst of both worlds. You are on uneven surfaces with small wheels, often in urban areas, plus the ability to go into skate parks and do tricks. So you have all the ankle fractures, knee injuries. The skateboard behind me is from Chico, Brennus, who's a well-known skateboarder who injured his knee basically landing a trick that I would say should only ever be seen on videos.

Brian: Overall, the overall risk profile for these board sports remains relatively low if approached progressively as skill increases.

Brent: So skiing stands in a category of its own as more dangerous than those other sports?

Brian: Proportionately for the number of participants, we see more ski injuries in our sports medicine clinic than almost anything else.

Brent: How do you view cycling? I live in Boulder, Colorado, where cycling is huge. Crashing while cycling in my 40s or beyond scares me, even though I love the exercise. How do you evaluate cycling?

Brent: I don't know, maybe you are an orthopedic surgeon. You're going straight in the emergency room. But crashing, cycling in my 40s or beyond that scares me. Even though I like the thought of the exercise. It's beautiful. So how do you think about cycling?

Brian: We see plenty of mountain biking and road cycling injuries in the Bay Area. The most common acute injuries are clavicle fractures and AC joint separations. Road cyclists often suffer worse impacts than mountain bikers who tumble into brush.

Brian: So the most common things we see are clavicle fractures and AC separations. And they're not super common, but they're not all that uncommon. They're actually a little bit more common in road bikers than mountain bikers, because mountain bikers, when they fall, tend to skid and land oftentimes in bushes, and will get a lot of road rash or tree rash, I guess.

Brian: However, the non-impact joint stress of cycling is low. It is non-weight-bearing and lower impact than running or hiking. When I bike to work, I descend slowly to avoid ending up in the ER, and push hard on the uphills instead.

Brian: But you still have the relative risk of falling. So when I ride my bike when I try to ride my bike a fair amount to work, I ride really, really slow on the downhill because I don't want to see my colleagues in the emergency room, and I tend to push the uphill because I just hopefully won't fall going uphill.

Brent: The basic physics of how fast you're going probably apply to both your mountain biking points and what you're just saying about road biking going up and down. I mean, I think mountain biking. I grew up dirt biking and it became very obvious to me, you know, you're not you're unlikely to die dirt biking. You might break a bone or something, but you're going around tight corners, you're in the woods.

Brent: You're not in an environment that's full of cement and metal. And then if you're on a road motorcycle, all right. Everything around you is really hard and you're going much faster.

Brian: The biggest difference on the road is vehicle traffic. A car hitting a cyclist introduces significant kinetic energy that is completely outside the rider's control.

Brian: It's entirely not in your control. And then you have the kinetic energy of the car hitting you as well. So mass times velocity squared. Even a car going ten miles an hour can cause a lot of damage.

Brent: Okay, but as an orthopedic surgeon, a sports medicine expert, you don't ski, but you will get on your bike.

Brian: I will try almost any activity. I used to ski and snowboard, but raising five kids makes ski trips expensive and logistically challenging, so life got busy. Skiing is just lower on my list compared to accessible activities.

Brian: I prefer sports with a one-time equipment cost over recurring fees—like basketball, surfing, or biking—where you pay upfront and can participate freely afterward.

Brian: You can go out and play surfing high up front. Cost. You need a board and up here a wetsuit. But once you have it you're good. Once you buy a bike, you can bike whenever you want.

Brent: How do you approach sports for youth? Would you discourage sports like football or gymnastics?

Brian: We have four daughters and a son. My youngest daughter plays flag football, which is very safe. My son hasn't shown interest in tackle football, and we would likely discourage it, though football does offer team-building benefits.

Brian: One issue in youth sports is early single-sport specialization. A great aspect of football is its defined fall season, allowing kids to participate in track or baseball during other seasons.

Brian: Tackle football carries higher long-term risks, especially if played continuously over many years.

Brent: Is that risk specifically regarding head injuries, or orthopedic injuries to knees and joints as well?

Brian: For boys, football carries a similar overall orthopedic injury risk to soccer, basketball, or lacrosse. Knee and ankle injury rates are comparable across those sports, heavily driven by overall athletic exposure.

Brian: Long-term accumulation of injuries in football mainly affects players who continue through high school, college, and professional levels, facing risks of chronic shoulder, neck, back, or head issues.

Brian: It's a dynamic decision for each athlete. If someone has had multiple ACL tears and prolonged missed seasons, we might discuss transitioning to lower-impact endurance sports without cutting and pivoting.

Brian: That nuanced approach—aligning an athlete's goals with their physical capabilities—is what drew me to sports medicine.

Brent: That's an interesting point about playing time. A football roster has 50 kids compared to 11 in basketball, so average game exposure per player is lower.

Brent: We often envision NFL Hall of Famers taking hits every game, which doesn't reflect the typical youth football experience.

Brian: Exactly. Playing a few years as a backup, gaining teamwork and leadership skills, and trying other sports isn't harmful.

Brian: However, if a young athlete has had an ACL tear and multiple concussions, exploring other sports makes sense. Over-specialization in sports like basketball often leads to high cumulative tendon stress early in life.

Brian: In basketball, Achilles ruptures used to occur mostly in players in their mid-30s. Now we see elite players experiencing them in their mid-20s due to year-round tournament play with multiple games per weekend.

Brian: What is the difference. Well they've been playing just basketball since they were ten 1112. And when they go to an AA tournament they're not playing one game. They're playing three maybe six games in a weekend. The overall cumulative load on that tendon is a lot more at a much younger age. And we don't know what's going to happen to these guys.

Brian: Like Tatum looked great for my oldest daughter is a huge Pacers fan. Hopefully Tyrese looks good next year, but we don't know for sure. And we don't know if this means that their careers are going to tail off. And we don't know if that's really because they were playing so much basketball so early on.

Brent: And they're recovering really quickly. Are the surgeries getting better? Is the technology getting better?

Brian: Are they recovering quickly?

Brent: I mean, Aaron Rodgers came back same year.

Brian: Modern professional sports utilize load management, giving athletes more realistic, extended recovery timelines rather than rushing return to play.

Brian: For ACLs or Tommy John surgery, rehab protocols have expanded from 9–12 months to 12–15 months. We are smarter about protecting recovery timelines.

Brian: And in baseball Tommy John surgery used to be 9 to 12 months. Now it's 12 to 15 months. So we like to say that we're getting better at doing things. But what we've really gotten better at doing is talking about athletes coming back faster, but being a lot smarter and having them come back at a much more reasonable rate.

Brian: And overall, we're actually bringing athletes back a little bit slower than we used to. And that's at the professional level. And that's starting to trickle down into the amateur and just recreational athletes as well, where athletes will say like, we'll say it nine months, you're ready to come back from your ACL injury, but you're going to ease into it and that's okay.

Brent: Is that a common misconception? I assumed athletes returned faster now due to improved surgical techniques and rehab protocols.

Brian: It's a common misconception. Biological healing timelines for major soft tissue procedures haven't shortened dramatically, though bone fixation methods allow faster movement for certain fractures.

Brian: So if you have a forearm fracture, you can get it plated and you can come back in four weeks. Once we see a little bit of bone healing and you can play in a cast. So there are exceptions. But for the classic soft tissue injuries like Achilles ACL, shoulder instability, we are much more protective of our athletes. And I think that's multifactorial.

Brian: Teams protect high-value athletes far more today than in past decades, prioritizing long-term career longevity over rushing players back.

Brent: Does recovery time hold true for joint replacements like knees, hips, or shoulders?

Brian: For joint replacements, early mobility and hospital discharge happen much faster now. Surgical techniques are less invasive.

Brian: However, complete physiological recovery and muscle adaptation can still take up to a year as patients relearn proper movement mechanics.

Brian: But your body is still going to recover. And a lot of times what we don't really focus on, let's say for a shoulder replacement, since I do that and don't really do hip and knee replacement, you may not have moved your shoulder normally for a decade before this surgery. So then to say, look, when are you going to be normal?

Brian: Well, I'll clear you to do everything that you want to do at six months, but you're still going to get better because you're realizing what your muscle couldn't do for another six months. We say it's a year recovery, but a lot of that, you're feeling fine. You're doing the things that you want to do. So recovery is faster and we understand a lot more.

Brian: But we also understand that there's a broader spectrum of patients and that some people will say are fast responders, and they kind of get better really quickly and then taper off. And then the other people that are delayed responders where they seem not to be doing very well, and then all of a sudden month for five, six really take off.

Brian: Recovery varies across individuals based on stress, genetics, and rehab adherence. Recognizing individual variation helps set better expectations for patients.

Brian: And that's okay.

Brent: Turning to strength training in middle age: we hear constantly about preventing muscle loss and sarcopenia through lifting weights.

Brent: Yet maintaining a regular routine without injury can be challenging. I developed shoulder impingement working with a trainer and suffered back pain trying on my own.

Brent: How do you view strength training safely in middle age?

Brian: It's both fascinating and complex. I try to exercise every day and that includes some idiotic decisions. Somehow my wife and I ran what's called the Double Dipsy, which is over a mountain from the beach into like a city and then back. So it's a 14.5 mile run. Was I stupid enough to run that on a stress fracture? Yes.

Brian: Strength training is 100% beneficial. Studies show it supports muscle mass, cardiovascular health, and metabolic rate post-exercise longer than steady-state cardio alone.

Brian: And every study shows that some level of strength training is a huge value add not just for our muscle strength, but for our cardiovascular system. And it's a different kind of stress than the typical cardio. It gets you into that zone to kind of prolonged metabolic state. The other thing it does that's different than a straight cardio exercise is it increases your metabolic activity for an extended period afterwards.

Brian: Avoiding injury requires balancing prime movers with stabilizing muscles. Shoulder impingement, for example, happens when the space under the acromion gets inflamed due to poor rotator cuff stabilization during deltoid-heavy lifts.

Brian: And within that space, there is a Bursa or a sack of fluid that allows smooth gliding of your shoulder. When you raise your arm up in order for your shoulder to be functioning correctly. When you raise your arm up, there's this idea of a force couple, and that means your deltoid, the muscle you can feel on the outside of your shoulder, is coupled with your rotator cuff.

Brian: So when you raise your arm up, your deltoid fires, your rotator cuff fires, and it paradoxically pulls your humeral head or the top of your shoulder down and maintains that space, your rotator cuff is like the core of your shoulder. So it's similar to your abdominal muscles and that they're not very big. You don't get a huge cuff.

Brian: Nobody goes to the gym and says, bro, I'm really working out my cuff today so I can look huge. But it's a counterbalance to all the little things you do in your shoulder. Our small core muscles get weak relatively quickly as we get older, and that's multifactorial. It's partially the type of muscle it is. It's got more slow twitch fibers, partially because we're sedentary.

Brian: We spend a lot of our time sitting. We're not using a lot of the little muscles in our abdomen or low back and in our rotator cuff. So when you go to lift and you're predominantly deltoid strong and your rotator cuff has gotten proportionately weak, instead of creating that space that you need, you get a little bit less space.

Brian: Targeted rotator cuff and core stability work prevents these imbalance injuries.

Brian: We do planks all the time. Some people do planks all the time. We do sit ups, we do low back exercises. And that's to strengthen our core. We should just be doing the same thing in our rotator cuff. And then that tends to balance that out.

Brent: Do you advocate for specific styles of strength training, like kettlebells, functional fitness, or traditional barbell lifts?

Brent: That's not great for your shoulders. You can do other things that are going to strengthen your your pecs. And so is there a particular style you would recommend? I assume you would recommend, you know, go really slowly in terms of increasing the weight, but how do you think about it for yourself or advise others?

Brian: Any movement is better than nothing. Starting with basic bodyweight exercises or modified push-ups provides value. Choose variations that feel sustainable for your body.

Brian: They're all going to have advantages and disadvantages. And this is where somewhat where that patient specific thing comes in handy. Some people are going to gravitate to one thing, some are going to gravitate to the others. They're all value added. But within that, you want to think about the exercises that make you feel good and the ones that are going to bring value to you.

Brian: So for me, I can do squats. They make me really saw, so I'd rather run. I'll do a little bit of body weight squats, but as soon as I add weight I can't do it to save my life. My oldest daughter can leg press over 600 pounds, show correct me and say 700 at some point. I cannot do that.

Brian: She is physically stronger than me. If I do that either I feel like my legs are going to come off or I'll be so so where I can't walk for a month. That's just individual differences. So no matter. And I think the other challenge is so one challenge is finding the exercises that you like and that you feel like are doing what you want them to do.

Brian: Variety helps prevent overuse injuries. Repeating the exact same weight movement pattern continuously can lead to localized strain, whereas mixing up exercises builds balanced strength.

Brian: And the variety across different platforms is going to build and maintain load in a much more consistent way than always doing the same thing. And that's where you kind of, I think, get into those overload type injuries where I okay, I've done the same biceps exercise, done three sets of 15 at 30 pounds. I never change how my wrist is, how my wrist is getting a little sore.

Brian: Long head of my biceps. Esau, mix it up and do something else.

Brent: Since you study sarcopenia, doesn't running lack the specific resistance stimulus required to combat heavy muscle loss compared to compound lifts like squats?

Brent: And I would assume that running does not replicate the benefits for sarcopenia that strength training does. And so why is that the right answer for you? What am I missing?

Brian: Direct heavy resistance provides the optimal stimulus for muscle retention, but personal tolerance dictates training choices. Consistently doing exercises you tolerate well is better than avoiding exercise due to severe soreness.

Brian: I do more upper body stuff and then I ride a bike and run. But that is still value added more than not doing anything. And then am I missing out on squats? Maybe. But every time I try it, I'm miserable. So it's everything's a risk benefit profile for me. That's how my body seems to react to weights of my legs.

Brent: How critical are flexibility and mobility routines like yoga for preventing injury?

Brent: Would you agree with that hypothetical? How important do you think something like yoga or some equivalent mobility flexibility is to injury prevention?

Brian: Evidence doesn't show that higher flexibility directly correlates with fewer injuries. Static stretching right before exercise offers little benefit and may temporarily increase injury risk.

Brian: So things that we do know stretching before exercise has little to no benefit. So this pre-war up stretch that we all did in physical education and K through eight probably not beneficial at all, and in some instances may be harmful and may increase your injury risk. Conversely, warming up, going for a really slow jog, and some light kind of plyometric type things before running.

Brian: Dynamic warm-ups before workouts and static stretching afterward are effective strategies. Yoga improves balance and core strength—both essential for preventing dangerous falls later in life.

Brian: It strengthens your core, strengthens your balance. Balance is the thing that gets people in their 70s and 80s. They fall down and you have a hip fracture. That's a life altering event. The better your balance is, the better your. The last decade to two of your life is. But we cannot confirm and say if you do yoga or if you do other flexibility exercises, you are definitely going to lower your injury risk at this point.

Brent: Okay. And then why does stretching before exercising, why would that actually increase risk of injury?

Brian: Aggressive static stretching on cold muscles can strain tendon attachments, making a dynamic warm-up preferable before intense effort.

Brian: All these are relatively minor. It's not like if you stretch, dear God, how did you survive? You've probably torn your hamstring ten times, but it lacks the efficacy that our PE teachers taught us when we were children.

Brent: I mean, I feel like we still see football team pro football teams doing it, you know, as a group before. Before.

Brian: Yeah. But it's it's really chill. And really what they're doing is they're getting out to doing a team activity and then they break off into their little groups and they do their individual warm ups. And oftentimes they've already been out there for an hour and a half before we see them come out as a group.

Brent: Are there sports adults in middle age should avoid? Sudden stops in sports like basketball make me worry about Achilles tendon tears.

Brent: And so is there anything you would say? Yeah, a certain age, I don't know. You don't play basketball anymore. You don't, you don't. You're not a pitcher on the baseball team or.

Brian: If you are passionate about a sport, keep playing safely. While risk profiles shift as we age, staying active offers far more benefit than avoiding activity altogether.

Brian: When I play basketball now, it's rare we have a resident versus attending basketball game, and I play very carefully, partially because I don't want to be the guy that tears my ACL again in front of residents. That's how I retour my ACL was in front of one of our residents and fellows. But I don't think there's necessarily something that you should say absolutely don't do.

Brian: I mean, if I'd say, don't do anything, don't get in a car. The riskiest thing we do every day is get in a car and drive on a freeway. It is much more likely I'm going to have a catastrophic event getting in a car and driving than me. At worst, I tear my Achilles or read tear my ACL.

Brian: That's that sucks. But that's not risky compared to the other things we do.

Brent: What is your perspective on recovery peptides like BPC-157 for speeding up injury repair?

Brian: I await clinical data. While some animal studies show localized blood vessel growth, human clinical trials demonstrating safety and efficacy are lacking.

Brian: So it was improving blood flow. A lot of caveats in that mouse studies are not human studies. Mice are resilient. Humans are not resilient. There has been no clinical trials that have shown any real benefit from peptides. That's problem number one. Number two is where do you put it. So we have patients that will inject it into their incisions post-op.

Brian: Unregulated compounding pharmacies present significant product variability, risks of infection, and banned-substance compliance issues for professional sports leagues.

Brian: And I think one of the scary things, you know, one of my jobs is to run a lab. We have people in lab that are curious about this. So they went to purchase BPC 157 and you had a couple options. We can buy it from the chemical company that makes it, since we are a lab, and this is the era with questionable funding from the NIH, we were looking for discount and you can buy it on Teemu if you can buy the same compound from a chemical supplier.

Brian: And Teemu, you really have to worry about how what you're actually getting with these compounding pharmacies. So I am very skeptical. It is important to note that all professional leagues still ban the substance out of fear of the downstream consequences and the lack of efficacy. Are we looking at it in lab to see? Does it promote anything beneficial in human cells?

Brian: Yes, but the data is not showing anything of interest yet. So I'm pretty skeptical on whether or not we are going to have, at least in the next couple of years of these are the peptides you should take. These are the ones you shouldn't, and these are how and when you should be taking it, which are all really important.

Brent: And what do you think of the, you know, the the patient for you? Or I hear people saying, you know, these miracle stories of somebody had an injury and they used the Wolverine stack or BPC 157 in the Wolverine stack. And wow, they just recovered so quickly. It was amazing. And they're running around espousing that. Do you think that maybe there's some truth to that?

Brent: It's just we don't know what the individuality is. Do you think it's placebo? Do you think it's just somebody deluding themselves? I'm sure you've heard those stories.

Brian: Yeah, I have patients that have said, well, I recovered quicker from this surgery because I took this. And 100% it is possible that there is some beneficial effect if you increase the blood supply to a region that is trying to heal, you know, that's fantastic. You block blood supply. We know things don't heal. So is it possible? Absolutely.

Brian: The placebo effect in medical and surgical interventions is powerful, often showing up to a 40% perceived benefit. Until rigorous human data exists, caution is warranted.

Brian: Like if you pay for it and you feel like it works and it's safe and you don't have a downstream consequence, fine. Whatever gets you better is fine. The risk is still, you get that post-op infection, you've now spent an insane amount of money on it, or it turns out five years from now, what you actually got had carcinogens in it because you bought it from a compound pharmacy that you didn't understand.

Brian: What else went in that medicine. And that's kind of the scary part. And even though the FDA may over regulate things potentially, and make things really slow to come to market, the drugs that we buy out of a pharmacy, we know what are in them, and we kind of take that for granted and extrapolate that across everything. But I really want to know what I'm putting in my body.

Brian: And if I'm not sure, I don't really want to be injecting it.

Brent: Yeah. And what scares me is that our physiology is very complicated. We had a conversation recently. We're talking about horse misuse and antibiotics. And if you take a small amount of antibiotics you're actually going to make the bacteria stronger. You're going, you know. And so that's why we have to take the full course of the antibiotics. That can be true for some cancer treatments.

Brent: And as researchers like, you know, finding new compounds that can get through the clinical trial process is very hard. And so when you're just experimenting on yourself, you're sticking something into a very complex physiology that does not always react for the same reaction you might see in an animal. And there's a whole bunch of unintended consequences. You don't know what you're getting to your point about these compounding pharmacies.

Brent: And so you're really playing with fire in a, in a bunch of different ways and oversimplifying the effect that something will have on this very complicated thing that is the human body.

Brian: Yeah, I couldn't say that any better. Our bodies are incredibly resilient. We have a lot of redundancy in the system, and the idea that we're going to inject one thing and or a stack of three things, and that is all of a sudden going to solve all our problems. That would be wonderful. And historically, time and again in society, when we have found a wonder drug about a decade later, we find the consequences are fairly consequential.

Brian: Stupid way to say it. But this has happened with many, many drugs. The current thing that makes me most concerned are GLP ones. They seem great. We are now saying they cure basically every disease or they really. They are definitely helpful for some people and they definitely lower all cause mortality doesn't mean everybody should be on them. Just for a little tune up before the vacation.

Brian: 100% not. And part of what we'll see are the downstream consequences of limiting metabolic intake, especially if you're limiting your healthy metabolic intake.

Brent: And then lastly, just tell us what you're excited about based on the work you're doing at the lab. I mean, I know you're spending time looking at, I think, muscle regeneration and how muscles are recovering after they've been injured. You're looking at sarcopenia. If you were to wave a magic wand and you could see the results of that work, I don't know, 20 years from now or 30 years from now, what would you be?

Brent: What would you be most excited to look at?

Brian: Yeah, I think there's a lot of things that we have found that I think we're really excited about short term. I think we've found that when, you know, some people may have heard of blood flow restriction or BFR, where athletes use it for recovery, we use it for regeneration in certain circumstances, like after an ACL injury or physical therapy uses it a lot.

Brian: We found that some of the mechanisms behind it are that your progenitor cells within muscle can actually transfer extra mitochondria, your little energy powerhouses, from one cell to another. So understanding mechanistically how some of these physiologic processes work means the next step is how can we enhance that? How can we get these processes to work better. So we're excited to study things like that.

Brian: We're also excited to figure out how we can evaluate different progenitor cells within your muscle, and kind of tweak them a little bit to become more pro or stimulate more muscle recovery, especially as we get older. And one of the really challenging things that you alluded to at the start is as we get older, how do we slow that process of aging?

Brian: We don't necessarily not want to age. We don't want to live forever. But how can we feel better as we age? And a lot of that can be with how do we perturb the system naturally. And we talked about a lot of that already, and this has been said in other podcasts. But if you could tell me that there's a drug that makes me turn over my cells, better, make me feel better, sleep better, be stronger, live longer, and be happier when I live longer, I would take that drug and that's exercise.

Brent: Wonderful. Well, Doctor Brian Feeley, thank you so much for the work that you do and thank you for the time today.

Brian: All right. Thanks a lot. Take care.

Brent: The Life Lab by Death Clock is recorded in Boulder, Colorado, and San Francisco, California. Produced by Patrick Guardino, with music by Patrick Lee, and hosted by Brent Franson, founder and CEO of Death Clock.