Is Isometric Training “Worth It,” New Research on *10 Minutes* of Exercise Per Day, NATURAL Alternatives to Metformin & More, Solosode & Q&As — 498

**Ben Greenfield** (0:00)
My name is Ben Greenfield, and on this episode of the Boundless Life Podcast, is isometric training worth it? New research on 10 minutes of exercise per day, natural alternatives to metformin, and more. Welcome to the Boundless Life, with me, your host, Ben Greenfield. I'm a personal trainer, exercise physiologist, and nutritionist, and I'm passionate about helping you discover unparalleled levels of health, fitness, longevity, and beyond.
Welcome to today's episode of Just Me for this show. Little old me, walking on my treadmill. These are the very special times, I feel like Mr. Rogers when I say that, the special times when I sit down and take off my shoes and put on my cardigan and have a little chat with you. In this case, I tend to cover relevant research, like in the fitness, nutrition, health science realm, that you might find interesting or that might improve your life. Along with today, I'll be answering a few listener Q&A's. If you have a question that you would like featured on the podcast, you can go to bengreenfieldlife.com/498, 498, that's the number of this episode.
bengreenfieldlife.com/498, leave your question. And it might get answered if it's not super stupid or about the strange growth on your right forearm that you haven't been able to figure out for 10 years, in which case you should probably go see your doctor. So that all being said, I'm gonna put one of these in my mouth. This is not a sponsor of today's show. This stuff that I'm, this pouch that looks like nicotine, it's called Set. And it uses seratine, which is like nicotine's kissing cousin. And L-theanine, 80 milligrams of L-theanine to kind of take the edge off. No crap in here in terms of the sweeteners, pretty clean. And it's designed to, as the pouch container says, designed to deliver focus and nicotine-like satisfaction with fewer downsides. SETT, S-E-T-T, a better buzz. Anyways, they're not bad. And now I can be like one of the cool kids doing nicotine, except it's not nicotine. And apparently doesn't have a lot of microplastics and the other type of stuff you get in the pouch. So SETT, there you go. I'll find a link and put it in the show notes. Again, not a show sponsor, but that's what's going to keep me buzzing today. All right. So first thing I wanted to address on today's show is I just got back from snowboarding in Austria. And although I have not been snowboarding too much in the past five years, my legs felt great. Little bit of delayed onset muscle soreness and what you would expect from five days. Of snowboarding, but I attribute a great deal of my ability to just jump right back into that sport and have strong legs without a lot of joint wear and tear due to my habit of isometric strength training. In this case, what I personally do is isometric squats. You might remember these with not so fond memories from gym class or some other setting in which you were forced to sit against the wall or get into a squat position and just hold it until you have lactic acid coming out your eyeballs. And I do isometric squat holds for 60 to 90 seconds on a vibration platform almost three days a week. Typically, when I'm strengthening at home, I'll jump on this thing called a power plate. It's a vibration platform. Drop into an isometric squat and just hold it. Fun fact, I also do isometric squats on elevators. It's just my thing, right? I have these little habits and I figure, you know what? Every time I get on an elevator, I can drop into a squat and hold it. When there are other people on the elevator with me, I don't tend to do this because I don't want people to think I'm taking a dump in the elevator. But if it's just me, I'll drop into a squat. And when the elevator is going up or down, there's a little bit of a gravity component too. So anyways, what I'll do, for example, the gym is like in between upper body sets. I'll just go hop on the power plate, drop into an isometric squat and get a little bit of extra leg training in. Now, the reason I am telling you all of this is I was recently reading the Journal of Strength and Conditioning Research, and it went into a study on whether or not isometrics could improve performance in runners. So first of all, let's get this out of the way. You probably have a pretty good idea of what isometric training looks like based on my description, like holding up position at the bottom of a pushup, split squat hold in a lunge position, wall sit, calf raise hold, pushing against an immovable object like a wall, etc. Basically isometric training is producing force without visible joint movement. So the muscle length stays static, but the so-called neural drive and the tension in the muscle can be pretty high when you're doing isometric training. So what this recent study looked at was holding a position for three or more seconds for 10 to 20 reps. So kind of a unique form of isometric training. And imagine you were going to drop into a squat, you were going to hold it for five seconds, and then you were going to stand up, recover for 10 seconds, and do this 10 to 20 times. That's an example of kind of like the strength endurance that they were looking at in runners on this test. And they found that there actually was a significant improvement in tendon stiffness and running economy. And even if you're not a runner, this is interesting information. So isometrics are going to train maximal motor unit recruitment. Without velocity. So your nervous system is really triggered, but because there's not a lot of, a lot of like ground reaction forces and joint jarring that occurs during isometrics, it can be pre-joint friendly. And what they've found in strength and conditioning research is that you get a lot of force production. You get a lot of joint angle specific strength in the actual angle at which you're holding the isometric position, and you get better stability under load. For someone like a runner, that would translate to less of a, for cuts he took like collapse the hips at mid stance, and better elastic recoil. Now, distance runners, which is who they looked at in this study, distance runners are pretty heavily influenced by running economy. Not just VO2 max for their maximum oxygen consumption, but how economical they can be when moving, right? Can you get from point A to point B? Think about it this way, like burning as few calories as possible, while moving as efficiently as possible. Now, because isometrics improve force transmission, and increase tendon stiffness, like the recoil of the tendon against the ground, they actually did see a somewhat significant improvement in running economy. And the cool part about isometrics is it's not something that adds significant muscle mass and doesn't result in a whole lot of soreness. Like I said, like I'm doing isometrics three times a week, many times during a workout, I'm doing like anywhere from five to 10, 60 to 90 minute squat holds on a vibration platform. So eccentric lifting in which you're actually raising and then lowering a weight, that can create muscle damage and some inflammation and some soreness. And it does work well for putting on muscle, but isometrics create similar tension with a lot less structural disruption. So you can do them more often. So basically the takeaway message here is that I am a fan of isometrics. Don't throw out the other form of conditioning. Isotonic conditioning is what we typically call like standard weightlifting. Another example of a force increasing relative to the speed at which you move would be something like swimming, like water training, where the water is going to push back against you as hard as you push against it. But during a typical week of training, I like to see some isometrics, some isotonics, and some isokinetics scattered in because you're hitting three pretty important parameters of just the biomechanical movement of the body. Thought that was interesting, especially if you're prepping for 5K, 10K, half Ironman, marathon or whatever. Isometrics are a cool way to train, again, without putting on much muscle also. There was another study that was all over the Exercise Science News, a few nerds that follow the Exercise Science News, claiming that just a few minutes of vigorous intensity training could replace, most of the claims were like around 53 minutes of normal exercise. So what was this study? They basically followed about 73,000 participants from a UK biobank study. And instead of having them self-report their level of exercise, they instead measured the actual movement intensity using an accelerometer. An accelerometer is built into most wearables that most people have nowadays, like your whoop, your aura, your ultra human, whatever it is that you use. And what they looked at here was all-cause mortality, meaning risk of dying from anything, cardiovascular mortality, major adverse cardiac events, like a heart attack, and type 2 diabetes. And they wanted to compare how much moderate activity or light activity was equal to a minute of vigorous activity for risk reduction. Now, what they found was that a minute of vigorous activity, and this would be like above what's called lactic acid threshold, you're breathing really hard. You know, what you would think of in terms of like, Sufferfest, this sucks, it's hard, but it's going to be over quick. What they found was that a minute of vigorous activity was the equivalent of about four to nine minutes of moderate activity for reducing mortality risk. And so that of course suggests that vigorous activity is dramatically more time efficient. And they also basically produced headlines that said when it comes to light physical activity, a minute of vigorous activity, vigorous physical activity could replace 53 minutes of light physical activity, meaning a one minute all out sprint on a rowing machine or an air dyne or a treadmill, to replace 53 minutes of just like light walking. Now, there are a few things to realize, even though this wasn't observational and people were actually donning wearables, so they were actually able to measure this directly. That does not necessarily mean that the vigorous activity reduced all cause mortality. It's a clue that it could work, but many people who engage in light activity might be doing light activity because they're like too sick or injured or have some other kind of metabolic issue that keeps them from doing much vigorous activity, because they were just observing these people. They weren't telling them to do certain things. They were just wearing their wearables, doing what they'd be doing anyways. And then they compared things like risk of mortality, risk of diabetes, risk of cardiovascular disease from the data that they actually found. And it was impressive, don't get me wrong, that vigorous activity was so efficient, but it doesn't mean that the light activity is bad or that the vigorous activity was the only reason that people had a reduced all-cause risk of mortality when they engaged in vigorous activity pretty frequently. This aligns with a lot of the literature though that exists when it comes to high-intensity interval training, when it comes to VO2 max, as a very strong predictor of longevity. And if you look at the biggest reduction in mortality, it resulted from around 10 minutes of vigorous activity per day. So we are not talking about like a 40 to 60 minute, like wad, we're not talking about even like a 30 minute spin class. We're literally talking 10 minutes of doing something that is pretty physically demanding on a daily basis. A lot of people can wrap their heads around 10 minutes, like just, you know, walk up that hill as briskly as possible for 10 minutes, or, you know, hop on an air dine and jam through some minerals for about 10 minutes that leave you pretty breathless. So, when it comes to time efficiency, once again, we see vigorous physical activity really winning the day. Now, I should note that previous research by, I believe it was James McKeith, did indicate that once you exceed 75 minutes of vigorous physical activity per week, you actually tend to see increased risk of cardiac inflammation, calcium scores, and atherosclerosis. I mean, you can definitely do too much vigorous activity. If you do the math, 75 minutes of vigorous activity per week, that actually would come out to not really exceeding 10 minutes per day. But if we're talking about truly vigorous, like really up there, close to maximum heart rate, close to VO2 max, most people aren't touching 75 minutes of vigorous intensity physical activity anyways. Like even most people just like lifting weights for an hour at the gym, a lot of them aren't getting close to actual vigorous intensity. But some people are overdoing it. So, sweet spot takeaway message is that 10 minutes of vigorous physical activity per day is very productive when it comes to longevity and definitely more time efficient than both light and moderate training. But remember, the best kind of exercise is the kind that you're actually gonna do. I don't like to all these studies if you go to bengreenfieldlife.com/498.