How to Practice Science-Based Self Experimentation

You like to figure things out by yourself.

You like to test different diets, supplements, and exercise programs, and see which ones work best for you. However, sometimes it’s easy to take your self-experiments too far.

It’s easy to mislead yourself with logical fallacies and poor evidence. In this podcast, Dr. Spencer Nadolsky is going to teach you how to use the best available evidence to practice science-based self experimentation.

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El barzón” by Los Amparito

Do you have any questions about self-testing? Leave them in the comments section below.


**Armi Legge:** If you’ve been interested in fitness for more than about 5 minutes, you’ve heard the term “self-experimentation.” Maybe you’ve also heard the term “n = 1,” which is basically the same thing. Many people make large claims based on their self experiments like calories don’t count or that eating certain foods helps loss or improves health or that certain supplements help you lose fat, think faster, live longer, and do all sorts of other stuff.

In some cases, these people turn out to be right. A lot of the things we now take for granted as true were first tested by athletes, bodybuilders, and other people who were basically just throwing stuff against the wall and seeing what stuck best.

We tend to remember it when these personal experiments turn out to be true. We are very good at forgetting or ignoring when our self experiments are wrong.

Anecdotes are the worst kind of evidence. No matter how many people believe an idea or how long an idea has been around, you still have to make decisions based on good evidence.

The problem is when strong evidence conflicts with your personal experiences. Then what do you do? That’s what you’re going to learn in this podcast.

You’ll hear from Dr. Spencer Nadolsky, a familiar practitioner and former collegiate wrestler who deals with a lot of people who are trying to lose weight, live longer, and be healthier. Spencer is a guy who understands and uses science on a daily basis and deals with a lot of patients who don’t necessarily understand the difference between anecdotes and hard proof.

In this podcast, you will learn how to reconcile your personal experiences with scientific evidence. Spencer and I also give you some simple guidelines for how to use self-experimentation without getting lost in your personal fantasies about how you’d like the world to work vs. how it does work.

My name is Armi Legge and you are listening to Impruvism Radio, the podcast that gives you simple, science-based tips to improve your health, fitness, and productivity. If you like what you hear in today’s show, here’s how to get more like it. Go to, enter your email address in the box on the right side of the page, and click the button below. After you do, you’ll get free updates from the Impruvism blog delivered to your email inbox when they are published.

Thank you, Spencer, for coming on the show today. Would you tell our listeners who you are and what you do?

**Dr. Spencer Nadolsky:** Yep. Thanks for having me on the show, Armi. I’m a resident physician, third year in family medicine, which means that you go to medical school after undergraduate. It’s a four year thing. Everybody learns the same stuff but then you pick a specialty. I chose family medicine. And then you do a residency. So you do even more training to get more specialized.

The way I got there is interesting, though. When I was younger, my dad was a biology teacher as well as a wrestling coach and football coach. My brother, who is four years ahead of me, was really into athletics and he was much better than I was. He got into it at a younger age and I figured I’d be just as good as him, relying on my last name.

Basically, what happened is that when I got to high school, my brother had already been a four-time state finalist, two-time state champ and I bombed. I was awful. I was JV my first year and I realized that I wasn’t going to have to rely on my last name. I needed to actually do something about it. So I got really interested in diet and exercise, which my dad, being a biology teacher and a wrestling and football coach, I already had kind of a background in it so I studied, studied, studied and practiced it.

I was 140 and gained about 40 pounds my first year. Did OK the next year. Gained another 30 pounds and ended up being a state champ. I went from being a JV to a state champion. I put it all into hard work and also a lot of understanding the science of nutrition and exercise.

So I went out to play football and wrestle in college, first at Michigan State and then at UNC Chapel Hill. For my career, I didn’t want to necessarily work with athletes, although I think that would be cool. I wanted to translate that exercise and nutrition science into helping the general population.

So then here I am, trying in a primary care setting in family medicine to push diet and exercise as medicine instead of pharmaceuticals, basically. I use pharmaceuticals if I need to, but mostly diet and exercise if that is a possibly.

**Armi Legge:** Sure. I have to ask. How much did you have to eat to gain like 70 pounds of body mass in two years?

**Dr. Spencer Nadolsky:** It was a lot. At first, I didn’t count calories. Literally at every opportunity, I would try to stuff my face until I was about to puke. It sounds awful but I took it very seriously. It wasn’t like, “Oh, I’m just going to get big this summer” or whatever. It was an every day thing. I was trying to eat as much as humanly possible.

At first, I didn’t really know too much. It was just like Whoppers, huge things of spaghetti or whatever. It didn’t matter what it was. I was just trying to pig out. As I finally tuned it, I got different protein powders and got into different meats and things like that and really understood a little bit better at the time what I should do.

Once I started tracking it, I was trying to get at least like 400g of protein a day, which was ridiculous I know. Then around 5,000 calories a day.

**Armi Legge:** Nice, man. Nice. That’s awesome.

Something we’re going to talk about today is related to that, and that’s self-experimentation. Figuring out what works for you and what doesn’t. It has become a lot more popular recently, especially in the fitness and health worlds. Basically, people are getting exposed to a lot more information, both good and bad, about diet and exercise as you were and I was and they’re testing different methods on themselves.

On the one hand, you have people who are just out there trying a different exercise routine, whether it’s changing from Crossfit to barbell to Spartan, whatever that stuff is, all this different stuff. On the other hand, you have people who are trying to track and quantify every tiny little minutia of their lives almost like a real scientific study. And it seems like many people are placing a lot of faith in their self experiments.

So what are some of the problems people can run into when they are trying to conduct a study on themselves vs. that kind of data against a controlled trial? Like a real RCT?

**Dr. Spencer Nadolsky:** What people have to understand is that an n of 1 self experimentation really only applies to them, and especially they have to be very careful about their variables because there are so many different confounding things. They have to be careful about telling other people what works for them because it really doesn’t matter when you look at the power of all these different trials with thousands of people.

I just wanted to point that out. You have to be careful. You have to say that it applies only to you, number one.

Number two, I don’t think people take into account the right exact variables and then they think they did something when actually they didn’t account for another thing.

For example, a lot of people think that carbs make them fat, so what I’m doing is I switched my macronutrient profile from a high-fat, low-carb to a high-carb, low-fat with keeping protein exactly the same.

One of the things I’ve noticed is when I’ve done this in the past, just said I’m going to increase carbs, I was increasing fat at the same time just not in an isocaloric manner. What I’ve noticed is if people don’t track it correctly, they don’t account for those types of things. So it’s very important they understand that.

Also, people before getting into this, especially if they start getting into lab testing, they have to understand the implications of those labs. It’s usually best to do it under the care of an informed healthcare professional. Otherwise, people can freak out about certain labs that may have just been an error. I think that’s really important as well.

**Armi Legge:** Let’s talk about the lab testing a little more. When people think of self-experimentation, they start picking up Tim Ferris’ books and they look at all these other things telling people to get this plethora of scientific tests and blood tests. What are some of the big problems people can run into with that?

**Dr. Spencer Nadolsky:** I’ll just do a personal story. I bought a few glucometers in the past, just experimenting on how this meal affects my blood sugars and what my fasting blood sugars were. Not for any real purpose other than for just having fun. Well, the first glucometer I got showed that I was basically prediabetic, which didn’t make much sense when I was 7% – 8% body fat and an athlete.

So I started freaking out. I had to get a bunch of other tests. What ended up happening is that a year later, I got a letter in the mail saying, “Your glucometer has been recalled because it was faulty. It was showing people very high levels of glucose.” You know, 10% – 20% higher than what it should have been.

One of the things you have to do is be informed of what you’re actually testing. This is why in medicine, people get mad at doctors for not ordering certain tests. What they have to understand is there are certain probabilities and positive and negative predictor values that we’re looking at, sensitivity, specificity based on certain symptoms and conditions that we’re taking into account. So if you look for things that are likely not there, there’s a possibility of it being positive and then you have to go down this rabbit hole.

One of the sayings that the doctors say is, “Be careful what you order because you might find something.” It sounds ridiculous but all of a sudden you start looking for things that are likely not there and it’s a false positive and you go down this rabbit hole of ordering a ton of expensive tests causing a lot of worry. It’s similar to a lot of breast cancer screening and types of things like that. They just have to be informed and understand that concept.

**Armi Legge:** Right. So basically what can happen is you end up finding results that appear to mean something but really may not and it basically gets people really stressed. They spend some money on the testing and it doesn’t really bring them much health or happiness.

**Dr. Spencer Nadolsky:** Exactly. Other than stress.

**Armi Legge:** Right. So what are some tests that you do feel like are probably warranted for people either pursuing weight loss or muscle gain or just general health?

**Dr. Spencer Nadolsky:** If I had it my way, I would definitely get a battery of tests before try to lose weight just to check and screen for something things. For guys and women, blood sugar I think is important. Same with a hemoglobin A1C, which is basically an average blood sugar over 3 months. Your blood cells get this glycation that they measure. It shows an average of your blood sugar. You want to rule out secondary causes of obesity with looking at thyroid, although it’s actually not very common.

But other things you want to make sure of. For guys, you might want to look at total testosterone but I will say you have to be careful of that. I see a lot of these gurus on the internet talking about, “Oh, got to get your testosterone checked because if it’s not over a certain level, you’re not going to have any results and blah, blah, blah. You have to go on testosterone replacement if it’s this level or that level.”

They don’t realize that can vary so much. I’ve seen guys with levels around 1,000 vs. levels around 400 where the 400 guy looked way different than the guy with 1,000. You got to look at some of those things just like I was talking about.

Other tests… sometimes you look at fasting insulin. Sometimes you can do like a dynamic test, doing a glucose tolerance test if you’re looking for insulin resistance, checking your blood sugars after an overload along with an insulin, so kind of a dynamic look.

Some of the stuff I’m looking into is now getting a fasting lepton and adiponectin level. It’s kind of a research type of test but now I think it’s starting to become more readily available, at least with some of the labs I’ve been working with.

**Armi Legge:** So what do you think of these private testing companies like 23 and Me?

**Dr. Spencer Nadolsky:** That’s a genetic.

**Armi Legge:** Yeah. There’s some other one that’s like a new blood testing things. You pay $2,000 or something and you get these massive panels. There’s Direct Labs, I think. What do you think of these, where people are often getting a lot of tests without their doctor’s input and trying to interpret those?

**Dr. Spencer Nadolsky:** It’s called Direct Access Lab Testing. They tried to come out with a more commercial way in like Walmart and places like that because they thought people would be really interested in their own health. It turns out most people aren’t. The people on the internet are, though.

It’s a different population. People in my clinic who I see, the general population, sometimes they leave without getting their labs because they don’t want to know, they don’t want to get their blood drawn, they don’t care. A lot of these people on the internet will do it.

What I’ll say is kind of the same thing. I see people ordering all sorts of different testosterone tests and all sorts of things related to that. These different neurotransmitter tests. Without context, they mean nothing. Sometimes, you can find something very egregious but they probably had symptoms related to that, so I would just say be careful. is where you can just go and you can order basically any test you can get at a lab corps. 23 and Me is a place where you swab or spit in a tube and they look at some of your genetic coding. I did one of those before just for the heck of it.

There are some important things that you find in there, but I actually work for a place called that’s kind of the same thing. You get a huge battery of labs and you can talk to a person like me to go over the labs.

Like I said before, just be careful. I know people are coming to me on the internet after they get these labs like, “What does this even Mean?? Oh my gosh, am I going to die?” Hold on a second, why did you even get that? I would be careful definitely.

**Armi Legge:** Two of the tests people often get most excited about are thyroid and testosterone. As you mentioned, there can be a lot of variance in testosterone levels and how those actually have an impact on people’s health.

What I’ve heard, and I haven’t done enough research on this to have a very well informed opinion, but just talk to some of the other people I know who are trained in this stuff, it sounds like there really isn’t a good indication of what a normal or healthy testosterone level is and that there can a lot of variance without really any impact on health and they’re not sure whether raising that above normal levels is good or bad or really does much of anything. So what is your take on that?

**Dr. Spencer Nadolsky:** I wouldn’t just screen the entire population with a total testosterone. First of all, when you screen for hypogonadism or low T, you want to get at least two morning total testosterones to really confirm it. Generally, you look at the lab value and there’s a bottom of the normal, which can be like 300 or 250, around there. But you also want to correlate it with symptoms. Because if somebody is not feeling bad and you just checked it, does that really mean that they’re hypogonadal? Maybe they feel fine and have no issues with it.

The other thing is you want to make sure there are no secondary causes of it. So what we see a lot is this obesity-related secondary hypogonadism. Basically, where they have a kind of metabolic syndrome type picture with insulin resistance and abdominal obesity. Basically, it’s causing their hypothalamus, pituitary, and gonads not to communicate well.

So if you just checked the total testosterone and you saw that, it would probably be low and they might have symptoms and you say, “OK, let’s give you some testosterone,” that’s a problem because you could help them lose weight and they would generally normalize when you look at these studies.

It has been shown that some of these people with hypogonadism and low-testosterone do have some increased mortality but we don’t know whether supplying these people with testosterone necessarily helps. It is theoretical but it might help. You want to find the underlying cause, definitely.

For thyroid, that’s something some people say they should screen for and the screening test is a TSH, or thyroid stimulating hormone, which comes from your pituitary and basically tells your thyroid to work. If that number is high, it’s screaming at your thyroid to work harder. You have to be careful with that because that can vary as well.

I just saw a few people where they have somewhat high TSH and all of a sudden, if you go ahead and put them on thyroid medication right there, they have to be on it for the rest of their life, theoretically. However, if you tested them again in a month like I’ve done a few times, it normalizes. There can been transient changes. You have to be careful what you’re testing for.

Hypothyroidism is somewhat prevalent. If you have any of the symptoms, I think it’s worth checking into. Also, the TSH isn’t necessarily the only test. It’s a decent screening test but if it’s at the higher end of normal, you may want to look at the actual thyroid hormones, the free T4 and free T3.

This is why working with the doctor is important. You want to know the symptoms and lab values as opposed to just getting these lab values and not even taking into account the patient, basically.

**Armi Legge:** That’s one problem we’ve talked about before: interpreting thyroid tests. You’ve talked about how a lot of people on the internet just really don’t know what they’re talking about. So what are some of the common misinterpretations of thyroid tests that people make?

**Dr. Spencer Nadolsky:** It goes along with this TSH. A lot of people are like, “Well that’s not a very good indicator.” It’s a decent screener, but what a lot of these people are finding is that if they do get the T3 and T4 and if it the T3 is low and they think that they need to go on some hormone– but you want to look at the underlying cause, just like the hypogonadism and low testosterone. Some of this might be obesity related. Some of it might be metabolic syndrome related, some of this inflammation.

The most common cause of hypothyroidism is Hashimoto’s thyroiditis, an autoimmune thyroiditis. So if you really think you have this autoimmune thyroiditis, I would definitely get thyroglobulin antibodies and also TPO antibodies, thyroid peroxidase antibodies. Because if those are high and you’re having symptoms and your thyroid levels are a little bit off, then you’re more likely to treat it but I’ve seen some of these people who just go, “Oh, I have low T3, I better get some Armour or some Cytomel or whatever.” And they start treating it and it’s like whoa, whoa, whoa. You bypassed the underlying issue. You might have been sick. You might have had other things at that one time that affected your labs. So it’s a problem. Everyday, I see it.

**Armi Legge:** Sure. We talked before about how many of your patients you work with are pursuing weight loss. They need to lose weight. What often seems to happen is people have low testosterone or low thyroid or whatever problem. They’re overweight and they assume at least part of the reason they’re overweight is because of these results when in fact it could be the converse. The reason the problem is present is because they are overweight. How do you talk to somebody like that and help them understand that before they need to do a bunch else, they should probably focus on weight loss?

**Dr. Spencer Nadolsky:** So one of the things is that when it comes to some of these, some people believe just give them the hormone it will help them. Which it can help them but in the long run, do you want people to be on the hormone forever? There are side effects of that. Or you can put them on it and maybe ween them off as they lose weight and do a diet and exercise lifestyle program.

I don’t know. I like to push the diet and exercise. I generally draw a picture for these patients and they tend to get it if I draw a picture and really explain the mechanism.

The general population patients who come in just go, “Oh, OK.” They don’t really pay attention and it’s kind of hard. But the folks on the internet really start to get a grasp of it when you start showing them studies and drawing a picture for them. They end up understanding. I say, “OK, this coming from your brain is getting disrupted because of this over here. So you don’t want to just throw gasoline at this kind of thing.” I don’t know.

For example, sleep apnea. You get patients who come in with low testosterone and all sorts of different things and they also snore. I’ve seen this happen. People just throw testosterone at them because they’re like, “Oh, they’re hypogonadal. Their testosterone is low.” If they would have looked further and found the underlying cause, they have sleep apnea that’s disrupting their whole hypothalamic pituitary adrenal axis along with their hypothalamic pituitary gonadal axis. And if you give them a CPAP machine to help them lose weight, all of a sudden their testosterone normalizes and they feel a lot better.

Sometimes people think the testosterone can make the sleep apnea even worse. That’s kind of controversial, but either way. So it’s important to know the secondary costs.

**Armi Legge:** Sure. So how do you basically use self-experimentation while maintaining scientific credibility and maintaining an evidence-based practice? How do you balance the benefits of both?

**Dr. Spencer Nadolsky:** It’s tough. So right now I’m doing my own kind of self-experimentation and I’m trying to keep it as scientific as possible, but it’s quite tough. It’s not like I have unlimited funds to make it as controlled as possible. I’m trying but just knowing that it’s an individual thing . . . I don’t know. Just knowing that whatever you do is not going to be like a controlled trial unless you’re a robot, basically.

**Armi Legge:** So basically just setting reasonable expectations and understanding this isn’t really that scientific but it’s still helpful.

**Dr. Spencer Nadolsky:** Yeah. And it’s individualized for you. Maybe you start finding out things that work psychologically and behaviorally as opposed to in a robotic fashion, I guess. If that makes sense.

**Armi Legge:** Why don’t we talk a little bit about your self experiment. What are you changing and what are you trying to get out of it?

**Dr. Spencer Nadolsky:** For the past 7 years or so, after I was a heavyweight at UNC for their wrestling team, I was like 260 some pounds. I said I don’t need that many carbs anymore because I’m not involving myself in highly glycogenolytic sports like wrestling. You need glycogen if you’re going to wrestle. I figured I’m just going to be weight training and I want to be lean, so I’d go on a lower carb, higher fat, higher protein diet since I don’t need the carbs and it would be easier for me to stay lean.

I did that and I lost like 40 pounds throughout the past 7 years and have maintained around 220. I thought it was great. Well, looking at a lot of your work and Alan Aragon’s and some of these other folks, I was like, “You know what, it is interesting. I don’t think carbohydrates are the root of all evil. Let me see how my body responds to it.”

I literally switched the macronutrient percentages. I kept protein the same. I tracked my calories and macronutrients for a week. Kept the protein the same and flip flopped the calories from carbs and fat. So I was at a very high fat percentage. I can’t remember. I have it on my blog, but I literally went from like 100g or so of carbs to 300g overnight.

Some people are like, “Whoa, why’d you do it so quickly?” Well, why not? Let’s see if there’s really any issue going on here. I was very careful about tracking it. That’s why I say if you do this, it’s very important to be somewhat scientific about this. I have been very careful, weighing everything out and looking at it.

It’s been about a month and I’ve actually had to ramp my carbohydrates because I started to lose too much weight. We could theorize about why that happened but now I’m at 360g of carbs per day. I actually got super advanced lab testing done. I had a few lab tests while I was doing the high-fat, low-carb, and after a week or so of doing the high-carb, low-fat, I got some more lab tests.

It’s quite interesting because some of those things that were actually kind of high and in the abnormal range, like my LDL particle number during the high-fat was actually cut in half after literally a week of this high-carb, low-fat.

To top it off, people think that carbs will make you fat. Well, in my case, like I said, n if 1, this doesn’t necessarily mean everybody. Keeping my protein the same and switching my fat to carbs, I have improved my stamina and endurance in the gym. I do mostly resistance training. Instead of doing 315 on the bench press like 6 times for a set and then all of a sudden I can’t do as many in subsequence sets, now I’m able to just pound it through the whole workout.

My endurance in the gym has been awesome. My performance has gone up. My energy levels are great. I haven’t gotten fat– yet. I lost a little bit of weight at first. I increased my glycogen a little bit, I assume. I increased my water weight at first and then it kind of fluctuated, went down. I kind of trended downwards. I just recently started trending upwards as I’ve increased my calories just a little bit. And now I’m staying about the same at 360g of carbs.

It’s an interesting thing. You have to track it very carefully. I think that’s where most people go wrong when they try to add carbs back into their diet. They just add carbs, add more calories. Which, if you’re scientific and logical, that will lead to weight gain.

**Armi Legge:** Sure. So that actually brings us to another thing that you should definitely know about and that’s supplements. One of the things that people experiment with possibly the most is supplements. What are the problems you see people making when they are choosing which supplements to test and when they are testing them?

**Dr. Spencer Nadolsky:** So supplements should be considered, in some regards, as pharmaceutical. Just because they’re supplements and may or may not be natural, that doesn’t mean that they’re safe necessarily. If they’re actually doing some true benefit, then they might have a same type of a side effect profile as a pharmaceutical job. I think you just have to be careful what you’re picking out. In general, most things are relatively safe.

One of the things is we have a product called glycosyl. It has berberine in it. It’s a super powerful antidiabetic supplement and people experiment around with it. I have some of my patients who get off their diabetes supplement using this supplement, so if it has this pronounced of an effect on your blood sugars and things like that, there could be other side effects. It’s pretty safe but it’s basically like a pharmaceutical. So anything that folks are trying– like DHDA.

I’ll tell you a little tidbit. I did this little salivary test and it showed I was a little low in DHEA. And I was like, “Well, let’s see what happens if I add just a tiny little bit back.” This was earlier this year. I was just messing around. I shit you not. I got gynecomastia. I thought it was such a small dose and so far down the pathway. Yes, it can eventually convert into maybe a small amount of estrogen, but I couldn’t believe it. I took it out and it went away. So people just gotta be careful about what they’re messing around with.

Some of these other things… there are prohormones out there that people are messing around with because they’re basically designer steroids. Most of them are banned as far as I know, but people don’t realize that those can have some major adverse effects on your body as well.

**Armi Legge:** Right. So when you are looking at supplements to try yourself or to potentially develop, what kind of evidence do you look for in terms of randomized controlled trials and that sort of thing?

**Dr. Spencer Nadolsky:** A lot of these things don’t have the money to run these trials. A lot of the stuff comes out of China and that’s where we saw this berberine stuff. It was in the Journal of Endocrinology back when I was in medical school.

When you’re trying to design something, you really want to have at least a small trial in humans. There are so many rat studies that things increase testosterone up to 500% and people go crazy about it and market the heck out of it. Other things that might show small changes in leptin and other stuff like that. It’s just bogus supplement and marketing crap out there.

If you’re going to design something, I would hope that there was at least a small trial in humans to look at it and hopefully there’s safety data along with the efficacy. Sometimes you’re not so lucky, but generally, that’s why there are certain staple supplements out there that get used the most. Fish oil, creatine and things like that have a lot of data behind them. You can look at the evidence right there.

Some of these other obscure things, they use these weird chemical names and literally just make up stuff, these companies do.

**Armi Legge:** So speaking of that, where can people learn more about your work and everything else you do?

**Dr. Spencer Nadolsky:** My internet blog and store is Where I’m doing my self-experimentation is at and it’s basically a site for fitness professionals and internet fitness gurus to learn about medical information from me, who they hopefully consider a trusted source. Basically, there’s so much junk out there. I’m trying to push trusted, good knowledge out there since there’s so much bad stuff.

Also, if you want to learn more about supplements, I’m also the medical editor at I help look at their articles and make sure from a medical standpoint that they fit the bill.

**Armi Legge:** Awesome, man. Thank you so much for coming on the show and I will talk to you soon. You’ve been awesome, man.

**Dr. Spencer Nadolsky:** Cool, man. I appreciate you having me and hopefully you can get me and my brother back on to talk about maybe statins and dementia and myopathies.

**Armi Legge:** That will be a good one, man. I have a feeling we’ll get a few comments on that one.

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