Fit For Purpose: Dr. Mike Israetel's Take On Fitness and Nutrition Science
In fitness and nutrition circles, Dr. Mike Israetel — and his business Renaissance Periodization — has become more and more celebrated over the past decade or so. His bald head and super-jacked physique make him easy to spot on social media, and his studious, academic approach to building the body has seen him gain a ton of dedicated followers. Where did Dr. Israetel come from, though? How did he build his business, and what are the core concepts of his philosophies?
The intersection of science and real-world application
Dr. Israetel holds a Ph.D. in sport physiology from East Tennessee State University and is a former professor of Exercise Science at Temple University. His academic background, combined with his practical experience as a competitive bodybuilder and Brazilian Jiu-Jitsu athlete, give him a unique perspective in the industry.
To Dr. Israetel, fitness and nutrition is all about the intersection of science and real-world application. In 2015 he used his expertise to co-found Renaissance Periodization, a business which offers meticulous fitness training and diet programs to its clients.
Escaping the Soviet Union
Dr. Israetel was born in Moscow, Russia, in 1984 but when he was seven years old his parents moved the family to the U.S. in search of a better life. He wound up growing up in Detroit, where the family was matched with a local Jewish family who showed them the ropes of American life.
In 2017 Dr. Israetel told The Detroit Jewish News, “My family and I will be forever indebted to the Metro Detroit Jewish community for welcoming us from the former prison that was the Soviet Union.”
Meeting his kindred spirit
Dr. Israetel told JTS Strength that the path to Renaissance Periodization began way back in college in Michigan, which is where he first met fellow fitness freak Nick Shaw. He revealed, “We met in the weight room and began to train together, along with a group of other guys I’m still honored to call some of my closest friends.”
He continued, “Nick and I were both kinesiology majors and had a passion for powerlifting and bodybuilding. We also both had a passion and profound respect for the scientific approach to training and nutrition.”
He has no time for self-styled fitness “gurus”
Dr. Israetel and Shaw bonded over their shared belief that science was the only true path to building their bodies — and that bond stayed strong even in the face of people pushing contradictory ideas.
He said, “As personal trainers in NYC several years later, we ran into all sorts of people doubting our methods and willing to give us free advice on diet and training — advice backed only by the name of some guru or another. All of these gurus without a single relevant academic qualification to their name!”
Competitors were peddling underwhelming diets and fitness programs
Of these so-called gurus, Israetel was adamant that most of them were simply “lucky enough to have trained a famous pro and gone on to snowball clients and fame from there.” At their core, though, he believed most of them were snake-oil salesmen.
He argued they were “charging all sorts of crazy money to write diets and programs that were, to put it softly, underwhelming in their validity and level of advancement.” Dr. Israetel and Shaw felt they could do better, but they still found themselves going their separate ways for a while.
Time to incorporate
“I left NYC in 2010 to begin my Ph.D. program, and Nick started his own training company,” explained Dr. Israetel. “He did very well, but eventually both of us were referring each other so often to clients — often due to individual time constraints and Nick’s physical presence in NYC to train my diet clients — that we decided… it was time to incorporate.”
Yes, the time had come for the two friends to go into business for themselves. They knew what they wanted to offer, but what would they call their pioneering new venture?
Why Renaissance Periodization?
Renaissance Periodization wound up getting its moniker for two reasons. As Dr. Israetel explained, the first inspiration came from the Renaissance period — as he put it, a time which saw “an end to the mysticism of the Dark Ages and the rebirth of science.”
The second reason, though, was based on their business model being “an attempt to reflect the practices of Renaissance Technologies — a hedge fund that uses mostly quantitative trading and has largely disposed of trading by hunches and traditions.”
Head science consultant
When it comes to the breakdown of labor, Dr. Israetel is very much the “science guy” of the operation. He revealed, “I wrote much of the early programming and the templates, most of the tracking programs, and things of that nature. I also still do most of the research into effective strategies and am the outreach person on science matters for the company.”
He joked, “That’s why I have this fancy ‘head science consultant’ title, you see! Outside of the research and template making, I do write programs and diets myself as well.”
What does the firm offer?
Speaking of the company’s programs and diets, it offers a wealth of resources to its clients. With membership, you gain access to a host of templates to help you gain muscle or cut weight, and you can opt for a one-on-one coaching package with one of 30-strong team.
On top of that, you can download a huge number of e-books — including healthy cookbooks to help you eat right alongside your training — and you can even buy branded clothing to wear at the gym or at home!
Glowing reviews abound
Over the years, RP has carved out a thriving niche in the fitness and nutrition market — and glowing reviews can be found all over the web. According to the Modern Athletic Health website, “To say RP is comprehensive is a huge understatement, regardless of what service you are looking to get into.”
It claimed, “On week three of our program, our user has lost 4.2 pounds and retained all of their strength… The diet program is one of the easiest programs we have ever followed and most importantly, it is super-flexible and guilt-free.”
Dr. Israetel doesn’t believe in lean gains
Over the years, one thing that Dr. Israetel has been almost fanatical about is debunking the many myths and misconceptions that exist in the fitness and nutrition industries. For example, many trainers will preach about “lean gains” — the idea you don’t need to bulk up before you add muscle and can instead stay lean all year round.
Dr. Israetel is adamant that science has repeatedly proved this is untrue. He claims anyone who advocates this approach must be a “genetic freak” or lacking in musculature.
How to increase muscle
Dr. Israetel told JTS Strength, “Because muscle is best grown in a hypercaloric environment and fat is best burned in a hypocaloric environment, muscle gain and fat loss need to be somewhat distinct phases.” In essence, you pile on the pounds initially before you convert them to muscle.
He said, “You need to get a bit fatter in the short term and burn the fat off later to get the most muscle size. If you try to stay lean all the time, you’re just not going to make the biggest progress.”
You can’t add muscle super-quickly
By the same token, though, Dr. Israetel also disagrees with “experts” who claim you can add muscle super-quickly. He believes 1 to 2 pounds of additional muscle added every week is attainable for most people.
In contrast “gains that are any faster — or gains that are attempted for a longer continuous stretch than about 3-4 months at a time — lead to a vastly disproportionate rate of fat addition, rather than muscle growth.” What exactly does this mean, though?
Gain too much, too quickly, and you actually risk losing muscle
“If you try to gain 3 pounds of weight per week for 12 weeks or 1 pound per week for 36 weeks straight,” argues Dr. Israetel, “you’re going to put on some muscle.” But you’ll also “get so fat that the fat-loss phase to follow is going to take way too long and risk too much muscle loss.”
This will in turn lead “to a slower average rate of muscle gain than the more moderate methods.” On top of that, this tactic can also be truly terrible for your health, and Dr. Israetel wouldn’t recommend it at all.
There are no shortcuts
Most of the shaggy dog stories perpetuated in the industry tend to involve an “expert” saying they’ve found a way to game the system. In business, they’d be peddling “Get Rick Quick” schemes; in fitness, they’re selling magic techniques that claim to improve your body and health almost overnight.
As Dr. Israetel states, though, “Those of us who have committed ourselves to the deep study of this field have come to the realization that there are no shortcuts, just slightly better ways of getting slightly better results.”
It will take time
“Time still has to be put in,” continued Dr. Israetel. “I swear everyone is looking for a weird technique correction that adds 50 pounds to their squat or a food they can eat that just zaps body fat, and they are going to spend lots of time and possibly money in an almost completely futile effort.”
Instead, the truth is simple. “Train hard and smart, eat well, and try to get a bit better every month. After a while you are a completely different person, but it takes time.”
Hypertrophy
In terms of his philosophies, Dr.Israetel is a pioneer in hypertrophy; his extensive research is advancing our scientific knowledge of exactly how a muscle grows during resistance training. In essence, that’s all “hypertrophy” is: building muscle through tissue stimulation and repair.
As Men’s Health magazine’s Annie Hayes put it, “On paper, the principle is straightforward. Lift progressively heavier weights, eat a calorie surplus, get adequate rest, and your body will build larger, stronger muscles to cope with the ever-increasing loads.”
The hypertrophy hierarchy
In terms of fully optimizing your gym sessions, Dr. Israetel subscribes to a three-tiered hypertrophy hierarchy. On his YouTube channel, he tells prospective bodybuilders that he sees his hierarchy like a pyramid.
He explains, “The baseline layer being the most important, the second layer being the second most, and the top layer being the least important, but the sort of cherry on top.” The base layer is the bedrock of everything, and it’s the technique you use for every repetition of an exercise.
Technique and relative effort
Dr. Israetel explained, “Your technique is the plan for how you’re going to execute each rep, and because you plan to execute each rep in a certain way… that plan should be the most to get out of each rep.”
The second layer of the hierarchy is “relative effort” — or, in other words, how hard you choose to work with each repetition. In this way, “Technique is the guidance trajectory of where you shoot your rocket and relative effort is how much rocket power you boost behind it.”
The mind-muscle connection
The third tier of the hierarchy — in Dr. Israetel’s opinion, the least important — is the “mind-muscle connection.” This relates to the psychological effects your exercises are producing, including “how much tension are you feeling, how much pump, how much burn.”
The expert believes this is your body telling your mind whether the technique you chose is working well, or whether it needs to be adjusted. He said, “This mind-muscle connection… grooves my technique into an even better position for more stimulus and less fatigue.”
Cheat reps are a big no-no
There is something that is 100 percent not part of Dr. Israetel’s hypertrophy hierarchy, though: the “cheat rep.” This is when someone sacrifices technique at the end of a set of reps, in order to pump out a few more before they get too tired.
For example, if you’re doing bicep curls, you can lean forward slightly and then rock backward. This will help you lift the weight, no doubt, but your momentum did most of the work, not any true muscular effort.
Always prioritize technique
After years of research and practice, Dr. Israetel has concluded that cheat reps will not help anybody actually gain muscle. He questioned the philosophy, asking, “Why would you let your technique — which is your number-one priority — slip?”
Then he scoffed, “Let me get this straight, you’re saying that the trade-off of the… most important thing… is worth more of the second priority — which is reps in reserve, relative effort? That doesn’t make any sense. Technique is the most important thing.”
Even if you feel the burn while doing cheat reps, it won’t build muscle
According to this scientist, sticking to tried-and-tested technique “makes sure that every rep is high quality. If you expand the number of reps you’re doing by degrading the quality of the reps, the question could be asked: ‘Why don’t you just keep doing high quality reps?’”
Dr. Israetel believes inexperienced people think they’re still building muscle when doing cheat reps because they’re feeling the burn — but it’s all in their heads. He insisted, “Countless studies have shown that the mind-muscle connection isn’t ultra-super important to training.”
Controlling the eccentric
In weightlifting, lowering a weight when doing bicep curls, or when you get low for a squat, is known as the “eccentric.” Dr. Israetel teaches that an ability to control the eccentric is vital in building muscle.
He believes people forgo important gains by simply letting their weights drop, instead of steadily lowering a weight with perfect form and control. It isn’t a complete no-no, but it means you lose out on a chance for big gains and increase the risk of injuring yourself.
Most of your reps should look the same — but not necessarily identical
Dr. Israetel revealed, “That’s a big part of really good technique. Unstable exercise is much more injurious than stable exercise.” The aim is for consistent repetition — or, in other words, “Most of your reps should look about the same.”
Still, he did temper that slightly by saying your reps don’t necessarily need to look identical. In fact, “There’s actually a little bit of an injury-preventative benefit from exposing yourself to slightly different bar positions. It makes you more resilient.”
You might as well collect all the coins on the way down
In scientific terms, “The eccentric actually requires less nervous system stimulus to do the same amount of physical work, which means its inherent stimulus-to-fatigue ratio might be higher.” Basically, you’re exerting less effort to control the descent, but you’ll still build muscle.
Because of this, it only makes sense to do whatever you can to maximize the eccentric. Using a video game metaphor, Israetel observed, “It has to come down, and you might as well collect all the coins on the way down.”
Know when your body needs to rest
Speaking of the stimulus-to-fatigue ratio, Dr. Israetel is a huge proponent of knowing when your body is too fatigued to build muscle and needs to rest. In fact, he’s talked about it extensively on his YouTube channel
He suggests, “If you have… gnarly consistency and you’re kind of burning the candle at both ends and it seems like the harder you work the more ground you lose?” Then it’s time to back off. In his world, backing off means, “De-load every few months.”
Don’t be afraid to de-load from time to time
What is a “de-load,” you might ask? Well, he explains, “Take an easy week of training, or no training at all.” He adds, “If you think you are overdoing it… slice everything in half. Cut all of your volume in half.”
Expanding on this theme, he says, “You typically do ten sets of legs, now you do five. Do that low volume for a few weeks. You might actually start getting better gains right away.” It might sound counterintuitive that doing less will lead to more gains in this scenario, but the science does add up.
Recovery time is vital
During an interview with Stronger Experts, Dr. Israetel explained how it’s all about mesocycles and annual volume manipulations. He said, “In bodybuilding training, you have multiple mesocycles — like month- or two-month-long periods between de-loads, where you’re pushing it hard.”
If you vary your training every few months and lower the amount of stress your body is under, it can “recover a little bit in a different way — just basically recover from the staleness of doing this super-high volume.”
If your training program is always the same, you’re doing it wrong
Dr. Israetel then gave the example of the varied training regimens professional sportsmen use to keep their bodies in tip-top shape. He explained, “In team sports — competition sports — you’ll have dedicated low volume blocks, like strength blocks, power development blocks, to give you a break from higher volume.”
These blocks will “re-sensitize your body and allow you to break down a lot of fatigue.” He concluded by saying that, if your training program looks exactly the same every mesocycle, then you’re doing it wrong!
Basic nutrition is mostly common sense
When it comes to nutrition and diet, specifically in regard to people trying to build muscle, Renaissance Periodization’s holistic approach can be incredibly valuable. When he spoke to Stronger Expert, Dr. Israetel outlined that, when applying the right diet for the right job, it’s mostly common sense.
Just as with training, there are no shortcuts. He explained, “If we’re trying to lose fat, or gain muscle, or enhance performance — calories, or calorie intake, are our number-one consideration.”
It’s all about calorie intake versus burning it off
“If you want to gain muscle, a hypercaloric diet — you eat more calories than you burn — is number one,” continued the boffin. “If you want to lose fat, a hypocaloric diet — less calories than you burn — is number one.”
Unsurprisingly, following these obvious principles count “for probably 50 percent of diet success.” He then poured scorn on the fad diets that take up a lot of oxygen in both the weight-loss and bodybuilding arenas. In fact, he claimed most of them are lies.
Proper nutrition is about calibrating your intake of three macros
“If somebody tells you, ‘You can eat all the food you want but you’ll lose weight’ — that’s [wrong],” said Dr. Israetel. “If somebody tells you that you don’t have to stuff yourself and you’ll get as huge as possible — that’s also [wrong].”
To this expert, proper nutrition is as simple as calibrating your intake of three macro-groups: proteins, fats, and carbohydrates. Protein is the most vital, as it helps build, repair, and maintain muscles as the body loses fat.
You also need carbs and fats
Next, you have carbohydrates, which “fuel the demands of your training, to allow you to recover, and also probably to stimulate muscle growth as well.” He recommends taking them as you need them — for a 200-pound man, for instance, anything between 200 to 600 grams of carbs every day is a good amount, and it has to be matched to exercise.
The third macro — fats — are interesting, though. Because they aren’t needed to fuel athletic function like protein and carbs, many may think they’re bad. But, as Dr. Israetel explains, “A minimal amount of them supports hormonal function.”
A lot of good can happen with the right fat intake
You see, if you exercise intensely but don’t replenish your fats, your body will start to rebel. As Dr. Israetel stated,“It won’t do anything you want. So, a minimal amount of fats, probably 0.3g/pounds/day is a good idea.”
He elaborated, “So, for example if you’re 200 pounds, that’s 60 grams of fats. You go much lower below that, not much good happens. If you stay above that figure, and you just add it, a lot of really good stuff happens.”
Competitive bodybuilding is also a passion
Overall, it’s clear Dr. Israetel knows his stuff when it comes to sculpting the physique you desire — and that’s what he has dedicated his private time to, as well. In 2021 he placed second in the NPC Masters USA Championships super-heavyweight division, which meant the world to him because he’s been bodybuilding for a long time.
As he admitted on the Revive Stronger podcast, “I used to suck at bodybuilding because I could never figure out the peaking process.” But at this show, he “finally looked like a bodybuilder and people were like, ‘Wow, this is a big deal.’”
He hasn’t turned pro yet — but that’s okay
Despite his efforts, he hasn’t yet been able to turn professional as a bodybuilder — or, as they call it in the game, he’s not achieved his “pro card.” When he came second in the NPC Nationals, it was his highest finish to date, though.
Sadly, he still fell short of that pro card — but he maintains all he wants to do is compete until he achieves a certain look. After that, he claims he’ll be happy to hang up his dumbbells.
The slippery slope of steroids
In 2022 Dr. Israetel told The Washington Post that he’d first become interested in bodybuilding in high school — and when he tried it, he found he could pack on muscle quickly. Interestingly, though, he admitted to experimenting with steroids when he was 27 — and he quickly developed a taste for it.
He admitted, “I kept getting bigger, and I thought, ‘Oh, I could look even bigger.’ And then I started reading muscle magazines, and I fell in love with the idea of just becoming a freak.”
He knows bodybuilding may have shortened his life — but he’s okay with that
“I’m almost to that size,” he told The Washington Post. “These are pictures that I’ll have forever, that I can look back on and say, ‘Wow, I really did the thing. I really looked the part — like the part that I was truly capable of looking — within reason.’”
Even though he admits bodybuilding and steroids will likely have shortened his life by up to five years, he has no regrets. He insisted, “If I wanted to live until I was 90 or 100, I would absolutely have never taken steroids, or I sure as Hell would’ve quit by now.”