Dr. Rhonda Patrick: Shifting a little bit into mechanics and, like, the training load, I mean, that's a big one. I mean, for the longest time, you know, I remember you'd hear lift heavy or lift big or go home or something like that. I mean, like, you know—

Dr. Brad Schoenfeld: Go heavy or go home.

Dr. Rhonda Patrick: Yeah, that's it. Like, what does the science say about that? Like, you're— this is, you know, you've really contributed to this area about do you need to train heavy to get your gains?

Dr. Brad Schoenfeld: So, this is an area that I've done pretty much a 180. So, I've changed my opinion on so many things that, you know, that I learned as an up-and-coming sports scientist and that were treated as dogma, you know, in textbooks, that my views have, in certain respects, done a 180, and nothing can be characterized more so than loading.

Dr. Brad Schoenfeld: So, I had always thought that if you're doing anything over 12 to 15 repetitions, it's basically glorified cardio and that, you know, it's just muscle endurance, you're not going to gain muscle. The literature has now shown this compellingly. There's so much literature on the topic. Our lab has done quite a bit of research, as well as many others, and it shows that you can gain muscle, similar amounts of muscle, regardless of the loading across a wide range of loading spectrums, up to 30 to even 40 repetitions, which is a long, that's a long set. And that's at the whole muscle level.

Dr. Brad Schoenfeld: Now, there may be, and I want to really emphasize, this is not— this is still equivocal, there may be some muscle type, muscle fiber type-specific benefits to doing light loads for type I fibers and type II fibers for heavy loads. If you're asking me my confidence in that literature, it's, you know, modest at best, but I can't rule out that that would be the case. But when you're looking, let's say, at MRI data or ultrasound, which we've used extensively, the results really show no difference. And I'll tell you what I think is a quite funny story, looking back.

Dr. Brad Schoenfeld: But Stu Phillips had published a study circa 2012, and he went on social media, it was Facebook at the time, and it was on untrained subjects doing leg extensions, and it showed that there was no difference in whole muscle hypertrophy between 30% of 1RM, which is, like, 30 reps, versus 80% of 1RM, which was, like, 8 reps. And I remember it as clear as day saying, Stu, come on, this is untrained subjects doing leg extensions. That's— they get jacked from doing spin cycling. That was, I think, my exact quote. And I said, I'm going to do this study in trained individuals. You're going to see, there's going to be no question the trained individuals are going to need the heavier loads to get those highest threshold motor units, the type 2 fibers, into play.

Dr. Brad Schoenfeld: And lo and behold, I carried out that study and no difference. I really ate crow. And since then, there's just been so much evidence, not only in— just across the spectrum of populations, untrained, trained, older, younger, men, women, really any and every population has been extensively studied. And it really is a beautiful thing because it provides so much flexibility and options to carry out resistance training. And it's particularly, I think, beneficial for issues like training through injuries. So, if you're training through injuries, heavy loading can be contraindicated. And also, particularly for the older individuals, because joint-related issues, as you know, as people get older, they get osteoarthritis and other joint-related issues.

Dr. Brad Schoenfeld: Heavy loading can be very uncomfortable for them and perhaps debilitating. So, it's kind of contraindicated. And they can use lighter loads. Now, the caveat to this is that the lighter loads have to be taken with a high degree of effort. So, they have to really— if you do not extensively challenge your muscles, meaning that the last few reps are difficult to complete, you're not going to achieve gains. So, when I talk about light loads, it's not about, you know, taking pink dumbbells and just, you know, doing some lifting. Okay, I stop. You must challenge the muscles. So, heavier load, when you lift heavier, just innately, you're going to challenge the muscles regardless because the weight is already heavy.

Dr. Brad Schoenfeld: With lighter loads, the first number of repetitions are very easy to complete. And if it's easy to complete, you're really not doing much to challenge the muscles. And this goes back to a survival mechanism. So, the reason that the body— I think this is important, because the reason that the body adapts to strength training is survival. The reason that the body adapts to anything is through a survival mechanism. And if you are not challenging it in a way it is not accustomed to being challenged, it has no impetus to adapt. So, the reason that you will get these adaptations in strength, and power, and hypertrophy, muscle endurance, bone density, etc., is because the muscles and bones, etc., tendons, ligaments are being challenged beyond their present capacity.

Dr. Brad Schoenfeld: And so as you get stronger, then you have to push past that and challenge them more.

Dr. Rhonda Patrick: So, the big take-home for lifting lighter, which is what I tend to do, is to get fatigued, right, when you're doing it. And so it often means more reps, which I enjoy doing. I've done both, and I do find for me I like doing the lighter lifting and more reps versus doing heavier and fewer reps. And I also notice I'm less likely to injure my wrist if I'm doing— now, maybe that wouldn't— if I was doing things like proper form and all that, maybe it wouldn't be such an issue. What about— so, you mentioned with the lifting lighter and, you know, the important thing of basically fatiguing yourself, right?

Dr. Rhonda Patrick: Like, you can't just do a couple, and it's like, you know, compare that to lifting heavier and doing a couple, right? This whole idea of training to failure, and what does that mean? Do we need to train till failure? Is that important?

Dr. Brad Schoenfeld: Yeah. So, failure, for an operational definition, would be the inability to perform another repetition with proper form. And we carried out a meta-analysis recently on this topic, and the bottom line is that the go-hard-or-go-home philosophy—that every set needs to be taken to failure—is not supported by the evidence. So, certainly, you need to train with a high amount of effort.

Dr. Brad Schoenfeld: But certainly, taking every set to failure not only shows no benefit for hypertrophy; it actually showed a small detriment for strength. Okay. So, with strength, stopping a couple reps short of failure seemed to have better effects on maximizing strength than training to failure. Again, there are some limitations to that research, how much of that— does that mean that if you train to failure you won't maximize your strength? I'm not necessarily on board with that, but that is what our results showed. I also would not dismiss the fact that, for very high-level— Let's say you're very close to your genetic ceiling, that it might make the need to go to failure, at least on some of the sets, more relevant, beneficial.

Dr. Brad Schoenfeld: We don't have good— this is purely speculative on my end, but I can see at least a logical rationale where it makes your challenge— it's a way to challenge the body in a way that it is not used to. I will tell you that when I coach bodybuilders, I generally incorporate some failure training. But another area where my view has shifted, maybe not 180, but probably 90 degrees, where I used to be the go-hard-go-home dude who every set needed to be taken to failure, and now most sets within 2 to 3 reps of failure. So, there's a concept called the repetitions in reserve, and a zero— it's the RIR scale, repetitions in reserve. Okay. An RIR of 0 means you're at failure, means you cannot have done another rep. There's 0 reps left before you go to failure.

Dr. Brad Schoenfeld: An RIR of 1 would mean that you could have done 1 more rep, and at that rep, you would be at failure. From the literature, although we don't have a definitive way of making, you know, estimates on this, but my own interpretation of the literature is somewhere between probably an RIR of 1 to 3—one to three repetitions from failure would be needed to promote optimal adaptations. You can still see adaptations, particularly when you're more in the newbie stage, in the early stages, below that. But 1 to 3, I think, is a good general recommendation that's necessary to see adaptations. Again, then you start getting into the weeds, getting into the nuances. For the gen pop, I probably would say that's always going to be effective, and you'd probably never have to go to failure for the goals of most gen pops.

Dr. Brad Schoenfeld: For bodybuilders, high-level athletes, perhaps some failure training, the last set to failure on some of your exercises, at least. And, again, you want to get into the weeds, probably using your single-joint and machine-based exercises would be more appropriate for failure, let's say, than squats, or a biceps curl, a lateral raise, a leg extension, they're going to be— first of all, there's less issue of injury because when you're going to failure, let's say, in a squat, and you're— if you've ever squatted—

Dr. Rhonda Patrick: Yeah.

Dr. Brad Schoenfeld: And you're in the hole and you're trying to push out, there's a greater potential for injury. You get— certainly you're going to need a spotter in that regard, or else you could be stuck and you can have problems.

Dr. Brad Schoenfeld: Or a bench press where you're trying to do that rep, if you don't have a spotter, that bar is stuck to your chest. Whereas if you're doing, let's say, dumbbell curls or lateral raises, at the very least, you're not going to be really torched after your sets. You're going to be able to come back strong. So, these are just general— it's speculative on my part, but I think there's good logical rationale behind these. And I do want to say that an evidence-based approach, so I do want to promote, one of the things I—look, my biggest hobbyhorse in life is to promote the importance of evidence-based practice. It is not simply deferring to research. Research is never going to tell you what to do, or virtually never.

Dr. Brad Schoenfeld: It's going to provide general guidelines, particularly in the applied sciences like exercise and nutrition. It will get you into the ballpark, you know, give you general—

Dr. Rhonda Patrick: Yeah.

Dr. Brad Schoenfeld: —strategies to use. You then need to take this to the individual. What are their genetics? What is their lifestyle, their stress level, their sleep, their nutritional status? All of these things together, and then, of course, goals are going to enter into it. So, developing a program from the research means to understand the research and then to use your own expertise in combination with the goals and abilities of the individual.

Dr. Rhonda Patrick: Right. With designing the training program sort of aspect, we're kind of, I mean, sort of talking about this.

Dr. Rhonda Patrick: And, you know, the training until failure, it sounds like that's pretty clear for me. Like, you know, maybe the bodybuilders, that's a little bit more important. But for most people, getting within 1 to 3 reps until failure. So, that kind of answers the— well, you get a lot of questions about, how many reps do I need to do? How many reps do I need to do? It sounds like it depends on the person. And when you start to feel that fatigue, when you're getting close, you know, right? Like, so that's kind of what I'm thinking for myself. Correct. Resting between those reps or between the sets, or which way is it? The resting intervals.

Dr. Brad Schoenfeld: Between sets.

Dr. Rhonda Patrick: It's between the sets. So, yeah.

Dr. Rhonda Patrick: So, basically, when you're getting ready to do another set, like, how many sets do you need to do or how long do you have to rest between them?

Dr. Brad Schoenfeld: Yeah. So, again, it's on a spectrum and it depends on— so, when I talk to my students, they'll ask me questions and I say, you know, pretty much any applied question you're going to ask me, I will answer with “it depends.” Because within broad spectrums, you can gain— if you're doing a very minimalist routine, you can make gains. So, if you're saying, is it important, it starts to become more and more important the more important it is to you to maximize your results.

Dr. Brad Schoenfeld: If your goal is just to build some muscle, gain some strength, a very minimalist routine, I mean, training an hour a week, let's say, 2 days, 2 half-hour sessions a week can give you very nice— most people, very nice results, provided you're training hard. If you're looking to be a bodybuilder or step on stage, is that going to be sufficient? No. I can say with 100% confidence, that is not going to be sufficient to optimize your gains. So, volume has been shown to be a driver of hypertrophy. Again, we've done original research on this, we've done meta-analytic work. And there is a dose-response relationship up to a certain point. It is individual-specific as well. So, some people respond better to, or respond well to lower volumes, some people need more volume to maximize their results. Hard to study individual responses, but these are kind of general insights that we glean from the literature. But I would say, as a general guideline, to optimize hypertrophy, you want to be somewhere between 10 to 20 sets per muscle per week. Now, that's not going to be able to be done doing 2 half-hour sessions per week. But we recently published a review paper called No Time to Lift. It's open access. You can maybe post on this podcast the link to that or show the image of the study. But we basically kind of looked at what is your minimal effective dose, and that was roughly around 4 sets per week, per muscle per week, which, again, can be done in two to three half-hour sessions per week. You can get very nice results. And I think get probably, for most people, the majority of gains in that period of time. And then if you want more, you're going to have to devote more time.