Designing a strength training program – specifically, choosing what weight to put on the bar – is a lot like a recipe for fancy meal. You have a laundry list of ingredients that must be combined in the right amounts at the right time. If you cook them correctly, you’ll get a delicious dish. If you omit ingredients, skip steps in the recipe or overcook the dish, you’ll end up with something inedible.
But the beauty of cooking is that you have some room for error. Even if you freestyle a bit with ingredients, seasonings and cooking temperatures, your dish will likely still taste good if you adhere to the basic principles of cooking. Just like you can’t say for sure how a dish will turn out before making it, you can’t predict EXACTLY how a training program will affect a lifter. The same combination of exercises, sets, reps and load over the course of several weeks won’t yield the same results for all lifters, nor will it affect the same lifter the same way if they run that program multiple times.
Writing programs isn’t an exact science. We can debate about which exercises lead to the best strength gains and which sets-and-reps protocol sparks the most muscle growth, but ultimately, the weight on the bar matters. We’re talking about getting stronger, after all.
There are three primary methods for determining the weight on the bar:
- Percentage of 1-rep max (1RM)
- Rate of Perceived Exertion (RPE)
- Reps in Reserve (RIR)
I’ll compare and contrast these methods over the course of this series to help make sense of how and when to use each of them to get as strong as humanly possible.
Percentage of 1RM
Percentage-based training is perhaps the most talked-about and studied method for selecting training load. When you hear the word “intensity” it’s typically referring to the percentage of a 1RM. For example, if someone’s max squat was 500 lbs and their program said to do sets of 5 at 80%, they’d put 400 lbs on the bar.
Because of the mountains of research on percentage-based training, there’s plenty of evidence that it works. We can also predict with a fair amount of accuracy things like:
- How many reps someone should be able to do at a given percentage
- How much volume (sets x reps) is a reasonable amount of work at a given percentage
While the number of reps a lifter can perform at a given amount of their 1RM will vary, research and experience combined can give us a reliable range based on percentage. This chart is fairly helpful for understanding what rep range corresponds to percentage of 1RM:
However, percentage-based training is not without its drawbacks. First and foremost, percentages are only as useful as the accuracy and timeliness of the max from which you calculate your percentages. The more recent the 1RM, the more accurate your percentages. The older your max, the more likely your percentages will be off. You can’t march into the gym and yell “I benched 315 in high school!” and, neglecting to tell anyone that was 20 years ago, expect to be able to work off of 315 as your max.
Also, basing your percentages off a max performed in competition is often problematic. PRs set at powerlifting meets are often done in a state of high arousal, and I’m not talking about a Tinder date. You’re amped up more than normal, excited and anxious to get on the platform and compete. You may be highly caffeinated, feeding on the energy of the crowd and loud music, maybe even sniffing some smelling salts to channel your inner psychopath. All these things elevate your performance above what you could normally accomplish, especially during a normal training session at the gym.
You can’t use a max where you utilized every advantage in the book and expect to succeed during normal workouts. A simple solution to this issue, made popular by Jim Wendler in his 5/3/1 book: take your competition max, knock 10 percent off it and use THAT as your training max. That may sound too light at first, but you’ll thank me (and Jim) when you don’t get stapled to the floor by the bar.
In a perfect world, percentage-based training would work for everyone because your 1RM would stay consistent all the time. But in the real world, your 1RM can swing as far as 5-10 percent in either direction depending on fatigue, mental and emotional state, and outside stressors. That’s a huge range, especially if you’re pretty strong.
Imagine this: your best-ever squat is 500 lbs, but you’re having a shitty day and your 1RM on that day is down 10 percent. That’s a 50-lb decrease. So if you were trying to do sets of 5 at what you think is 80 percent (400 lbs and about a 7-rep max) but is suddenly 89 percent (about a 3-4 rep max), guess what? You’re about to get a Stone Cold Stunner from that bar.
Percentage-based training CAN work, especially if you’re the kind of lifter who needs the accountability of knowing exactly what weight you’re going to lift today. If you’re the kind of lifter who always sandbags your training and goes lighter than you could OR you’re always overshooting your weights and pushing too heavy, percentages can help keep you focused and eliminate any guesswork. But that rigidity is exactly what percentage-based training may NOT be the best option for many lifters, which we’ll discuss next.
Rate of Perceived Exertion (RPE)
RPE is a subjective rating of the difficulty of an exercise. Many scales have been developed over time for different types of exercise, but for strength training, a scale of 1-10 (with 10 being most difficult) is the most common. RPE can be used both to evaluate a set after completion (i.e., “That set was pretty tough, I’d call it a 9 RPE”) and to choose the weight on the bar for a given set (i.e., “I’m supposed to do a triple at 8 RPE, I think I can use 225 for that.”).
As you can see, there’s a bit of guess work involved with RPE. There’s less precision than the ever-objective percentage. Or is there?
RPE-based training lends itself to autoregulation, which is the adjusting of a lifter’s training based on their current level of fitness, fatigue and performance. Think of autoregulation like driving a car. It’d be great to always be able to drive at full speed down a straight highway, but life’s not always like that. Sometimes there’s rough terrain and you have to slow down. Sometimes there’s a curve and you need to turn the steering wheel. And sometimes there’s construction and you have to take a detour.
Percentage-based training works best on the aforementioned open highway. If you’re driving through the midwest on a full tank of gas with no traffic in sight, punch the gas and go for it. But what happens when you’re tired, stressed out or injured – life’s equivalent of traffic, construction and road closures? You can’t just drive right through it without slowing down and changing course.
Remember the squat scenario mentioned earlier? The lifter who’s experiencing a 10 percent decrease in 1RM because of fatigue needs to adjust their training plan that day. Rather than going for sets of 5 at 80 percent (a weight they’re just not ready for on that given day), they could instead do sets of 5 at a 7 or 8 RPE – a moderately challenging weight dictated by how they’re feeling that day. Is it perfect? No, but that training session will be far more productive than going too heavy for their current state of readiness.
Now you might think that RPE training is too hippy-dippy touchy-feely. I came here to lift weights, not sing Kumbaya around a campfire. But hold on – it’s possible to use RPE AND be objective. A popular form of RPE-based training involves used the Reps in Reserve (RIR) method and assigning an RPE rating based on how many reps were left “in the tank” at the end of the set. Basically, you perform a set and when you’re finished, you determine how many more reps you COULD have done if you’d pushed it to the max. That number subtracted from 10 is your RPE. This chart from Reactive Training Systems helps visualize the RIR method of RPE:
For example, let’s say you deadlifted 405 for a set of 6 reps. It was tough, but you know you could have ground out 2 more reps if you had to. You do the math (10 minus 2) and you have an RPE of 8.
Now, the RIR method doesn’t always work for RPE. In fact, the heavier you’re lifting (i.e., lower rep ranges) and the stronger you get over the time, the less accurate RIR becomes for judging RPE. For example, let’s say an advanced lifter can squat 800 lbs. The chart in the first section claims he should be able to squat 95 percent (760 lbs) for 2 reps. However, most high-level lifters will tell you that might not be possible. This lifter might be able to hit 760 for an easy single, but not necessarily a double. So as reps get lower (heavy sets of 1-3 reps), RPE ratings may have to be based on how difficult they felt and how much more weight you could have done, rather than the number of reps in the tank. This may differ based on the exercise as well. For example, some lifters might be able to rep out heavy weights on bench press but not on the squat or deadlift, or vice versa.
It takes a bit of practice to correctly guess the weight on the bar for RPE-based training, but with time, you’ll get good at it. This is learning to “listen to your body” like all the grouchy old lifters told me to do when you asked them for advice on all the powerlifting message boards back in the day.
What’s more, RPE can be combined with percentage-based training for maximum effectiveness. I’ll get into the practical application of this in the next article, but remember how I said we can predict how many reps most people can do at a given percentage? Well, we can also predict a person’s 1RM based on how many reps they did at a given weight and the RPE score they gave themselves.
This chart, developed by Mike Tuchscherer of Reactive Training Systems, equates RPEs at each rep range to a percentage of 1RM.
Mike himself will tell you that you must work to develop this chart for yourself, and that it’s not exact for every lifter. However, it’s a great starting point and I highly recommend you read the source article to better understand how RPE and percentages can be intertwined.
Perhaps the greatest use of this chart is to predict changes in your 1RM over time when using RPE-based training. For example, if one week you bench pressed 315 for 5 at 8 RPE, your predicted 1RM according to this chart is 388 (315 divided by .811). If the following week you do 325 for 5 at 7 RPE, your predicted 1RM jumps up to 408 (325 divided by .799). Tracking this predicted 1RM each week can help you know if your training plan is working or not. Like I said, it helps you steer the car.
Reps in Reserve (RIR)
We already mentioned RIR as a measure of how many reps were left in the tank at the end of a set. Combined with RPE, this is a powerful tool for measuring the difficulty of a set. However, RIR’s greatest utility is for hypertrophy.
There are many methods for improving maximal strength. Some involve lifting heavy weights for low volume, some involve lifting lighter weights for higher volume, and some methods combine the two. However, when it comes to building muscle, the exact weight on the bar isn’t as important as your proximity to failure (your RIR) and gradually adding volume over time.
Therefore, the role of RIR in selecting the weight on the bar boils down to a simple question: what weight will allow you to perform a number of reps in a hypertrophy rep range (about 8-20 reps)? And regardless of the weight, your aim should still be to do as many reps as possible, stopping a certain number of reps shy of failure based on your RIR assignment. Typical RIR assignments range from 0-3 RIR, because taking a muscle close to failure is necessary for growth unless you’re a completely beginner.
Let’s use dumbbell curls as an example – because we all want big arms. Rather than arbitrarily doing 3 sets of 10 reps at a certain weight, ask yourself, “What weight could I use and get at least 8 reps – but not more than 20 reps – if I stop 2 reps shy of failure?” You take a guess and choose 30 pounds, and then perform as many reps as possible, stopping when you have 2 reps in the tank (2 RIR). The exact weight and exact number of reps don’t matter, as long as you’re staying true to the RIR and going fairly close to failure.
This approach probably won’t lead to great results if applied to your squat, bench press and deadlift while chasing maximal strength. Taking these big lifts close to failure all the time isn’t sustainable, nor is it necessary to get stronger. But when applied to accessory exercises meant to add muscle, RIR is likely superior to RPE because marrying yourself to a predetermined number of reps per set isn’t the goal.
But Really, How Do I Choose the Weight on the Bar?
To summarize:
- Percentage-based training works well if the max is accurate and lifter is consistently ready to train, but lacks adaptability to day-to-day fluctuations in performance.
- RPE-based training allows for autoregulation and individualization, but takes time and practice to maximize its effectiveness.
- RIR works best for hypertrophy and accessory exercises, but isn’t terribly useful for heavy strength training on the main lifts.
In part 2, I’ll discuss how to fit percentages, RPE and RIR into a training program to get the best of all worlds.
