Intensity is a hot topic in the iron world. The mainstream muscle magazines seem to interpret training intensity as simply "working really hard," and will describe Mr. Sponsored Bodybuilder Du Jour's rigorous training as something like "mind-blowingly intense," further illustrated by pages of grainy photos of a 300-pound behemoth scowling through every biceps exercise the Weider brothers ever came up with.
However, after graduating beyond typical musclehead bathroom reading, one learns that "intensity" in strength training doesn't refer to the amount of emotional arousal or discomfort experienced during training, but rather the weight on the bar.
Absolute intensity refers to the absolute load on the bar, often measured in pounds or kilograms. But when people start talking about percentages in strength training, what they're referring to is relative intensity. This is a description of intensity relative to your 1-rep max.
Percentages are an integral part of intelligent strength training. They allow coaches from all corners to get on the same page, so discussions about training and loading parameters can take place without the need to ask a lot of background questions.
Yet to the new trainee, this may seem unnecessarily exclusive or pretentious, like the strength training equivalent of chubby, bespectacled men in Bazinga t-shirts greeting one another in Klingon, but understanding percentages is decidedly more useful.
Intensity – The Most Important Parameter?
For most strength sports, intensity is the parameter that determines much of the training effect. If your goal is to develop absolute strength, then that will require certain levels of intensity, just as if your goal is to develop hypertrophy, it wouldn't make sense to train with very light weights or the newest late-night infomercial gadget.
The weight on the bar – or more accurately, the effort required to move it – will determine the vast majority of your training effect. Volume will determine the magnitude of that effect.
So if you're training with a purpose in mind – any purpose – and aren't paying attention to intensity, then there's a strong chance that you won't achieve the effect you desire. Better still, the more you understand the training effect that each type of intensity can produce, the more surgical you can be in your training. And precise training is effective training.
As noted, training intensity is often described as the percentage of 1-rep max for a particular lift. But there are issues with this method, namely that the body doesn't know or particularly care about how much weight is on the bar. The adaptations that occur from training are a result of tension and duration.
The body responds to things like the force of the muscle's contraction, how long the contraction lasts, and how many contractions there were. A percentage isn't necessarily a precise way to describe this as different lifters will perform differently.
If two lifters perform 3 reps with 85%, one lifter may find the task to be moderate effort while the other may find it to be next to impossible. The ratio of fast-twitch to slow-twitch fibers, training history, and other physiological issues all play a role here.
Next, there is the matter of having accurate maxes to work with. Such accurate data isn't always available, especially for assistance lifts.
For these reasons, I prefer to describe intensities in terms of reps-per-set> and the RPE (rate of perceived exertion). This allows for greater individualization of training.
The RPE scale is described in the following chart:
@10: Maximal Effort. No reps left in the tank.
@9: Heavy Effort. Could have done one more rep.
@8: Could have done two or three more reps.
@7: Bar speed is "snappy" if maximal force is applied.
@6: Bar speed is "snappy" with moderate effort.
With this chart, not only can we describe the intensity of a lift with more accuracy, but RPE charts are also auto-regulatory in nature, meaning that they help us to modulate our training on a given day.
Here's an example. For most, doing 85% for 3 reps will result in a @9 RPE. That means when you put the bar down, you think, "Yeah, I could have done one more."
But if you forgot to pack your lunch or stayed up late watching Missing in Action (again) the night before, while you might feel half-bagged, that 85% load doesn't change – it will require the same work as it would if you were having a good day.
At a minimum, you won't get the same training effects in terms of tension and duration. Worse, you could end up injured.
A better approach is to work with RPE's so that on a bad day, the weight on the bar is reduced, since it will take less weight to reach x 3 @9. But on a good day it will take more weight to reach x3 @9. That's how RPE's are auto-regulatory in nature.
Describing intensity in terms of reps and RPE brings us closer to approximating the tension and duration that your muscles respond to, allowing for a more precise training effect.
Now that you understand the importance of properly describing intensity, here are a few potential training effects and how to achieve them.
Training for improved neural efficiency is often mistaken for training to improve maximal strength. However, a wide range of intensities can be used to improve maximal strength, not just low reps.
The goal of neural efficiency training is improving the central nervous system's ability to activate motor units through inter-muscular coordination, intra-muscular coordination, and rate-coding. To achieve these effects to help prepare for a 1RM, you need to train at high intensities.
This means you should focus your attention on the 1-3 rep range and use RPE's from 9 to 10. Something like x1 @8 could also fit into the neural efficiency category, but not as well as some others. The same applies for x4 @10, but this is bordering on other objectives.
Learning to Grind
Learning to grind is a big topic. There are very good reasons for learning how to grind out a heavy weight, although they're beyond the scope of this article. Suffice it to say, if you're unable to grind out a PR, you would've hit that PR if you could grind it out. So getting better at what you suck at is usually a priority.
To get better at grinding out a weight, basically you need to practice. That means increase the reps and RPE's slightly. Reps should sit around 3 to 6, usually concentrating on sets of around 5. RPE's will be in the @9 to @10 range, most often being @10.
Learning to be More Explosive
If you're very good at grinding out a maximum weight, then it may be time to introduce some explosiveness into your training. This will help your overall force production and can help spark new gains in maximal strength.
Developing explosiveness is basically the opposite of learning to grind. For this, you'll want to reduce the reps and RPE's. Doing 1 to 3 reps is again most effective, but keep the RPE's in the @7 and @8 range. This will allow you to do more sets to achieve the required volume levels, resulting in more "first reps." Since your first rep is your most explosive rep, this will teach your body to be more explosive.
"Hypertrophy" itself can be developed using almost any rep range, but I've found it more effective to break hypertrophy into specific parts. Addressing it this way narrows down the choices and allows more precision in our selection.
Myofibrils are the contractile elements of the muscle fiber, meaning they do the actual contracting. By growing the myofibrils larger, you'll have more contractile proteins available. More contractile proteins (used by a well-tuned nervous system) results in greater strength. Or if you're not into strength, it will result in the denser look coveted by bodybuilders.
Myofibril hypertrophy is best achieved by lower reps (by bodybuilding standards), but not "powerlifting low reps." We're talking 4 to 8 reps, with most of your time concentrated in the 5 to 6 range. This provides sufficient time under tension to stress the myofibrils into adaptation.
As for your RPE's, keep those in the @8 to @10 range. Using @8 is acceptable for the lower end of your rep range while using @10 is better if you'll be on the higher end of the rep range. If you're in doubt just use @9.
So how can you incorporate these ideas into your training?
Start by logging your RPE in your training log. This is a great habit to get into and is a much more descriptive means of describing how hard a particular set was as opposed to saying "easy" or "so-so" or "I just shit my pants."
As you learn what RPE's your program is trying to produce, start relying on them more.
For example, if your program requires you to do 3 reps with 85% and you know that this usually produces an @9 set, then just work up to 3 reps @9 and let the weight fall where it will, either above 85% if you're having a good day, or below 85% if you're having a bad day.
Eventually you'll be able to structure your program around reps and RPE's, but this takes time so let it happen organically.
Watch your RPE's long enough and you'll see the patterns show up. Then, you can start managing them and be more specific with the training effects you're pursuing. This will lead to better gains in the future.
So, to review:
- Start recording your RPE's today based on the chart above.
- As you get used to them, focus on RPE in your training rather than percentage.
- Once you notice patterns, incorporate RPE's when planning workouts.
Cautions and Caveats
Hopefully this article gave you some insights on how to use rep and RPE pairings to efficiently program your training based on a few common training objectives.
Remember, intensity is a sliding scale. We like to compartmentalize things since it helps us understand it easier, but the training effects described above aren't isolated. Training for one objective will have a certain amount of bleed over to other objectives.
Use this information to help you program your own training with greater precision, but don't forget to consider volumes as well. There are plenty of resources available to help you plan appropriate training volumes such as Preliphin's chart or a host of other tools. You can also use the RTS methods for volume management found on the Reactive Training Systems website.
Either way, greater precision in your training will result in you getting the training effect you're after. It will allow you to plan with more accuracy, and will help you get better, faster results by listening to your body – because even the best of us occasionally has on off-day!