Ask the Experts: What is Intensity?

By Daniel Ketchell

If you’re like me, you’ve probably noticed that fitness experts throw around all of the different forms of the word “intensity” quite a bit. “Intense” might be the most frequently used adjective in fitness, but for the average person, the experts might as well be speaking Latin (in fact, the word can be traced back to the Latin tendere, “to stretch”).

It’s fantastic to read an article about how an “intense” workout can change your body’s relationship with carbohydrates, but if you don’t have a sense of intensity... you might find yourself wondering if you pushed hard enough to allow yourself some white rice.

I wanted to get to the bottom of just what they mean when they talk about intensity, so I asked all of our fitness experts to send me their thoughts so I could share them with you here. You can read them below.

Have any other questions you’d like me to ask the whole crew? Send them to me on twitter and I will try to make this a regular column where you can get answers (@ketch).


Intensity means working as hard as you possibly can. It is giving your best effort so that you walk out of the gym feeling completely satisfied because you know that you didn’t leave 1 or 2 or 10 reps in the tank.

Here’s one of my favorite moves when I think about intensity: Do 10 sets of curls with a training partner, and agree that the barbell will never touch the ground. I will do my 10 reps, then immediately pass the barbell to my partner, who will do his and pass it back to me. You can do this with almost any exercise, and because you are only able to rest while your partner works, you have to rely on each other and trust that you each will give your best effort. You both know that if you can only squeeze out 2 reps, your partner won’t be able to rest enough. When you finally finish, it will hurt so much that you won’t even know where to rest your arms, but you also know that the discomfort and pain means one thing: growth.

(If you don’t have a partner, you can simulate this with a stopwatch, and just make sure that your rest periods are the same amount of time that it takes you to complete each set. If it takes you 30 seconds to do 10 curls, don’t rest more than 30 seconds before you pick up the barbell and start the next set.)

John Romaniello

If you're speaking in strict, professional or technical terms, there's really only one definition of intensity in the weight training context: the amount of work required to achieve the activity and is proportional to the mass of the weights being lifted -- that is, how heavy the weight is relative to how strong you are. (For you muscle nerds, it's the range you are working in relative to your 1-Rep Max.)

Thankfully, speaking strictly in professional or technical terms isn't really my style; instead, I like to speak in half-truths and colloquialisms. Well, that's only partially true.

Anyway, intensity. As I see it, intensity is really just a measure of both how hard you're working and how hard you're willing to work. You can't have an intense workout if you don't have an intense mindset. Intensity means being willing to push your body just a little bit further than you want to; being willing to force your body to give a little bit more than it wants. 

An intense workout is one during which you're constantly moving, pushing as hard as you can. Not every rep on every set--but at least one set of each exercise. At least one set on every movement you perform should be all-out, balls to the wall,intensity--the goal should be to leave it on the field, as they say. 

You can do that every workout; and when you do, you'll see an exponential increase in your results.

Adam Bornstein

Intensity is not workout dependent. You can have an intense workout using barbells, dumbbells, kettlebells, bodyweight, yoga, or maybe even tantric sex. (Hypothetically speaking, of course.)

The key with all of these is mindset and focus. Intensity is dependent on your ability to zone in and push yourself without any other distractions. When you’re at work, if you multi-task too much your production suffers. If you’re at home and you’re oblivious and distracted, your relationships suffer. If you’re in the gym and you’re on the phone or your mind is on something else, then your performance will suffer. And that is what undercuts most training sessions.

Intensity is the most important variable because it determines your ability to give everything to your workout. The moment that your mind is keyed in on the main objective—working hard and getting results—that’s when you’ll discover the desired intensity needed for a great workout.

Jim Smith

Trying to define training intensity is difficult because each lifter has a different view of what intense really is. The easiest way to understand intensity of a workout or exercise is to use an individual scale.  This rating is referred to as the rate of perceived exertion or RPE.  Using a 1-10 scale, a light workout used for recovery or just to break a sweat, might be a 1-2 RPE rating.  This means a heavy squat workout where you pushed yourself for a heavy single or triple, might be an 8-9 rating.  But remember, pushing the intensity in a workout isn’t limited to just the amount of weight you lift.  Shortening the rest periods between sets, increasing the reps you do for an exercise, or performing free weight compound movements over machine exercises, are all great choices as well.  The bottom line is that if you don’t push yourself into the top end of the RPE scale often enough, you’re not training intensely and it is going to be much harder for you to continue progressing in the gym.

Alli McKee

Intensity is relative and varies based on the individual, the level of intent (from low to high) and a perceived level of that effort. Highest intensity is a degree of exertion that flirts with your physical limits and is often contingent on your mental threshold as well. High intensity efforts can show up in a variety of ways, for example (but not limited to), performing an exercise as fast as you can, as heavy as you can or for as much volume as you can.

Intensity can heighten our senses and will elicit a physical response. For me, signs of intensity sometimes include gasping for a breath after an intense effort of conditioning, getting the shakes in my hands or legs after an intense effort of strength (often deadlifts) or my mind begins to negotiate a stopping point during high volume work.

Important to remember, however, to compare my intensity to your intensity, is essentially comparing apples to oranges because I don’t feel your effort and you don’t feel my effort. 

Zach Even-Esh

The definition of "Intensity" will vary from person to person. Your level of physical AND mental fitness will determine how you view intensity. What you rate as a high intensity workout might be considered a warm up for someone else, or vice versa.

The bottom line is this: You MUST challenge yourself when training or your body will adapt to the workouts and never make progress. Does this mean you must lay on your back or crawl on your knees to get to your car after every workout? NO. That will lead to physical & mental burn out.

Workouts should challenge you, but you should almost always be able to leave the workout with some energy in the tank, allowing you to stay motivated and energized to want to come back for the next workout.

You will read every Coach here speaking about individualizing the intensity for your own level. This is the truth. Listen to your body AND your mind. On a scale of 1 to 10, 10 being the most intense grueling workout you could ever experience, the majority of the time you want to be around 7 or 8, on days that you feel more energetic, go ahead and push for a 9 or 10. The body and mind CAN be built up to these intense workouts, just be smart about it!

Jason Ferruggia

If you told me I’d never gain another ounce of muscle or get even half a percent stronger for the rest of my life I’d still be at the gym four or five days a week, busting my ass with just as much intensity as I do now.

Sure, noticeable physical changes are great, but that’s not the primary driving force behind my workouts. I train with passion and intensity because it defines me. Doing so keeps me sane, relieves my stress and readies me for any obstacles I’ll face in the outside world. Quite simply, it’s what I do and all I know. A workout or, for that matter, a life, lacking intensity is something I have no interest in.

Sean Hyson

The simplest way to understand intensity and gauge your own is to make sure you accomplish whatever your goal is for the workout. Write down what you want to do beforehand—the exercises, sets, reps, and rest periods—and visualize how you want the workout to go. Imagine how everything you’ll do will look and feel, from how your body is going to be positioned to where you’re going to stand and how the order of exercises will proceed. How hard will you push on certain exercises? What personal records, if any, do you want to beat this time?

Now all you have to do is follow through on your plan. If you were honest with yourself when you wrote it down—i.e., you planned a workout you knew you could complete with a solid effort—and you’re able to finish it as written, you can probably rest assured that you trained intensely enough to see results. Generally, a workout lacks intensity when you cut corners, quit on yourself, and do less than you know you’re capable of. The quality of today's workout will depend on your mood, focus, energy, and many other factors that are largely beyond your control, but as long as you stay on the course you set for yourself, you can reach your goals.

Neghar Fonooni

While there are certainly days when I am tempted to skip out on workouts, cut sets short or take the easy way out, most of the time my training is fueled by an intrinsic desire to be the best possible version of myself. Because of this drive, I will push through that last rep, hit the gym when I'm feeling lazy and schedule workouts while on vacation. This is intensity; the motivation to do what it takes, when it's least convenient is something that comes from within. It's work ethic, passion and extreme focus on the goal. The intensity that fuels your passion to train is integral to translating into physical means. Without this mindset, it's nearly impossible to actually perform what you might consider "intense" workouts. Getting through an intense session usually requires digging deep for the determination to push forward, and that starts with a strong mindset. 

The intensity of a workout itself can vary, depending on several factors: sleep, nutrition, hormones, recovery, programming and so on. The important thing is that the energy expended is equal to the energy available at the time. Intelligent training means knowing when to go balls to the wall, and when to take a few steps back; meaning, training sessions should have the appropriate intensity level based upon the aforementioned factors. An appropriately intense training session is one that usually leaves me equally recharged and smoked. I feel beat, but simultaneously energized, and ultimately accomplished. Personally, my most intense training sessions--both physically and mentally--are typically barbell complexes and sled training. They are tough to get through and require a lot of effort, but by the end, I'm always glad I didn't give up. 

Rob Sulaver

In its simplest terms, “high intensity” means you’re working your ass off.

With resistance training, we usually refer to high intensity as above 70% of our 1 rep max. So we’re talking near max effort sets with 12 reps and under.

With interval training, we usually refer to high intensity as somewhere above 60-80% of our VO2 max (it varies because it really depends on your fitness level.) You’re searching for the point at which your body starts to produce lactic acid faster than it can remove it. This is called your lactate threshold. Here’s the glorysauce - the accumulation of this blood lactate, while perhaps miserable, does a lot of wonderful things for your hormones. That’s a win.

In bro-speak, we usually refer to “high intensity” as working our ass off as in, “Damn Jaworski, that high intensity workout almost made me shout my groceries.”’

My personal opinion on high intensity? If you can workout harder, workout harder. Once you absolutely, positively can’t workout any harder....then you're just getting started.

John Kiefer

Intensity is streamlined intelligence. It's streamlining your workouts, through science, to make sure your time and energy are applied in ways that only get you jacked and strong, or lean and ripped. Nothing else.

This doesn't mean you have to ram out sets until you puke, or burst a bunch of blood vessels in your eyes. It means choosing lifts, weights, and rep ranges not to show off, but because they maximize your capacity to get strong and huge. Intensity is having the efficiency to take your body to productive limits, then having the intelligence to know when it's time to stop.

The Take Away

As I talked to this highly qualified gang, two things became very clear:

  1. Intensity is something that you can only define for yourself. What is intense for me would probably be a warm-up for a lot of this crew (Yes, including the women. I’m not ashamed to admit that - have you seen girlsgonestrong.com?) And that’s perfectly fine, as long as I’m pushing myself to my version of intensity.
  2. You don’t need to stray far from the Latin root (Remember that dumb joke I used at the beginning? There was a point.) to find your personal definition of intensity. When you exercise, you should be stretching - not in the toe touching, flexibility sense, but stretching just a little closer to your goal each session. Intensity means extending yourself far enough that you can feel your limits, and every so often, pushing right past them.

What's your definition of intensity? Let me know in the comment section below.