What All Those Confusing Fitness Terms Actually Mean

What All Those Confusing Fitness Terms Actually Mean

It isn’t easy getting fit. There’s a lot to learn: Your workout itself, whether the number of reps you do matters, and then there’s all the gym and exercise lingo you’ve never heard before. Say no more. We understand, and we’ve put together this primer to help.

Illustration by Nick Criscuolo. Additional images by sumoman.co.uk, SelmaBearsSoccer, bazzadaramblerimages, ljgoyke, Peter Mooney.

Keep in mind that fitness jargon is endless, so this list isn’t comprehensive. It is made up of many terms that you may have heard before but didn’t understand, or heard a trainer toss around.

Aerobic Exercise versus Anaerobic Exercise

Not to be confused with aerobics, a form of rhythmic exercises of the 80s neon pink leotard variety, aerobic exercise relies on your body’s use of oxygen. (As a side note, aerobics is a form of aerobic exercise.) These exercises tend to be less intense forms of running, swimming, cycling, rowing and other such activities that you can keep up for an extended period of time. Its complement is anaerobic exercise, or exercise without oxygen.

When you do short bursts of powerful exercises like lift weights or sprint for the bus, you are doing forms of anaerobic exercise. Instead of using oxygen, your body draws from specific energy reserves that are very limited, which is why you can’t maintain such intense activity for very long. Both can be trained for performance improvements.

“It burns so good when I do anaerobic exercise, but I like doing aerobic exercise when I want to take it a little easier.”

What All Those Confusing Fitness Terms Actually Mean

Absolute Strength versus Relative Strength

Imagine yourself grunting with the sheer effort of successfully putting up a personal record-breaking amount of weight in an exercise. That is your absolute strength (or at least somewhere close to it), and it does not depend on your weight or how much muscle you have. Relative strength, on the other hand, is the maximum force you can produce relative to how much you weigh and the amount of muscles you have.

This important distinction helps explain how folks with smaller frames and less muscle can outperform those with bigger muscles and/or higher body weight in certain physical feats.

“Most people are familiar with absolute strength in the gym, but relative strength is what helped that lady on American Ninja Warrior kick a lot of arse.”

Body Composition

Your body composition is your individual proportion of muscle, fat, bone, and water. This is important because this proportion has a lot to do with how your body looks. Think about it: muscle tissue takes up a lot less space than fat tissue does; bone structure can differ from person-to-person; and the amount of water you hold at any given time will all affect how you look.

You can measure body composition via a variety of different methods, including caliper pinching, dual energy X-ray absorptiometry, and hydrostatic weighing, to name a few — but note that no method is completely reliable. The alternative to measurements? Look in the mirror.

“Jennifer and Stephanie weigh the exact same, but because they have different body compositions, their body shapes are very different.”

Circuit Training

Circuit training is doing a bunch of exercises (usually between 4-10) in quick succession, based on a set time or a set amount of work (i.e. number of rounds). Once all exercises have been completed, you’ve done one circuit. The exact exercises and order are up to you to create: they can combine strength training movements with dumbbells, bodyweight exercises, agility or jump drills, and so on. The point is to keep them challenging by completing all exercises with little rest.

“Today’s circuit gave me a great full-body workout in so little time!”

Compound Exercises versus Isolation Exercises

Exercises that utilise more than one group of muscles at a time. Think of the “big” movements like bench presses, squats, deadlifts, push presses, pull-ups, and so on. These all cost more energy and effort to perform them. They often make the cornerstone of many strength programs because they help you build power and strength, and they teach your body how to correctly move as a “single unit.”

Opposite to compound exercises, isolation exercises single out a particular muscle group — say, biceps or triceps. Isolation exercises are useful for bringing attention to the muscle parts that may not be pulling their own weight in a compound movement. It’s a popular form of training, especially among bodybuilders, for those who want to focus on developing specific muscles or muscle groups further. So, in our example, a bicep curl would be an isolation exercise.

“My coach says to do the big, energy-costly compound movements in the beginning of my workout when I’m most fresh, and then move onto isolation exercises after.”


DOMS is the acronym for delayed onset muscle soreness, which is that “Ugh, I never knew I had muscles there” sort of feeling that comes days after a new workout, or a particularly challenging one. You can get it from doing anything: hiking, lifting weights, sprinting, or even carrying really heavy groceries in a funny way. Some people relish in the feeling; most have a love-hate deal with it. Either way, some soreness can be a good thing, but too much soreness — just like too much of anything — can be counterproductive, especially when it robs you of strength and the motivation to return to the gym or workout again.

“Why are you walking like that?”



What All Those Confusing Fitness Terms Actually Mean


Endurance is your capacity for keeping up with the demands from a certain level of activity — your stamina, basically. When talking about endurance, we may be referring to either muscular endurance, or how long your muscles can keep up with repeatedly applying a certain amount of force before they fatigue; or cardiovascular endurance, which is the ability of your lungs, heart, and network of blood vessels to pump oxygen into your working muscles.

In general, a high endurance is crucial for people who play sports and have to keep effort high for a long time. It’s applicable in the weight room as well — hitting a higher number of reps is a challenge to your muscular endurance.

“I can’t run more than 30 minutes at a time. My endurance isn’t quite there yet.”


In the context of fitness, with strength training specifically, failure is defined as not being able to complete a repetition because your muscles have run completely out of gas. You can grunt, yell, and stomp, but when it’s become physically impossible to move the weight an inch further you’ve trained to failure. Training to failure is controversial in the lifting world: some people are for it, while many coaches would suggest doing it sparingly, as it’s highly stressful on the body — not to mention, dangerous and makes you prone to injury.

“I failed on that last rep of the pull-up. I just didn’t have any strength left to get all the way up.”

High Intensity Interval Training (HIIT)

HIIT is the type of interval training that’s focused on increasing power and strength. All HIIT is interval training, but not all interval training is HIIT. The key is that you must focus on putting out 100% effort for a short duration, resting, and then repeating this process a couple times over.

We’ve pointed out the two areas where people tend to go wrong in HIIT. Just remember that HIIT isn’t a workout to be over-emphasised for people starting out. It can be overkill and make people prone to injury if not careful.

“I’m doing HIIT at the track today instead of training in the gym. Hope I don’t puke.”


Intensity refers to how hard both your body and mind have to work when doing a physical activity. Intensity often is what makes a workout productive, but it’s relative and is self-monitored. In weight training, it is usually measured by a percentage of your one-rep max, or the highest amount of weight you can safely lift. In general, a workout that’s considered high intensity will leave you feeling gassed but in the best possible way.

Still, there’s a place for periods of low intensity as well (e.g. jogs, lighter weights, relaxing walks). You can increase intensity by reducing rest time, using heavier weight, increasing tempo, adding more sets and reps, or a combination of all of these.

“If you want to really challenge yourself in your workout, keep the intensity high!”

What All Those Confusing Fitness Terms Actually Mean


The shorthand for food macronutrients: protein, fat, and carbohydrates, which are the building blocks of every diet. Many with specific performance or aesthetic fitness goals prefer counting proportions of macronutrients (called “counting macros”) rather than kilojoules alone. It’s exactly as it sounds. You count the number of grams of carbohydrates, protein and fat to meet your goals.

Since carbs and protein are four-ish calories per gram and fat is nine-ish calories, hitting macro targets usually end up helping you get very close to calorie goals as well. Bear in mind, however, that whichever practice you prefer, it’s impossible to be 100 per cent accurate.

“With the macros on this giant muffin, I could have a similar but complete meal instead and be way more satisfied.”


You know a plateau when you see it. It’s that moment when things have flatlined: you’re not making any strength or endurance improvements in the gym; the scale doesn’t move in the direction you want it to; or your running time hasn’t gotten any better — all despite weeks of “doing everything right”. Plateaus happen to anyone and everyone, generally many weeks or months into doing the same regimen.

We’ve written a few articles here, here, and here on their causes and what you could do about them.

“In order to get past the plateau, I changed up my program a bit by adding more reps and then more weight.

Progressive Overload

Progressive overload is the principle of continually making yourself adapt to new exercise stressors and gaining strength, endurance, and muscle. (That’s a good thing!) In simpler terms, progressive overload is happening when you are doing more over time. The “more” is up to you to define: it can be more weight, more reps, more volume, more productive sessions and so on.

It sounds simple in concept, but is a bit more complicated because everyone is going to progress differently and at different speeds. There is no exact “blueprint” for anyone, but Bret Contreras outlines 10 rules to keep in mind.

“Without progressive overload, you may not be getting the results you want in strength, muscle, or fitness ability.”


Rest typically refers to the time when you’re not exerting any effort during a workout; in other words, you’re actually resting from your previous bout of effort. This allows your body’s energy systems to recover to prepare you for the next round of exercise effort. Of course, rest within a workout can be prolonged or reduced, depending on the goal.

When referring to rest outside of a single workout session, it’s the actual recovery and rest between workout sessions, which are typically a day or two (or more, if it’s a break). On the other hand, you can “actively rest” which is doing something really easy to still encourage recovery but use the opportunity to fine-tune form, technique, practice, and so on.

“When the rest periods are short, I really feel like the workout is, like, 10.7 times harder than with longer breaks.”

What All Those Confusing Fitness Terms Actually Mean


Asking for a spot is the equivalent of asking someone to catch you when you fall; to be your warm security blanket as you attempt to hoist an unfamiliar amount of weight (most commonly with the bench press or squat). A spot is often seen as a common courtesy in weight room culture.

We’ve mentioned before that most people in the gym wouldn’t make a good “spot” due to inexperience or the fact that they may have a previous injury that can be accidentally exacerbated. On the flipside, your duty as a spotter is not to help the lifter lift the weight, but to be there in case the lifter really needs you to bail him out.

“I’m about to put up three plates on this bench press and could use a spot. Could you spot me, bro?”


Supersets is a term used in strength training. You may already know that a set is completing a full cycle of one exercise’s number of reps. A superset then is completing a full cycle of two exercises’ number of reps. That means you do two exercises back-to-back before you finally pause to rest and finish one superset.

The exercise combo tends to hit opposing muscle groups, but they don’t have to. An example of a superset is a push-up followed by seated rows (targeting chest and back muscles, respectively). Supersets are helpful for adding volume, intensity, and/or quickness to a workout.

“By the end of this push-up and pull-up superset, I can barely feel my arms.”


In running, tempo is basically a faster run with some structure. You could simply do a fast run from start to finish after a little warm-up; or do intervals of higher tempo runs, such as running at a “race pace” for 5 minutes and then slow it down for 3 minutes. In the weight room, tempo is how fast or slow you perform an exercise rep.

Typically, you lift the positive, or concentric portion, as fast as possible while slowing down for the negative, or eccentric phase. There’s really a number of different ways to manipulate tempo for both lifting and running.

That tempo run was the perfect way to break up my usual long weekend run!”

What All Those Confusing Fitness Terms Actually Mean


Volume is generally used with weight training (although it can also apply to other types of training, such as number of miles ran) and refers to the overall amount of “work” in a program, in a single workout, over a week of workouts, or whatever. It’s measured a number of different ways (one example: number of sets x number of reps x weight lifted).

For our purposes here, it’s enough to know that high volume is typically more work, and volume can affect training results.

“Most beginner strength training programs are low in volume to make sure folks are recovering properly at the start.”

Workout Splits

Many beginner programs typically prescribe three workout days that target the entire body, or full-body workouts. Splits (or body part splits), on the other hand, describe how people break up their workout program to hit different body parts, or movements, within a week. For example, a 3-day split means you may be working your legs one day, chest and back muscles another day, and arms the third day.

Alternatively, people can split their routine to include all push exercises, or all pull exercises. There are many ways to create a workout split — it’s all dependent on your own goals, preferences, and schedule!

“Yo, my new workout split is really killer. I’m dreading leg day.”

Fitness jargon can feel like learning a whole other language, but once you get used to it it’s easy to forget that not everyone understands what you mean when you say that you need a spot in case you hit failure from a case of the DOMS but still need to try to smash your plateau. That’s OK. Just refer them to this decoder.

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