Gym Terms Glossary
Plain-language definitions for the training and nutrition terms you run into most often, whether you're brand new to lifting or just want a quick refresher. Each term links to the GetFitArchitect tool or article that puts it to use.
Training and programming
1RM (One-Rep Max)
The most weight you can lift for a single full rep of an exercise with good form. Used as a reference point for setting training weights at a given percentage of your max.
Estimate your 1RM →RPE (Rate of Perceived Exertion)
A 1-10 scale for how hard a set felt, where 10 means you couldn't have done another rep. Used to self-assess intensity when you're training without a spotter or a fixed percentage-based program.
How to self-assess intensity →RIR (Reps in Reserve)
How many more reps you could have done before failure. "2 RIR" means you stopped a set with 2 reps left in the tank. It's the inverse framing of RPE, and the two are often used together.
How to self-assess intensity →AMRAP (As Many Reps As Possible)
A set performed to the maximum number of reps possible with good form, rather than to a fixed number. Common on a final set of an exercise to gauge current strength or push volume.
Progressive overload
Gradually increasing the demands placed on your muscles over time, most often through more weight, more reps, or more sets, so your body keeps adapting instead of plateauing.
Read the full explanation →Volume
The total amount of work done for a muscle group, usually measured in sets per week. More volume generally drives more growth up to a point, after which recovery becomes the limiting factor.
Find your weekly volume range →Hypertrophy
Muscle growth. Training "for hypertrophy" typically means moderate reps (roughly 8-12), moderate rest, and enough total volume to drive muscle size increases, as distinct from training purely for strength or endurance.
How much volume hypertrophy needs →Superset
Two exercises performed back to back with no rest in between, then resting once both are done. Used to save time or to pair opposing muscle groups so one rests while the other works.
Deload
A planned week of reduced training volume or intensity, used to let your body recover from accumulated fatigue before it turns into a real performance decline or injury risk.
Working set
A set performed at your actual training weight, meant to count toward your workout's volume, as opposed to a warm-up set used only to prepare your joints and muscles.
Plan your warm-up sets →Compound exercise
An exercise that moves more than one joint at once, like a squat, deadlift, or bench press. Compound lifts typically let you move the most total weight and are the foundation of most programs.
Browse the exercise database →Isolation exercise
An exercise that moves a single joint and targets one muscle group directly, like a bicep curl or leg extension. Used as accessory work alongside compound lifts, not usually as a program's main driver.
Browse the exercise database →Concentric
The part of a lift where the muscle shortens under load, like the upward phase of a squat. Often called the "lifting" portion of a rep.
Eccentric
The part of a lift where the muscle lengthens under load, like the downward phase of a squat. Controlling this portion, rather than dropping into it, is a common form cue for both safety and muscle growth.
DOMS (Delayed Onset Muscle Soreness)
The muscle soreness that shows up 24-48 hours after a workout, especially after new exercises or a jump in volume. Normal and temporary, unlike the sharper, more immediate pain of an actual injury.
Tell soreness from injury →Training splits
Split
How your training days are divided by muscle group or movement pattern across the week, for example full body, upper/lower, or push/pull/legs. The right split depends mostly on how many days you can actually train.
Find your split →Full body split
A split where every session trains your whole body, typically used at 2-3 training days per week. Missing a session only reduces your weekly session count, it doesn't skip any specific muscle group.
Full body vs. PPL →Upper/lower split
A split that alternates between upper-body and lower-body sessions, typically run across 4 days. A middle ground between full body's frequency and push/pull/legs' higher per-session volume.
PPL vs. upper/lower →PPL (Push/Pull/Legs)
A split that divides training by movement pattern instead of body region: push (chest, shoulders, triceps), pull (back, biceps), and legs, typically run across 5-6 days.
PPL vs. upper/lower →Bro split
A split that dedicates each session to a single muscle group (chest day, back day, leg day, and so on), trading lower per-muscle frequency for higher volume and exercise variety in each session.
Nutrition and body composition
TDEE (Total Daily Energy Expenditure)
The total number of calories your body burns in a day, including your basal metabolic rate plus activity and exercise. Eating at your TDEE keeps your weight roughly stable.
Calculate your TDEE →BMR (Basal Metabolic Rate)
The calories your body burns at complete rest just to keep you alive, before any activity is factored in. It's the starting point TDEE is built from.
Calculate your TDEE →Calorie deficit
Eating fewer calories than your TDEE, which drives weight loss over time. Usually expressed as a percentage of bodyweight per week to keep the pace scaled to your size.
Set your deficit or surplus →Calorie surplus
Eating more calories than your TDEE, which supports weight and muscle gain over time, at the cost of some fat gain alongside it.
Set your deficit or surplus →Macros (Macronutrients)
Protein, carbohydrates, and fat, the three nutrient categories that make up your total calorie intake. Hitting a protein target matters most for muscle building; total calories still matter most for weight change.
Calculate your macros →Body fat percentage
The proportion of your total bodyweight that's fat mass, as opposed to muscle, bone, and water. A more complete picture of body composition than bodyweight alone.
Estimate your body fat percentage →