Know What You're Doing
Every term your program uses, explained in plain English. Filter by category or search for a word.
Hypertrophy
Muscle growth that happens when you consistently push a muscle past what it's used to, then recover and rebuild it bigger.
Progressive Overload
Gradually adding weight, reps, or difficulty over time so your body keeps adapting instead of stalling.
Volume
The total amount of work in a session — usually sets × reps × weight — the main driver of muscle growth.
Intensity
How close a set is to your true maximum effort. Higher intensity means heavier weight or fewer reps in reserve.
Specificity
You get better at what you actually train — a marathoner and a powerlifter need very different programs.
Deload
A planned week of lighter training that lets your body recover so you can keep progressing without burning out.
Periodization
Structuring training into phases (build, peak, recover) over weeks or months instead of doing the same thing every day.
Overtraining
Training more than your body can recover from — shows up as stalled progress, poor sleep, or nagging fatigue.
RPE
Rate of Perceived Exertion — a 1–10 scale for how hard a set felt, used when exact numbers don't tell the whole story.
RIR
Reps in Reserve — how many more reps you could have done before failure. "2 RIR" means you stopped two reps short.
Rep
One complete repetition of an exercise, from start position through the movement and back.
Set
A group of consecutive reps performed without stopping, followed by a rest period.
1RM
One-rep max: the heaviest weight you can lift once with full, correct form. Most strength programs are built as a percentage of it.
AMRAP
As Many Reps (or Rounds) As Possible — a set or workout performed until you hit true failure or a time cap.
Tempo
The speed of each phase of a rep, often written as 4 numbers (e.g. 3-1-1-0) for lowering, pausing, lifting, and resetting.
Time Under Tension
How long a muscle stays under load during a set — a slower tempo increases it even at the same weight.
Failure
The point in a set where you physically cannot complete another rep with good form.
Partial Rep
A rep performed through only part of the full range of motion, often used at the end of a set to extend it past failure.
Compound Lift
An exercise that works several joints and muscles at once — squats, deadlifts, presses — as opposed to an isolation move.
Isolation Exercise
An exercise that targets one specific muscle, like a bicep curl or leg extension, with minimal help from other muscles.
Isometric
Holding a muscle under tension without moving — a wall sit or plank — instead of moving the joint through a range of motion.
Concentric
The "lifting" phase of a rep, where the muscle shortens under load — the upward part of a squat, for example.
Eccentric
The "lowering" phase of a rep, where the muscle lengthens under control — often where the most muscle damage (and growth signal) happens.
Range of Motion
How far a joint moves during an exercise, from the fully stretched to fully contracted position.
Accessory Exercise
A supporting exercise that reinforces a main lift — like split squats supporting your squat — rather than being the main event.
Spotter
A second person who stands by during a heavy lift to help if you fail a rep, especially on bench press or squat.
Superset
Two exercises performed back-to-back with no rest between them, usually to save time or increase intensity.
Drop Set
A set taken to failure, then immediately continued at a lighter weight with no rest, to push past normal failure.
Circuit
A series of exercises done one after another with little to no rest, then repeated for multiple rounds.
Split
How your training week is divided by muscle group or movement — e.g. push/pull/legs or upper/lower.
Bulking
A phase of eating in a calorie surplus to support muscle and strength gains, usually with some fat gain too.
Cutting
A phase of eating in a calorie deficit to lose fat while trying to hold on to as much muscle as possible.
Zone 2
Low-intensity cardio where you can still hold a conversation — builds aerobic base without adding much fatigue.
DOMS
Delayed Onset Muscle Soreness — the ache that shows up 24–48 hours after a workout, not during it. Normal, not damage.
Active Recovery
Light movement — walking, easy cycling, mobility work — done on a rest day to aid recovery without adding stress.
Mobility
How well a joint moves through its full range under control — different from flexibility, which is passive stretch.
Flexibility
How far a muscle can passively stretch, like in a static hold — one input to mobility, not the whole picture.
Overuse Injury
An injury that builds up gradually from repeated stress without enough recovery, rather than from a single incident.
Warm-up
Lighter movement before your working sets that raises tissue temperature and rehearses the movement pattern.
Macros
Short for macronutrients — protein, carbohydrate, and fat — the three nutrients that make up your daily calories.
TDEE
Total Daily Energy Expenditure — the total calories your body burns in a day, the baseline for bulking or cutting math.
Caloric Deficit / Surplus
Eating fewer calories than you burn (deficit, for fat loss) or more than you burn (surplus, for muscle/weight gain).
Body Recomposition
Losing fat and gaining muscle at roughly the same time — usually slower than a dedicated bulk or cut, but possible for beginners.
Protein Synthesis
The process your body uses to repair and build muscle tissue after training, using protein you've eaten as the raw material.