Strength training,
defined.
Plain-English definitions for the terms you'll hear in the gym, online, and inside Checkfit.
1RM (One-Rep Max)
The maximum weight you can lift for a single repetition of an exercise with proper form. Used as a reference point for programming percentages, though estimated 1RMs from submaximal sets are usually safer and more useful day-to-day.
Accessory Lift
A secondary exercise performed after the main compound lifts in a session. Accessories target specific muscles, address weak points, or add volume to areas the big lifts don't fully cover — think rows, curls, lateral raises, leg curls.
Accumulation Phase
A training block focused on building volume. More sets and reps at moderate intensity, designed to drive muscle growth and increase your work capacity. Usually the first phase of a mesocycle, before intensification.
AMRAP (As Many Reps As Possible)
A set performed for the maximum number of reps possible with a given weight, usually stopping at or very near failure. Often used on the final set of an exercise to test progress or push a hard stimulus.
Bodybuilding
A training style focused on maximizing muscle size, symmetry, and definition. Typically uses moderate-to-high rep ranges, controlled tempo, and a high volume of both compound and isolation work, paired with deliberate nutrition.
Cluster Set
A set broken into mini-sets separated by very short rests, usually 10-30 seconds. Lets you accumulate more reps at a heavier load than you could in a single straight set, while keeping form and bar speed intact.
Compound Lift
An exercise that moves multiple joints and trains multiple muscle groups at the same time. The squat, bench press, deadlift, overhead press, row, and pull-up are the classic examples — and the foundation of nearly every good program.
Concentric
The lifting portion of a rep, where the working muscle shortens under load. Standing up from a squat, pressing the bar off your chest, pulling the bar to your hips in a row — all concentric.
Cut
An intentional period of eating in a calorie deficit to lose body fat, usually while continuing to train to preserve muscle. Opposite of a bulk. Most lifters cycle between cuts, bulks, and maintenance over the course of a year.
Deload
A planned week of reduced training volume or intensity that allows your body to recover and adapt to the work you've done. Typically scheduled every 4-6 weeks. Without deloads, fatigue accumulates faster than progress.
Drop Set
A technique where you perform a set to or near failure, immediately drop the weight, and continue for more reps without rest. Used to extend a set past normal failure and squeeze out additional growth stimulus on isolation work.
Eccentric
The lowering portion of a rep, where the working muscle lengthens under load. Descending into a squat, lowering the bar to your chest, lowering a curl. Slower eccentrics increase time under tension and often muscle damage.
Failure (Training to)
Continuing a set until you physically cannot complete another rep with good form. Useful in moderation — usually the last set of an exercise — but very costly to recovery if used on every set of every session.
Hypertrophy
The process of muscle fibers growing larger in response to training. Built primarily through training volume, mechanical tension, and progressive overload — usually with moderate weights, moderate-to-high reps, and proximity to failure.
Intensification Phase
A training block that shifts toward heavier loads and lower reps, after an accumulation phase. The goal is to convert the size and work capacity you built in accumulation into raw strength expression.
Isolation Lift
An exercise that moves one joint and trains a single muscle group. Bicep curls, leg extensions, lateral raises, leg curls, tricep pushdowns. Less systemically fatiguing than compounds, great for targeted volume.
Linear Progression
A simple progression model where you add a small amount of weight to the bar each session. Works well for beginners — for a while — but breaks down once your recovery can't keep pace with the load increases.
MAV (Maximum Adaptive Volume)
The most weekly sets you can do for a given muscle while still making gains. Push past this and additional volume slows recovery without adding growth. Sits just below MRV in most volume frameworks.
MEV (Minimum Effective Volume)
The fewest weekly sets needed to drive any growth in a given muscle. Below this number you're only maintaining, at best. Useful floor when starting a new mesocycle or coming off a deload.
Mesocycle
A training block, typically 4-8 weeks long, organized around a specific goal — hypertrophy, strength, peaking. Mesocycles usually end with a deload week to consolidate the adaptations and clear accumulated fatigue.
MRV (Maximum Recoverable Volume)
The most weekly volume your body can recover from. Past this point, fatigue accumulates faster than you can adapt and progress stalls or reverses. Knowing your rough MRV is what makes deloads make sense.
Negative (eccentric overload)
Loading the lowering phase of a rep with weight heavier than you can lift concentrically — usually with a spotter helping you back up. Very effective for building strength and muscle, but extremely fatiguing.
Periodization
The practice of organizing training into structured phases over weeks and months to drive specific adaptations and manage fatigue. Mesocycles, accumulation and intensification phases, and deloads are all periodization tools.
Powerbuilding
A hybrid training style that combines powerlifting's heavy compound work with bodybuilding's higher-rep accessory volume. The goal is both strength on the big lifts and visible muscle development.
Powerlifting
A strength sport contested in three lifts — the squat, bench press, and deadlift — where the goal is to lift the heaviest possible weight for one rep in each. Programming centers on building maximal force production.
Progressive Overload
The principle that to keep getting stronger or bigger, you must gradually demand more from your muscles over time. More weight, more reps, or more sets — applied systematically, not randomly. The single non-negotiable rule.
Pump (Muscle)
The temporary swelling of a muscle from blood and fluid accumulation during training. Feels great and looks impressive in the mirror, but only weakly correlated with long-term muscle growth. Don't chase it as a goal.
Recovery Week
Another term for a deload week. A planned reduction in volume and intensity that lets accumulated fatigue clear so you can come back stronger in the next training block. Skipping recovery weeks is how progress stalls.
Rep
Short for repetition. One complete movement of an exercise from start to finish — for example, lowering and pressing the bar one time in a bench press. The basic unit of training volume.
RIR (Reps in Reserve)
The number of reps you could still do at the end of a set before hitting true failure. Reporting RIR after each set is the most practical in-the-gym tool for tracking real training effort and driving smart progression.
RPE (Rate of Perceived Exertion)
A 1-10 scale rating how hard a set felt. RPE 10 means no reps left in the tank. RPE 8 means two reps in reserve. Inverse of RIR — both measure effort, just from opposite ends.
Set
A group of repetitions performed consecutively without rest. "Three sets of ten" means doing ten reps, resting, doing ten more, resting, and doing ten more. Sets are the building blocks of training volume.
Superset
Two exercises performed back-to-back with no rest in between. Saves time and can intensify a session, especially when the two movements don't compete for the same muscles. Limits maximal loading on either lift.
Tempo (Lifting)
The speed at which you perform each phase of a rep, often prescribed as four numbers — eccentric, bottom pause, concentric, top pause. Slower tempos increase time under tension; faster tempos let you move more weight.
TUT (Time Under Tension)
The total seconds a muscle is loaded during a set. Often used as a rough proxy for stimulus, though raw load and proximity to failure matter more. A useful concept, easy to over-index on.
Volume (Training)
The total amount of work performed in a session or week, usually measured as hard sets per muscle per week. Volume is the single biggest driver of muscle growth, within the limits of what you can actually recover from.
Warm-up Set
A lighter set performed before working sets to prepare the joints, muscles, and nervous system for heavier loading. Doesn't count toward weekly volume. Skipping warm-ups is how injuries happen.
Working Set
A set performed at a meaningful load and effort — the sets that actually drive adaptation. Warm-ups don't count. Programming, volume targets, and progression all refer to working sets, not the ramp-up.
