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  1. Glossary

Gym Terms: A Glossary of Lifting Lingo

Gym terms and lifting lingo explained properly: RPE, RIR, AMRAP, hypertrophy, mechanical tension, time under tension, newbie gains, dirty bulk and more.

Gym terms are the shorthand lifters and programs use for effort, volume, and progress. The ones worth knowing first describe effort (RPE, RIR, AMRAP), how muscle grows (hypertrophy, mechanical tension), and slang you’ll hear in any weight room (newbie gains, dirty bulk, deload, PPL). Each has a full page below explaining what it means for your training.

What do the effort terms mean?

They describe how hard a set was. RPE rates a set from 1 to 10; RIR counts the clean reps you had left; AMRAP means as many reps as possible.

  • RPE — Rating of perceived exertion. RPE 10 means nothing was left; RPE 8 means you had two reps left.
  • RIR — Reps in reserve. If you stop a set of 10 when you could have done 12, the set was 2 RIR.
  • AMRAP — As many reps or rounds as possible; in a program, it usually means the last set.

If a program calls for a certain RPE or RIR, that target tells you how close to failure each set should end.

What do the muscle-growth terms mean?

They describe how and why muscle grows.

  • Hypertrophy — Growth of a tissue as its cells get bigger; in lifting, it means muscle growth.
  • Myofibrillar hypertrophy — Growth from adding more contractile protein strands, called myofibrils.
  • Mechanical tension — The force muscle fibers feel as they contract against resistance; the main trigger for growth.
  • Time under tension — The seconds a muscle works during a set; slowing reps down doesn’t reliably add growth.
  • Mind-muscle connection — Focusing on the target muscle; it helps most with lighter, isolation work.

Hypertrophy is the outcome and mechanical tension is the main trigger. Slower reps and more focus change how a set feels, but they don’t replace hard, progressive sets.

What does common gym slang mean?

Most slang is shorthand for a stage of training or a way of eating.

  • Newbie gains — The fast progress of the first months, mostly from your nervous system learning the lifts.
  • Dirty bulk — Eating as much as possible to gain weight fast; the extra weight is mostly fat.
  • Deload — A planned lighter week so fatigue can clear (deload week).
  • PPL — Push, pull, legs: a three-day rotation (push pull legs routine).
  • Bro split — Training one or two muscle groups per day (bro split).
  • Progressive overload — Making training gradually harder over time (progressive overload).
  • Drop set — A hard set followed immediately by more reps at a lighter weight (drop sets).
  • 1RM — One-rep max, the most you can lift once (1RM calculator).
  • DOMS — Delayed-onset muscle soreness (does soreness mean muscle growth).

Knowing the words is the first step; knowing which one describes your stall is the useful one. Find out what’s actually stalling your progress.

FAQ

What are the most common gym terms for beginners?

Reps, sets, 1RM, RPE, RIR, PPL, deload, and progressive overload cover most programs. Learn RIR first: it tells you how hard each set should be.

What does PR mean in the gym?

A personal record is the heaviest weight or most reps you’ve done on a lift. Programs such as the Texas Method build a weekly attempt at a new record into the plan.

What is the difference between RPE and RIR?

They measure the same thing from opposite ends. RIR counts reps left in the tank; RPE is 10 minus that number, so 2 RIR equals RPE 8.

Terms A–Z

ADHMNRT
AMRAP
AMRAP stands for “as many reps as possible”—or, in CrossFit-style workouts, “as many rounds as possible.” In a lifting program, it’s usually the last set of an exercise: you complete the prescribed reps, then keep going until you can’t do another clean rep.
Dirty bulk
A dirty bulk means eating as much as you can, of whatever you like, to gain weight fast, with no tracking or limits on junk food.
Hypertrophy
Hypertrophy means growth of a tissue through its cells getting bigger.
Mechanical tension
Mechanical tension is the pulling force muscle fibers experience when they contract against resistance.
Mind-muscle connection
The mind-muscle connection means deliberately focusing on the muscle you're training—feeling it stretch and contract—instead of just moving the weight.
Myofibrillar hypertrophy
Myofibrillar hypertrophy is muscle growth from adding more myofibrils—the contractile protein strands that produce force.
Newbie gains
Newbie gains are the unusually fast strength and muscle gains most people make in their first months of lifting.
RIR
RIR means reps in reserve: the number of clean reps you still had in the tank when you ended a set.
RPE
RPE stands for rating of perceived exertion.
Time under tension
Time under tension (TUT) is the total time a muscle works during a set—every second of lifting, lowering, and pausing.
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