Glossary
Plain-English definitions of the training terms used across the knowledge base — RIR, ROM, TUT, volume, frequency and more.
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Written & reviewed by Ricardo Tapia·Last updated
- BMR
- Basal Metabolic Rate — calories your body burns at complete rest to keep you alive.
- TDEE
- Total Daily Energy Expenditure — all the calories you burn in a day, including activity. Your maintenance level.
- Maintenance calories
- The intake at which your weight stays stable — equal to your TDEE.
- Calorie deficit
- Eating fewer calories than you burn, so the body uses stored energy and you lose weight.
- Calorie surplus
- Eating more calories than you burn — needed to gain muscle and weight.
- Macros
- Macronutrients — protein, carbohydrates and fat, the three nutrients that supply calories.
- Protein
- The macronutrient that builds and repairs muscle. Lifters target ~1.6–2.2 g per kg of bodyweight.
- BMI
- Body Mass Index — weight relative to height. A population screening tool, not a body-composition measure.
- Body fat %
- The proportion of your bodyweight that is fat. Better than BMI for assessing composition.
- FFMI
- Fat-Free Mass Index — lean mass relative to height. A way to gauge muscularity independent of fat.
- Lean body mass
- Everything in your body that isn't fat — muscle, bone, organs and water.
- 1RM (one-rep max)
- The most weight you can lift for a single rep of an exercise. Estimated from submaximal sets.
- Progressive overload
- Gradually increasing the demands on a muscle (weight, reps or sets) to keep driving adaptation.
- Hypertrophy
- Muscle growth — an increase in the size of muscle fibers from training.
- RIR
- Reps in reserve — how many reps you stop short of failure. A way to gauge effort.
- Failure
- The point where you can't complete another rep with good form.
- ROM
- Range of motion — how far a joint travels during a rep. Full ROM generally builds more muscle.
- TUT
- Time under tension — how long a muscle is loaded during a set (~20–40 s).
- MET
- Metabolic equivalent — a measure of an activity's intensity used to estimate calories burned.
- Wilks / DOTS
- Scores that compare powerlifting totals across bodyweights, so lifters of different sizes can be ranked fairly.
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Educational content only. Not medical advice — consult a professional for your situation.