Fitness Glossary - Complete A-Z Dictionary of Bodybuilding Terms
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Fitness Glossary

Complete A-Z Dictionary of Bodybuilding & Gym Terms

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Introduction

Welcome to the most comprehensive fitness and bodybuilding glossary online. Whether you're a beginner stepping into the gym for the first time or an experienced lifter looking to brush up on terminology, this A-Z dictionary covers everything from basic exercise terms to advanced training concepts and gym slang.

Understanding fitness terminology helps you communicate effectively with trainers, follow workout programs accurately, and navigate gym culture with confidence. This glossary includes over 200+ terms covering anatomy, exercise techniques, training methods, nutrition concepts, and popular gym jargon used by bodybuilders and fitness enthusiasts worldwide.

Quick Navigation: Use the alphabet navigation above to jump to any letter, or scroll through to explore all terms. Each definition is written in plain language with practical examples to help you understand and apply the concepts in your training.

A

Abs (Abdominals)
The muscles of the midsection including the rectus abdominis (six-pack), obliques (side abs), and transverse abdominis (deep core). Responsible for trunk flexion, rotation, and spinal stabilization.
Abduction
Movement of a limb away from the midline of the body. For example, raising your arm to the side away from your body (lateral raise) or moving your leg outward (leg abduction).
Adduction
Movement of a limb toward the midline of the body. The opposite of abduction. Examples include bringing your arm down from a raised position or squeezing your legs together.
Aerobic Exercise
Cardiovascular exercise performed at low to moderate intensity for extended periods, using oxygen as the primary energy source. Examples include jogging, cycling, and swimming. Also called "cardio."
AMRAP
Acronym for "As Many Reps As Possible" or "As Many Rounds As Possible." A training method where you perform maximum repetitions of an exercise or complete as many rounds of a circuit as you can within a set time frame.
Anabolic
The metabolic process of building and synthesizing molecules, especially muscle tissue. Anabolic processes are promoted by proper training, nutrition (especially protein), and recovery. Testosterone and growth hormone are anabolic hormones.
Anterior
Anatomical term meaning "front." For example, the anterior deltoid is the front shoulder muscle, and the anterior chain refers to the front of the body (chest, abs, quads).
ATG (Ass to Grass)
Gym slang for performing a full-depth squat where your hips descend below parallel until your hamstrings touch your calves. Considered the deepest squat range of motion possible.

B

Barbell
A long metal bar (typically 7 feet for men, 6 feet for women) used for weightlifting. Weight plates are loaded on both ends. Standard Olympic barbells weigh 45 lbs (20 kg) for men and 35 lbs (15 kg) for women.
Bench Press
A fundamental compound exercise where you lie on a bench and press a barbell or dumbbells upward from chest level. Primarily targets the pectoral muscles (chest), anterior deltoids (shoulders), and triceps.
Biceps
The two-headed muscle on the front of your upper arm responsible for elbow flexion (bending) and forearm supination (rotating palm upward). Trained with curling movements.
BMR (Basal Metabolic Rate)
The number of calories your body burns at complete rest to maintain basic physiological functions like breathing, circulation, and cell production. Represents 60-75% of total daily energy expenditure.
Body Composition
The percentages of fat, muscle, bone, and water that make up your total body weight. In fitness, it typically refers to the ratio of lean body mass to body fat percentage.
Bro Split
A traditional bodybuilding training program where you train one major muscle group per workout day (e.g., Monday: Chest, Tuesday: Back, Wednesday: Legs, Thursday: Shoulders, Friday: Arms). Each muscle is trained once per week with high volume.
Bulk / Bulking
A training phase focused on gaining muscle mass by eating in a calorie surplus (consuming more calories than you burn) combined with progressive resistance training. Typically involves gaining both muscle and some fat.
Burnout Set
A high-repetition set performed at the end of a workout or exercise, typically using lighter weight, to completely fatigue the target muscle. Often done to failure.

C

Calisthenics
Bodyweight exercises that use minimal or no equipment, relying on your own body weight as resistance. Examples include push-ups, pull-ups, dips, squats, and planks.
Calorie
A unit of energy used to measure the energy content of food and the energy expenditure of physical activity. Technically, a kilocalorie (kcal) or "food calorie" equals 1,000 small calories.
Calves
The muscles on the back of the lower leg, consisting primarily of the gastrocnemius (larger, upper portion) and soleus (smaller, lower portion). Responsible for plantarflexion (pointing the toes).
Cardio
Short for cardiovascular exercise. Any activity that elevates your heart rate and improves cardiovascular fitness. Includes running, cycling, swimming, rowing, and elliptical training.
Catabolic
The metabolic process of breaking down complex molecules into simpler ones, including the breakdown of muscle tissue for energy. Occurs during intense training, inadequate nutrition, or prolonged calorie deficits.
Circuit Training
A workout method where you perform a series of exercises (typically 5-10) back-to-back with minimal rest between exercises. After completing all exercises (one circuit), you rest briefly and repeat for multiple rounds.
Clean
An Olympic weightlifting movement where you explosively lift a barbell from the floor to shoulder height in one motion. Can be performed as a power clean (caught in quarter squat) or full clean (caught in deep squat).
Compound Exercise
A multi-joint exercise that works multiple muscle groups simultaneously. Examples include squats (works quads, glutes, hamstrings), bench press (chest, shoulders, triceps), and deadlifts (entire posterior chain). Most effective for building overall strength and muscle mass.
Concentric Contraction
The lifting or "positive" phase of an exercise when the muscle shortens while generating force. For example, the upward phase of a bicep curl or the pushing phase of a bench press.
Core
The muscles of the midsection including abs, obliques, lower back, and hip flexors. The core stabilizes the spine and transfers force between the upper and lower body during movement.
Cut / Cutting
A training phase focused on losing body fat while preserving muscle mass by eating in a calorie deficit combined with resistance training and cardio. The goal is to reveal muscle definition and achieve a leaner physique.

D

Deadlift
A fundamental compound exercise where you lift a loaded barbell from the floor to hip height by extending the hips and knees. Trains the entire posterior chain: glutes, hamstrings, lower back, traps, and grip. Considered one of the "big three" powerlifting movements.
Definition
The visibility of individual muscles and their striations, achieved through low body fat percentage. A "defined" physique shows clear muscle separation and detail without excess subcutaneous fat.
Deload
A planned training week where you reduce volume (sets/reps) or intensity (weight) by 40-50% to allow recovery from accumulated fatigue. Typically done every 4-6 weeks to prevent overtraining and optimize long-term progress.
Delts (Deltoids)
The shoulder muscles consisting of three heads: anterior (front), medial/lateral (middle), and posterior (rear). Responsible for shoulder abduction, flexion, and extension.
DOMS (Delayed Onset Muscle Soreness)
Muscle pain and stiffness that peaks 24-72 hours after intense or unfamiliar exercise. Caused by microscopic damage to muscle fibers during eccentric contractions. A normal part of training adaptation, not an indicator of workout effectiveness.
Drop Set
An intensity technique where you perform a set to failure, immediately reduce the weight by 20-30%, and continue for more reps without rest. Can be repeated multiple times to completely exhaust the muscle.
Dumbbell
A short bar with weights on both ends, designed to be held in one hand. Available in fixed weights (rubber-coated, chrome, etc.) or adjustable (where you can add/remove weight plates).
Dynamic Stretching
Active movements that take joints and muscles through their full range of motion, typically performed as part of a warm-up. Examples include leg swings, arm circles, and walking lunges.

E

Eccentric Contraction
The lowering or "negative" phase of an exercise when the muscle lengthens while under tension. For example, lowering the weight during a bicep curl or descending in a squat. Eccentric training causes the most muscle damage and soreness.
EMOM (Every Minute On the Minute)
A workout format where you perform a specific number of reps at the start of every minute, rest for the remainder of that minute, then repeat. Popular in CrossFit and conditioning workouts.
Endurance
The ability to sustain physical activity over extended periods. Muscular endurance is the capacity of muscles to perform repeated contractions against resistance without fatiguing.
EPOC (Excess Post-Exercise Oxygen Consumption)
The elevated oxygen consumption and calorie burn that continues after intense exercise, commonly known as the "afterburn effect." High-intensity training creates greater EPOC than steady-state cardio.
EZ Bar
A shorter, curved barbell designed to reduce wrist strain during curling movements. The angled grips allow for a more natural hand position during bicep and tricep exercises.

F

Failure (Training to Failure)
The point during a set where you can no longer complete another repetition with proper form despite maximum effort. A training intensity technique used to maximize muscle stimulus, but shouldn't be done on every set.
Fascia
Connective tissue that surrounds and supports muscles, organs, and other structures in the body. Tight fascia can restrict movement and cause discomfort; foam rolling and stretching help maintain fascial health.
FFMI (Fat-Free Mass Index)
A measurement that estimates muscle mass relative to height, similar to BMI but accounting for body composition. Used to assess muscular development and natural genetic limits (FFMI of 25 is generally considered the natural limit for men).
Flex
To contract a muscle voluntarily, typically for posing or demonstrating muscular development. Also refers to bending a joint (opposite of extending).
Forced Reps
Repetitions performed beyond failure with assistance from a spotter who provides just enough help to complete 2-3 additional reps. An advanced intensity technique for breaking through plateaus.
Form
The technique and body mechanics used during exercise execution. Proper form maximizes muscle activation, minimizes injury risk, and ensures effective training. "Form over ego" emphasizes using correct technique rather than lifting excessively heavy weights.
Free Weights
Barbells, dumbbells, kettlebells, and weight plates that aren't attached to machines. Allow for natural movement patterns and require greater stabilization than machines.
Frequency
How often you train per week or how often you train each muscle group. Modern research suggests higher frequencies (training each muscle 2-3x per week) are optimal for hypertrophy compared to traditional once-per-week "bro splits."

G

Gains
Gym slang for progress in muscle size, strength, or overall physique development. "Making gains" means successfully building muscle or improving performance.
Giant Set
Four or more exercises performed consecutively for the same muscle group with minimal rest between exercises. An advanced training technique for maximum muscle fatigue and metabolic stress.
Glutes
The buttocks muscles consisting of gluteus maximus (largest), gluteus medius, and gluteus minimus. Responsible for hip extension, abduction, and rotation. Critical for lower body power and aesthetics.
Glycogen
The stored form of glucose (carbohydrates) in muscles and liver. Primary fuel source for high-intensity exercise. Depleted glycogen leads to fatigue and reduced performance; replenished through carbohydrate intake.
Grip Strength
The ability to hold and squeeze objects with your hands. Important for exercises like deadlifts, rows, and pull-ups. Can be trained with heavy carries, hangs, and grip-specific tools.

H

Hamstrings (Hams)
The three muscles on the back of the thigh responsible for knee flexion and hip extension. Consists of biceps femoris, semitendinosus, and semimembranosus. Trained with leg curls, Romanian deadlifts, and good mornings.
HIIT (High-Intensity Interval Training)
Cardiovascular training alternating between short bursts of maximum effort (20-60 seconds) and brief recovery periods. More time-efficient and creates greater EPOC than steady-state cardio.
Hypertrophy
The scientific term for muscle growth—an increase in muscle fiber size. Optimal hypertrophy training typically involves 8-12 reps per set, 3-5 sets per exercise, and training each muscle 2-3 times per week.

I

IIFYM (If It Fits Your Macros)
A flexible dieting approach where you can eat any foods as long as they fit within your daily macronutrient targets (protein, carbs, fats). Emphasizes hitting macro goals rather than restricting specific foods.
Intensity
In strength training, refers to the weight lifted relative to your one-rep max (e.g., 80% of 1RM is high intensity). In cardio, refers to the level of effort or heart rate during exercise.
Isometric Contraction
Muscle contraction where the muscle generates tension without changing length. Examples include holding a plank or wall sit. No joint movement occurs during isometric exercises.
Isolation Exercise
A single-joint exercise targeting one specific muscle group. Examples include bicep curls (biceps only), leg extensions (quadriceps only), and lateral raises (medial deltoids). Used to add volume to specific muscles after compound exercises.

J

Jacked
Gym slang for having significant muscle mass and definition. Someone who is "jacked" has a muscular, impressive physique with visible muscle separation.
Junk Volume
Excessive training volume that doesn't contribute to muscle growth and may impair recovery. Performing sets beyond the point of productive stimulus creates junk volume.

K

Kettlebell
A cast-iron weight shaped like a ball with a handle, used for ballistic exercises like swings, snatches, and Turkish get-ups. Excellent for developing power, grip strength, and conditioning.
Kipping
Using momentum and body swing to assist in exercises like pull-ups or muscle-ups, common in CrossFit. Allows for higher rep counts but reduces strict muscle activation compared to controlled movements.

L

Lats (Latissimus Dorsi)
The large, wing-shaped muscles on the sides of your back responsible for shoulder adduction and extension. Developed through pull-ups, pulldowns, and rowing movements. Well-developed lats create the coveted "V-taper" physique.
Lean Bulk
A muscle-building phase using a small calorie surplus (200-300 above TDEE) to maximize muscle gain while minimizing fat accumulation. Results in slower gains but better body composition than aggressive bulking.
LISS (Low-Intensity Steady State)
Cardiovascular exercise performed at a consistent, comfortable pace for extended periods (30-60+ minutes). Examples include walking, easy cycling, or light jogging. Less taxing on recovery than HIIT.
Lockout
The final portion of an exercise where joints are fully extended. For example, locking out the elbows at the top of a bench press or straightening the knees and hips at the top of a deadlift.

M

Macros (Macronutrients)
The three main nutrients required in large amounts: protein (4 cal/gram), carbohydrates (4 cal/gram), and fats (9 cal/gram). Tracking macros involves monitoring daily intake of each to meet body composition goals.
Maintenance Calories
The number of calories needed to maintain current body weight, equal to your TDEE. Eating at maintenance prevents weight gain or loss.
Max Out
Attempting to lift the maximum weight possible for one repetition (testing your 1RM). Typically done to assess strength progress or for competition. Requires proper warm-up and should be done infrequently.
Metabolic Conditioning (MetCon)
High-intensity workouts designed to improve cardiovascular capacity and burn calories through full-body, compound movements performed in circuits or intervals.
Mind-Muscle Connection
The conscious focus on feeling and contracting the target muscle during exercise execution. Improving mind-muscle connection enhances muscle activation and growth stimulus.
Muscle Memory
The phenomenon where muscles regain lost size and strength much faster after a training break than it took to initially develop them. Due to retained muscle cell nuclei from previous training.

N

Negatives
Focusing exclusively on the eccentric (lowering) phase of an exercise, typically with weights heavier than your concentric max. A spotter assists with the lifting phase. Highly effective but very taxing.
Newbie Gains
The rapid muscle growth and strength increases experienced by beginners in their first 6-12 months of training. Beginners can sometimes build muscle even in a calorie deficit due to training novelty.

O

Obliques
The muscles on the sides of your torso consisting of external and internal obliques. Responsible for trunk rotation and lateral flexion. Create the "V" lines leading to the hips when developed and lean.
One Plate
Gym slang for one 45 lb (20 kg) plate on each side of a barbell. "Two plates" = 225 lbs (100 kg) total, "three plates" = 315 lbs (140 kg), etc.
One Rep Max (1RM)
The maximum weight you can lift for one complete repetition with proper form. Used to calculate training percentages and assess strength progress. Testing 1RM requires proper warm-up and adequate rest.
Overtraining
A state where training stress exceeds recovery capacity for extended periods, leading to decreased performance, elevated fatigue, hormonal disruption, and increased injury risk. Prevented with adequate rest, nutrition, and deload weeks.

P

Peak
The process of reaching your best possible condition for a competition or photo shoot through strategic training, nutrition, deloading, carb loading, and manipulation of water and sodium.
Pecs (Pectorals)
The chest muscles consisting of pectoralis major (larger, main chest muscle) and pectoralis minor (smaller, underneath). Responsible for horizontal arm adduction. Trained with pressing and fly movements.
Periodization
The systematic planning of training into cycles with varying volume, intensity, and exercise selection to optimize adaptations and prevent plateaus. Common models include linear, undulating, and block periodization.
Plateau
A period where progress stalls despite consistent training. Weight, reps, or muscle size fail to increase for 3-4+ weeks. Overcome by manipulating training variables, adjusting nutrition, or implementing deloads.
Posterior Chain
The muscles on the back of your body including glutes, hamstrings, lower back (erectors), and traps. Critical for posture, athletic performance, and injury prevention.
PR (Personal Record)
Your best performance in a specific lift or exercise, whether it's weight lifted, reps completed, or workout time. Also called "PB" (personal best). Achieving PRs indicates training progress.
Progressive Overload
The fundamental principle of strength training: gradually increasing training stress over time by adding weight, reps, sets, or reducing rest periods. Essential for continued muscle and strength gains.
Protein Synthesis
The biological process of building new muscle proteins from amino acids. Elevated for 24-48 hours after resistance training. Requires adequate protein intake (0.7-1g per lb body weight) to maximize muscle growth.
Pump
The temporary swelling and tightness in muscles during training caused by increased blood flow and fluid accumulation. Feels satisfying but doesn't directly indicate muscle growth. Arnold Schwarzenegger famously compared it to orgasm.

Q

Quads (Quadriceps)
The four-headed muscle group on the front of the thigh responsible for knee extension. Consists of rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. Trained with squats, leg press, and leg extensions.

R

Range of Motion (ROM)
The complete movement path of a joint during exercise, from fully stretched to fully contracted position. Full ROM typically provides better muscle development than partial reps.
Recomp (Body Recomposition)
Simultaneously building muscle and losing fat by eating at maintenance calories with high protein. Works best for beginners or detrained individuals. Progress is slower than dedicated bulk/cut cycles.
Recovery
The process by which your body repairs muscle damage, replenishes energy stores, and adapts to training stress. Requires adequate sleep (7-9 hours), nutrition (especially protein), and rest days.
Rep (Repetition)
One complete movement cycle of an exercise from start position through the full range of motion and back. Multiple reps make up a set.
Rest-Pause Training
An intensity technique where you perform a set to failure, rest 10-20 seconds, then continue for more reps. Repeated 2-3 times to extend the set and maximize muscle fatigue.
Ripped
Having extremely low body fat (typically 6-10% for men, 14-18% for women) with high muscle definition. Shows muscle striations, vascularity, and clear separation between muscle groups.
RIR (Reps in Reserve)
A method of measuring training intensity based on how many more reps you could complete before failure. RIR 2 means you could do 2 more reps; RIR 0 = training to failure.
RPE (Rate of Perceived Exertion)
A subjective scale (typically 1-10) rating how hard a set feels. RPE 10 = maximum effort/failure, RPE 7 = moderate difficulty. Used to autoregulate training intensity based on daily readiness.

S

Set
A group of consecutive repetitions performed without rest. For example, "3 sets of 10 reps" means you perform 10 reps, rest, repeat two more times.
Shredded
Extremely lean with visible muscle definition, vascularity, and striations. Typically requires body fat below 8% for men, 15% for women. Often achieved for competitions or photo shoots.
Smith Machine
A barbell fixed within vertical rails that moves only up and down. Provides stability and safety for solo training but restricts natural movement patterns and reduces stabilizer muscle activation compared to free weights.
Spotter
A training partner who assists during heavy lifts to ensure safety and help complete forced reps. Crucial for exercises like bench press where you can get trapped under the bar.
Squat
A fundamental compound exercise where you lower your body by bending the hips and knees, then return to standing. Considered the king of lower body exercises, training quads, glutes, hamstrings, and core.
Static Stretching
Holding a stretch position without movement for 15-60 seconds. Best performed after workouts to improve flexibility. May temporarily reduce strength if done before training.
Strength
The maximum force a muscle can generate. Built through low-rep (1-5), high-weight training with long rest periods (3-5 minutes). Different from hypertrophy training which uses moderate reps (8-12).
Superset
Two exercises performed back-to-back with minimal rest between them. Can target the same muscle (compound set), opposing muscles (antagonist superset), or different muscle groups. Saves time and increases workout density.
Swole
Gym slang for being very muscular and large. "Getting swole" means building significant muscle mass. Unlike "ripped," being swole doesn't necessarily require low body fat.

T

TDEE (Total Daily Energy Expenditure)
The total number of calories you burn in a day, including BMR, exercise, daily activities, and food digestion (thermic effect). Used as the baseline for setting calorie targets for bulking, cutting, or maintenance.
Tempo Training
Controlling the speed of each rep phase (eccentric, pause, concentric, pause) to increase time under tension. Notated as four numbers, e.g., 3-1-1-0 means 3 seconds lowering, 1 second pause, 1 second lifting, no pause at top.
Time Under Tension (TUT)
The total duration a muscle is under load during a set. Longer TUT (40-70 seconds per set) may enhance muscle growth by increasing metabolic stress. Achieved through slower tempos or higher reps.
Traps (Trapezius)
The large, kite-shaped muscle of the upper back and neck. Upper traps elevate the shoulders (shrugs), middle traps retract the shoulder blades (rows), and lower traps depress the shoulders.
Triceps
The three-headed muscle on the back of the upper arm responsible for elbow extension. Comprises 60-70% of upper arm mass. Trained with pressing movements, dips, and tricep extensions.
Tri-Set
Three exercises performed consecutively with minimal rest between them. Similar to a superset but with three movements instead of two.

U

Unilateral Exercise
Single-limb exercises like single-leg squats, one-arm rows, or lunges. Help correct muscle imbalances, improve stability, and identify strength differences between sides.

V

Vascularity
The visibility of veins beneath the skin, especially in arms, shoulders, and abs. Achieved through low body fat, good hydration, high blood flow, and genetics. Considered a sign of conditioning in bodybuilding.
Volume
The total amount of work performed in training, calculated as sets × reps × weight. For hypertrophy, typically measured as total hard sets per muscle group per week (10-20 sets optimal for most).
V-Taper
The aesthetic ideal of wide shoulders and back narrowing to a small waist, creating a "V" shape from front or back view. Achieved by developing lats, deltoids, and upper back while keeping waist tight.

W

Warm-Up
Preparatory activities before training to increase body temperature, blood flow, and joint mobility. Includes general cardio (5-10 min) and specific warm-up sets with lighter weights before working sets.
WOD (Workout of the Day)
Term from CrossFit referring to the day's prescribed workout. Each WOD typically has a specific name and format focusing on different movement patterns and energy systems.
Working Set
Sets performed at your target training weight and intensity, not including warm-up sets. These are the sets that count toward your weekly volume targets and create the training stimulus for growth.

X

X Reps
A training technique involving partial reps at the stretch position of an exercise after reaching failure with full reps. Designed to extend sets and increase time under tension.

Y

Yoke
Gym slang for the upper back, traps, and neck region. Having a "big yoke" means having thick, well-developed upper back and trap muscles that give the appearance of a strong, powerful physique.

Z

Zone 2 Cardio
Low-intensity aerobic exercise performed at 60-70% of maximum heart rate. Improves cardiovascular base and fat oxidation without interfering with strength training recovery. Can be performed for 30-60+ minutes.

Related Resources

Now that you understand the terminology, explore these guides and calculators to apply your knowledge:

For more fitness education, visit Bodybuilding.com, Stronger By Science, and Examine.com.