Gym Term Glossary

  • 11 min read

Gym Term Glossary



Gym Term Glossary

If you’re new to the gym or fitness world, you might be intimidated by all the terms and jargon used online and in your gym.

Here’s a go-to cheat sheet for some of the most common gym terms and slang.


  • Pecs: Short for pectoral muscles (chest).
  • Lats: Short for latissimus dorsi (back).
  • Traps: Short for trapezius muscles, which span across the neck, shoulders and upper back. It’s the muscles you typically think of when you ask someone to rub your shoulders.
  • Delts: Shoulders. You can work the front, middle and rear delts.
  • Tris: Triceps (the back part of the upper arm). This is the part women hate to giggle when they wave.
  • Bis: Biceps (the front part of the upper arm). People often use language like, “bis and tris” for short, when talking about the body parts they trained.
  • Quads: Quadriceps (front of the thighs).
  • Hams: Hamstrings (back of the thighs). Also playfully called Hammies.
  • Glutes: Short for gluteus maximus – a much nicer way to say “butt”.
  • Core: Refers to your trunk – your low back, mid-back, abdominals, obliques, and stabilizers.
  • Ripped: Someone is ripped when they have very low body fat and muscle separation is visible and defined. i.e.: “That guy’s is ripped!”
  • Cut: Refers to the sharp lines of definition around muscles. i.e.: “I can see the cuts in your legs” or “she’s really cut”.
  • Jacked: Refers to a guy or girl who has a lot of muscle (like this guy). i.e.: “That guy is jacked!”
  • Juice: If you hear someone say they are on “juice” they aren’t talking about juicing fruits and vegetables, they’re talking about steroids.
  • Pump: This is when your muscle is so full of glycogen and water from training it, it actually will feel like it has been pumped up like a bicycle tire. It will feel tight to the touch and temporarily look swollen (in a good way).

Aerobic Exercise- Any rhythmic activity that increases the body's need for oxygen by using large muscle groups continuously for at least 10 minutes. The term aerobic means “with oxygen.”

Agonist Muscle- A muscle that is very effective in causing a certain joint movement. Also called the prime mover. On a biceps curl, the biceps is the agonist muscle that flexes the elbow joint.

Amenorrhea- The absence of menstruation, commonly found in women with a very low body fat percentage and/or exercise excessively.

Anaerobic Exercise- Short-lasting, high-intensity activity, where the demand for oxygen from the exercise exceeds the oxygen supply.

Antagonist muscle- A muscle that causes movement at a joint in a direction opposite to that of the joint’s agonist (prime mover).

Bar-A long straight bar (typically 45lbs) used to put plate weights, used traditionally for squatting and bench press.

Beta-blockers- Type of medication that reduces heart rate. Exercisers who take beta-blockers will have a lower heart rate at rest and during exercise, so the target heart rate formula cannot be used in this case.

Body Composition- Amount of fat vs. lean muscle tissue in the human body.

Body Mass Index (BMI)-Measure of the relationship between height and weight; calculated by dividing weight in kilograms by height in centimeters squared.  

Caffeine- A stimulant found in coffee, tea, chocolate, and some soft drinks that increase heart contractions, oxygen consumption, metabolism, and urinary output.

Calisthenics-Exercising using one’s own body weight which helps develop muscular tone.

Cardio- Short for Cardiovascular exercise, normally refers to a fat burning workout on a treadmill, elliptical, bike or aerobic class, although real cardiovascular exercise is designed primarily to work the heart and lungs.

Circuit Training- Takes the participant through a series of exercise stations (which could also include strength training), with relatively brief rest intervals between each station. The purpose is to keep the heart rate elevated near the aerobic level without dropping off. The number of stations may range from 4 to 10.

Collar- This is the attachment that secures the plate weights on a barbell or curl bar so the weight doesn’t slip off.

Concentric Muscle Action-Force produced while the muscle is shortening in length.

Continuous Training- This is the most common type of sustained aerobic exercise for fitness improvement, slowly adding more time to the workout to increase endurance.

Cooldown-Lowering of body temperature following vigorous exercise. The practice of cooling down after exercise involves slowing down your level of activity gradually.

Core-A muscle group comprised of the abdominals, lower back, obliques, and hips.

Cortisol- A hormone secreted by the adrenal gland that makes stored nutrients more readily available to meet energy demands. These hormone levels increase under stress, which can stimulate your appetite, leading to weight gain or difficulty losing weight.

Cross-training- An individualized combination of all aerobic-training methods, characterized by a variety of intensities and modes.

Curl Bar- The curved bar, known as the EZ Curl or preach curl bar, typically used for bicep curls, can normally weighs 25lbs.

Detraining Principle- This principle says that once consistent exercise stops, you will eventually lose the strength that you built up. Without overload or maintenance, muscles will weaken in two weeks or less.

DOMS (Delayed Onset Muscle Soreness)- Muscle soreness or discomfort that appears 12 to 48 hours after exercise. It is most likely due to microscopic tears in the muscle tissue, and it usually requires a couple of days for the repair and rebuilding process to be completed. The muscle tissue grows back stronger, leading to increased muscle mass and strength. To treat DOMS, increases blood flow to the muscle with low-intensity work, massage or hot baths. Increased water and protein can also help repair muscles. Staying still can make it worse.

Eccentric Contraction- A lengthening of the muscle during its contraction; controls the speed of movement caused by another force.

Electrolytes- Salts (ions) found in bodily fluids. Pertaining to exercise, your body loses electrolytes (sodium, potassium) when you sweat. These electrolytes need to be replaced to keep concentrations constant in the body, which is why many sports drinks include electrolytes.

Endorphins- Opiate-like hormones that are manufactured in the body and contribute to natural feelings of well-being.

Epinephrine- Also called adrenaline, a hormone that stimulates body systems in response to stress.

Fast-twitch Muscle Fibers-Fibers that are better-suited for high-force, short-duration activities because they contain more stores for anaerobic energy utilization.

Failure- When you cannot do one more rep. Reaching failure is believed to to produce muscle growth.

Fixed Resistance- Strength training exercises that provide a constant amount of resistance throughout the full range of motion. Examples include free weights and resistance bands.

Flexibility- The measure of the range of motion, or the amount of movement possible, at a particular joint.

Free Weights- Typically refers to dumbbells & barbells. Free weight exercises require more balance and engage more muscles than working out on machines. Free weights are more challenging to use, but highly recommended and offer a gym goer more versatility.

Heat Cramps- Muscle cramps that occur during or following exercise in warm or hot weather.

Heat exhaustion- A heat stress illness caused by significant dehydration resulting from exercise in warm or hot conditions; frequent precursor to heatstroke.

Heatstroke- A deadly heat stress illness resulting from dehydration and overexertion in warm or hot conditions; can cause body core temperature to rise from normal to 100 or 105 degrees Fahrenheit in just a few minutes.

High impact-Activities that place more stress on the bones and joints, where your limbs are actually making contact with the ground or other surface with force. Examples include walking, running, step aerobics, and sports that involve impact, like basketball or tennis.

HIIT- High-intensity interval training is another form of interval training. The exercise strategy alternates periods of short intense exercise with less-intense recovery periods.

Hypertrophy- An increase in cell size (girth), usually in reference to fat or muscle cells.

Hypothermia- A life-threatening condition in which heat is lost from the body faster than it is produced.

Interval Training- Repeated intervals of exercise interspersed with intervals of relatively light exercise. This type of training provides a means of performing large amounts of high-intensity exercise in a short period of time.

In The Pocket (ITP) - Refers to staying on program and not ego lifting. Typically used by powerlifters.

Isokinetic Exercise- Exercise in which the rate of movement is constantly maintained through a specific range of motion even though maximal force is exerted.

Isometric Exercise- Any activity in which the muscles exert force but do not visibly change in length. For example, pushing against a wall or carrying a bag of groceries.

Isotonic Exercise- Any activity in which the muscles exert force and change in length as they lift and lower resistance. For example, bicep curls or leg extensions.

Ketosis- A condition in which the body adapts to prolonged fasting or carbohydrate deprivation by converting body fat to ketones, which can be used as fuel for some brain activity. The real danger in ketosis is that ketones are acidic, and high levels of ketones make the blood abnormally acid.

Lactic Acid- Once thought of as a waste substance that builds up in the muscles when they are not getting enough oxygen, leading to muscle fatigue and soreness. Now, experts believe that lactic acid is beneficial to the body, acting as a "fuel" to help people continue high-intensity (anaerobic) exercise even when oxygen consumption is low.

Lean Mass- Total weight of your muscle, bone, and all other body organs. (Everything in the body besides fat.)

Low Impact- Activities that place less stress on the bones and joints. These are better for people with joint pain, and overweight individuals whose weight can hurt their joints. Examples include swimming, elliptical, cycling, and other activities where your feet (or other body parts) aren’t touching the ground with force or where you are somehow supported.

Max VO 2- (V02 Max) Highest amount of oxygen one can consume during exercise. The higher this number, the more you are cardiovascularly fit and capable of increased levels of intensity.

Mesomorph- A body shape characterized by a large chest, long torso, solid muscle structure, and significant strength.

Moderate Intensity- Activities that range from 40-60% of max heart rate. These activities cause a slightly increased rate of breathing and feel light to somewhat hard. Individuals doing activity at this intensity can easily carry on a conversation.

Muscle Fibers-Individual muscle cells that are the functional components of muscles.

Muscular Endurance- The ability of the muscle to perform repetitive contractions over a prolonged period of time.

Muscular Strength- The ability of the muscle to generate the maximum amount of force.

Negatives- Negative training is when the muscle lengthens during an exercise, called an eccentric contraction. For instance, on a bicep curl, the negative movement is when you are bringing the weight back down. Concentric contraction is what we think of when we flex our muscle, or shorten the muscle (like the beginning of a bicep curl). The negative movement is believed to be a crucial part of muscle development.

Obesity- A weight disorder generally defined as an accumulation of fat beyond that considered normal for a person based on age, sex, and body type.

One-Rep Max (1 RM)- The amount of weight/resistance that can be lifted or moved once, but not twice; a common measure of strength.

Opposing Muscles- Muscles that work in opposition to the ones you are training. For example, the bicep is the opposing muscle to the triceps; the hamstring is the opposing muscle to the quadriceps.

Osteoporosis- A disease characterized by low bone mass and deterioration of bone tissue, which increases risk of fracture.

Overload Principle-This principle says that in order to train muscles, they must work harder than they are accustomed to. This “overload” will result in increased strength as the body adapts to the stress placed upon it.

Overuse Injuries- Injuries that result from the cumulative effects of repetitive (day-after-day) stresses placed on tendons, muscles, and joints.

Physical Fitness-The ability to perform regular to vigorous physical activity without great fatigue.

Pilates- Exercise programs that combine dynamic stretching with movement against resistance.

Plateau- Point in an exercise program where no additional progress is being made (gains in strength, weight loss, increased endurance, etc). One way to break through a plateau is to change the kind of activity you are doing or something about your current activity- adding hills, increasing speed, increasing distance, etc.

Primary Prevention-Actions designed to stop problems before they start.

Pronation-To turn or rotate (the foot) so that the inner edge of the sole bears the body's weight.

Plyometric Training- Exercises that enable a muscle to reach maximal force production in as short a time as possible. For example, jumping from a 3 ft. stool to the ground and immediately springing back up to another stool.

Pyramiding- Doing sets of downward or upward scaling of reps or weight. i.e 4 sets by 12-10-8-6, or 6-8-10-12Intervals: Interval training is when you train at a low intensity for a period of time, followed by a high intensity. (I love interval training!)

Rate of perceived exertion (RPE)- Scale of 1-10 that rates how you are feeling (both physically and mentally) as it relates to exercise fatigue.

Recovery- Refers to rest between exercises. Short recovery is best for fat burn and conditioning, long recovery is best for power lifting and bulking

Repetition- The number of times an exercise is repeated within a single exercise “set.”

Resistance Training- Any exercise using resistance, like weight or elastic bands.

Resting HR- Rate at which your heart beats at rest (while sitting or being inactive). Low resting heart rates are a good measure of health and fitness.

Resting Metabolic Rate (RMR)- Number of calories expended to maintain the body during resting conditions. Also referred to as basal metabolic rate.

Set- A basic unit of a workout containing the number of times (repetitions) a specific exercise is done (e.g. do 3 sets of 5 repetitions with 100 pounds).

Shin Splint-Generic term used to describe pain in the lower leg, either on the medial (inside) or lateral side (outside) of the shin bone.

Slow-twitch Muscle Fibers- Fibers that are better-suited for low-force, long duration activities because they possess more endurance enzymes.

Specificity of Training Principle- This principle says that only the muscle or muscle group you exercise will respond to the demands placed upon it. By regularly doing curls, for example, the muscles involved (biceps) will become larger and stronger, but curls will have no effect on the muscles that are not being trained. Therefore, when strength training, it is important to strengthen all of the major muscles.

Spot- When someone assists another person with an exercise. ie: “Can you spot me?” or “I need a spotter.”

Static Stretching- A low force, high-duration stretch where the muscle is held at the greatest possible length for up to 30 seconds.

Strength Training (resistance training)- The process of exercising with progressively heavier resistance for the purpose of strengthening the musculoskeletal system.

Super Set- Refers to a combination of complimentary exercises done back to back in one “superset” with little to no rest. For instance, “I did a superset of shoulder presses and lateral raises”

Tabata- Tabata training is a highly effective style of interval training, doing an exercise for 20 seconds on and 10 seconds of rest for 8 rounds, which totals 4 minutes.

TalkTest- Method to ensure you are working out at a level where you can answer a question but not comfortably carry on a conversation. This is a good intensity level for weight loss and improved physical fitness.

Tapering- The process athletes use to reduce their training load for several days prior to competition.

Target Heart Rate (THR)- The recommended range is 60-85% of your maximum heart rate. It represents a pace that ensures you are training aerobically and can reasonably be maintained.

Tension Principle- This principle says that tension is created by resistance, which can come from weights, bands, machines, or body weight.

Testosterone-The steroid hormone produced in the testes; involved in the growth and development of muscle mass. Since men have more testosterone than women, they are able to gain muscle mass more easily.

Thyroid-Endocrine gland located in the neck that secretes T3 and T4 (hormones), which increase metabolic rate.

Type I Muscle Fibers-Fibers that contain large numbers of oxidative enzymes and are highly fatigue resistant (more prevalent in endurance athletes).

Type IIA Muscle Fibers- Fibers that contain biochemical and fatigue characteristics that are between Type IIB and Type I fibers (the best of both worlds).

Type IIB Muscle Fibers- Fibers that have a relatively small number of mitochondria, a limited capacity for aerobic metabolism, and are less resistant to fatigue than slow fibers (more prevalent in sprinters and powerlifters).

Vigorous-Intensity-Activities above 60% of max heart rate. These activities cause an increased rate of breathing and sweating.

Warm Up- To prepare for an athletic event (whether a game or a workout session) by exercising, stretching, or practicing for a short time beforehand.

Yoga-A variety of Indian traditions geared toward self-discipline and the realization of unity; includes forms of exercise widely practiced in the West today that promote balance, coordination, flexibility, and meditation.