This glossary of terms relevant to bodybuilding continues with the letters O and P — one of the densest sections so far. You’ll find programming concepts like periodization and progressive overload, energy system basics like the phosphagen system, and a long list of exercises and equipment worth knowing by name, from the power clean and power rack to the pull-up, push-up, and pec deck. There are also a few terms, like the pump and posing, that capture what makes bodybuilding feel different from general fitness. Browse the full list below, or use the navigation links to jump straight to a specific term.
- Olympic barbell
- The most specialized type of barbell used in weightlifting, weighing 45 pounds (20 kg) and constructed from spring steel designed to flex slightly under heavy load while remaining structurally sound. → Barbells: benefits & drawbacks
- Olympic weightlifting
- The sport of weightlifting contested at the Olympic Games, as well as at national and international competitions, consisting of two lifts: the snatch and the clean and jerk. Olympic weightlifting differs from powerlifting in both the lifts performed and the emphasis on speed and technique. → Bodybuilding, powerlifting, weightlifting, strongman: what’s the difference?
- Open-chain exercise
- An exercise in which the hand or foot is free to move through space rather than being fixed against a stationary surface — for example, a leg extension or a biceps curl. Open-chain exercises typically isolate a single joint, in contrast to closed-chain compound movements like the squat.
- Origin
- The point where a muscle attaches to the bone, located closest to the body’s midline or center — as opposed to the insertion, which is the attachment point furthest from the midline. → Muscle anatomy basics: origin, insertion & innervation
- Outer pectoral
- The outer portion of the pectoralis major, located toward the shoulder and armpit. Exercises performed with a wider grip or arm path, such as wide-grip bench presses or cable flyes, tend to place relatively more emphasis on this region.
- Overhand grip
- Also known as a pronated grip, this grip involves holding the bar with the palms facing down and the knuckles toward the front or top of the bar — used, for example, in the reverse barbell curl or the barbell shrug. → Handgrip types & width in strength training
- Overload (overload principle)
- The training principle stating that a muscle must be progressively challenged beyond what it is already accustomed to in order to continue adapting and growing. For bodybuilders, this stress is most often applied in the form of added weight, though increased reps, sets, or reduced rest can also overload a muscle. → Progressive overload: the most important bodybuilding concept
- Overreaching
- A scientific term for training that temporarily pushes the body beyond its current capacity to recover and adapt, usually from too much volume, intensity, or frequency. Overreaching is the stage just before overtraining; if it’s followed by adequate recovery, an athlete can often rebound with rapid gains in strength and muscle mass rather than suffering the negative effects of true overtraining.
- Overtraining
- The state reached when an athlete overreaches for too long without sufficient recovery, causing the body to stop progressing and even lose previous gains in strength and muscle mass. Early signs from excessive load can include a higher resting heart rate, trouble sleeping, and increased sweating, while overtraining from excessive volume or frequency can show up as a lower resting heart rate, digestive issues, and persistent fatigue. → Signs and symptoms of overtraining
- Oxidative stress
- An imbalance between the production of reactive molecules called free radicals and the body’s ability to neutralize them with antioxidants. Intense exercise temporarily increases oxidative stress, and while the body adapts to this over time with regular training, chronic excessive oxidative stress is linked to slower recovery and increased disease risk.
- Passive stretching
- A form of stretching in which an external force — typically a training partner, but sometimes a strap or other prop — moves a joint through its range of motion, allowing for a greater stretch than could be achieved unassisted.
- Peak
- The absolute high point of competitive condition an athlete achieves, referring either to the sharpness and fullness of a specific muscle (often the biceps) or to a bodybuilder’s overall condition on contest day. A bodybuilder who has “peaked” displays full, vascular muscles at a very low body fat percentage.
- Pecs
- A common slang term referring to the pectoralis muscles of the chest. → Mastering lower chest exercises for a chiseled pectoralis major
- Periodization
- The systematic planning and manipulation of training variables — such as volume, intensity, and exercise selection — over a defined period ranging from weeks to years. Periodization is widely used by competitive athletes to peak for a specific event or competition while managing fatigue and reducing injury risk.
- Periodized program
- A training program built using periodization principles, typically organized into distinct macrocycles, mesocycles, and microcycles, each with its own focus, in order to build toward a specific peak in performance or physique.
- Phosphagen system
- Also called the ATP-PC system — the body’s fastest energy system, relying on stored ATP and phosphocreatine to fuel maximal efforts lasting roughly up to 10 seconds, such as a single heavy lift or a short sprint, before other energy systems take over.
- Phosphocreatine (PCr)
- An energy-rich compound stored in muscle tissue that plays a critical role in rapidly regenerating ATP during short, intense bursts of effort, such as a heavy single rep or a sprint.
- Plantar flexion
- Moving the top of the foot downward, away from the shin — as in pointing the toes, or the upward phase of a calf raise. Plantar flexion is the opposite of dorsiflexion.
- Plate-loaded machine
- A resistance machine that uses standard weight plates, loaded directly onto pegs or a lever arm, rather than a fixed weight stack. Plate-loaded machines often allow for a more natural strength curve and heavier loading than stack-based machines.
- Plateau
- A period during training when no measurable progress is being made, typically occurring after extended stretches of repetitive, unvaried training. Plateaus are usually broken by deliberately changing training variables — exercises, rep ranges, volume, or intensity — to provide a new stimulus. → Hitting and overcoming a weightlifting plateau → Breaking a weight loss plateau
- Plyometric box jump
- A jump training exercise in which the lifter explosively jumps from the ground onto an elevated box or platform, developing lower-body power and rate of force development. It is one of the most common plyometric exercises used outside of specialized sports training.
- Plyometrics
- Exercises involving rapid, repeated stretching and contracting of a muscle — also called jump training — designed to increase explosive muscular power rather than pure strength or size. → What is plyometric training: definition and exercises
- Posing
- The art of displaying the physique during a bodybuilding contest, consisting of mandatory poses used to directly compare competitors, and free posing, where an athlete combines their best poses to highlight strengths, minimize weaker areas, and showcase personality on stage. → Bodybuilding posing routine
- Positive phase of repetition
- The concentric portion of a repetition — for example, pressing the barbell off the chest during a bench press, or curling the weight upward during a biceps curl. The positive phase is the counterpart to the negative, or eccentric, phase.
- Post-workout meal
- A meal or snack consumed after training, typically containing protein and carbohydrates, intended to support muscle recovery and replenish glycogen stores. While the exact timing window is less critical than once believed, getting adequate post-workout nutrition within a few hours remains a sound practice. → Optimum post-workout nutrition
- Posterior chain
- The group of muscles running along the back of the body, including the glutes, hamstrings, calves, and lower-back muscles. The posterior chain plays a major role in hip extension and is heavily involved in deadlifts, good mornings, and sprinting. → What is the posterior chain? Muscles, functions, benefits & best exercises
- Posterior deltoid
- The rear portion of the deltoid muscle, located at the back of the shoulder. The posterior deltoid is involved in horizontal pulling and reverse-fly type movements, and is often a relatively underdeveloped area compared with the front and side delts. → Posterior deltoid: functional anatomy guide
- Poundage
- Another term for the total weight being lifted — whether on a barbell, dumbbell, or weight stack machine.
- Power
- The ability to exert maximal force in minimum time — essentially, how quickly a given lift can be performed. Muscular power combines the speed of movement with the force generated, and is a key quality in explosive sports and Olympic-style lifts. → Muscular power: defined, explained & how to train it
- Power clean
- An Olympic-lift variation in which a barbell is explosively pulled from the floor and caught on the shoulders in a partial squat, emphasizing speed and power production through the hips and legs over the deeper receiving position used in a full clean. → Explosive lifts: power clean
- Power rack
- A free-standing piece of equipment with adjustable vertical supports and safety bars, used to perform squats, bench presses, and overhead presses safely at heavy loads without requiring a spotter. → Power rack: best-selling piece of home gym equipment
- Powerlifting
- A competitive strength sport featuring three lifts: the squat, bench press, and deadlift, contested in a variety of weight and age classes for both men and women at national and international levels. → Bodybuilding, powerlifting, weightlifting, strongman: what’s the difference?
- Pre-workout (supplement)
- A supplement, typically taken 15 to 45 minutes before training, designed to increase energy, focus, and performance during a workout. Common ingredients include caffeine, beta-alanine, and citrulline, though formulas vary widely between products. → Pre-workout supplements: do you need them?
- Preexhaust
- A training technique in which a single-joint, isolation exercise is performed before a related multi-joint, compound exercise, in order to pre-fatigue a specific muscle so it becomes the limiting factor during the compound movement that follows. → Pre-exhaustion training strategy: benefits, drawbacks & tips
- Primary exercise
- An exercise most directly aligned with a lifter’s specific training goals, typically a compound movement targeting the muscle groups they are most focused on developing. Primary exercises are usually programmed first in a session, when energy and focus are highest.
- Progressive overload
- The gradual, ongoing increase of training stress over time — through added weight, reps, sets, or other variables — required to keep forcing muscles and the nervous system to adapt. Progressive overload is widely considered the single most important principle for long-term strength and muscle gain. → Progressive overload: the most important bodybuilding concept
- Pronated grip
- A grip in which the palms face down and away from the body, with the thumbs pointing toward each other — used, for example, in a close-grip pulldown to the front. → Handgrip types & width in strength training
- Pronation
- Rotation of the wrist (or forearm) inward, so that the palm turns to face downward or backward.
- Prone
- Lying face-down, horizontally on the abdomen — the position used in exercises such as prone leg curls or prone Y-raises.
- Proportion
- A term describing the relative size of one muscle group compared with the rest of the body. A bodybuilder with good proportions has muscle groups that appear balanced and harmonious in size relative to one another, rather than some areas appearing disproportionately large or underdeveloped. → Achieving the symmetrical ideal in bodybuilding
- Protein
- A nutrient made up of long chains of amino acids, used primarily by the body to build and repair muscle tissue, as well as to produce hormones and enzymes. Adequate protein intake is essential for muscle growth and recovery from training. → Protein intake calculator: how much protein do I need daily?
- Protein synthesis
- The biological process by which cells build new proteins, including the muscle proteins responsible for growth and repair after training. Muscle protein synthesis is stimulated by resistance training and adequate protein intake, and must exceed muscle protein breakdown over time for net muscle growth to occur. → Muscle protein synthesis (MPS): the science of building muscle
- Pull-up
- A bodyweight exercise performed by gripping an overhead bar and pulling the body upward until the chin clears the bar, primarily targeting the lats, biceps, and upper back. The pull-up is considered one of the best overall indicators of relative upper-body pulling strength. → Wide-grip pull-ups: the king of back width and vertical pulling strength
- Pump
- A term used by bodybuilders to describe the temporary swelling muscles undergo during a workout. The pump occurs because repeated muscle contractions produce metabolic byproducts that draw extra water into the muscle, increasing cell volume and creating a temporary size increase that fades once those byproducts clear.
- Push-pull-legs (PPL)
- A popular training split that divides workouts into pushing movements (chest, shoulders, triceps), pulling movements (back, biceps), and leg movements (quads, hamstrings, glutes, calves), typically repeated twice within a training week. → 4-week push-pull-legs workout routine for beginners
- Push-up
- A bodyweight pressing exercise performed face-down, lowering and raising the body by bending and straightening the arms, primarily targeting the chest, shoulders, and triceps. Variations such as incline, decline, and diamond push-ups shift emphasis between different muscle areas. → Basic chest push-ups: complete guide to technique, benefits & variations
- Pyramiding
- A training technique in which weight is increased for the first several sets of an exercise and then decreased for the remaining sets. A “half-pyramid” variation involves only the ascending or only the descending portion rather than both. → Pyramid training systems in weightlifting
