Fitness glossary

AMRAP is a high-intensity training format: do as many reps or rounds as possible in a fixed time. CrossFit favorite.

ATP is the universal energy currency of the body. Every muscle contraction, every cellular function depends on it.

Discover what abduction is in bodybuilding, this movement which moves a limb away from the central axis of the body to develop the stabilizing muscles.

Active recovery uses light activity to speed muscle recovery. Find out how to effectively integrate it into your routine.

Adduction is a movement that brings a body part toward the body's midline. Opposite of abduction.

The aerobic system produces energy with oxygen, fueling long-duration efforts. It's the foundation of endurance and recovery.

The anabolic window is the post-workout period considered ideal for nutrition. The reality: it's much longer than thought.

The anaerobic system produces energy without oxygen — for explosive, intense efforts. Limited but powerful, it fuels strength and sprints.

BCAAs are 3 essential branched-chain amino acids: leucine, isoleucine, valine. Discover their real usefulness, timing, and whether you actually need them.

BMI (Body Mass Index) is a quick health screening tool, but it doesn't account for body composition. Limited but useful.

BMR (Basal Metabolic Rate) is your resting metabolism — the calories burned just to stay alive. Learn how to calculate and optimize it for your fitness goals.

Beta-alanine is an amino acid that raises muscle carnosine and can help buffering in efforts of ~1–4 minutes; tingles (paresthesia) are common.

Block periodization concentrates training into focused blocks (accumulation, intensification, realization) with clear priorities.

BFR training uses cuffs to partially restrict blood flow so lighter loads can still stimulate hypertrophy — with safety constraints.

Body fat percentage measures the share of fat in your total body mass. A key indicator of body composition.

Body recomposition is gaining muscle and losing fat at the same time. Possible but slow — discover the conditions for success.

Bodyweight training uses your own body as resistance. No equipment, anywhere, scalable to any level.

Caffeine is a stimulant that can raise alertness and training performance; dose and timing matter for sleep and anxiety.

Calisthenics builds strength and skill primarily with bodyweight patterns (push-ups, pull-ups, dips, levers) and progressive variations.

Caloric maintenance is the calorie level keeping your weight stable. Foundation of any nutritional plan.

A caloric surplus means consuming more calories than you burn. Mandatory mechanism for serious muscle building.

A caloric deficit means consuming fewer calories than you burn. It's the only proven mechanism for fat loss. Learn how to set yours up properly.

Calories measure the energy provided by food. Understanding your caloric needs is the foundation of every fitness goal.

Carbohydrates are the main source of energy for intense training. Discover your needs, the different types and their role in performance.

Casein is a slower-digesting dairy protein, often used between meals or at night to help hit daily protein targets.

Circuit training chains several exercises with little rest. Ideal for burning calories and improving cardiovascular fitness while keeping muscle.

Cluster sets break a set into mini-bouts with short intra-set rests to keep bar speed and load high — useful for strength and power.

Collagen is a structural protein; supplements may support connective tissue goals but are incomplete for total muscle protein needs.

A compound exercise trains several joints and muscle groups at once (squat, hinge, press, pull) — high return for strength and hypertrophy.

The concentric phase is the lifting movement, where the muscle shortens under load. It's the active phase that produces force.

A cool-down is light activity after hard work to gradually lower intensity; useful for feel and transition, not magic recovery.

Creatine is the most studied supplement in sports nutrition, proven to boost strength, power and muscle mass. Learn dosage, timing and real benefits.

A cutting phase is a period of caloric deficit aimed at losing fat while preserving muscle. Discover how to do it without losing your hard-earned gains.

DOMS is the muscle soreness that appears 24-72h after exercise. Discover its causes, how to manage it, and what it really means for your progress.

Deload is an active recovery week where you intentionally reduce volume and intensity to allow your body to fully recover and come back stronger.

Dietary fiber supports satiety, digestion and cardiometabolic health; useful in fat-loss adherence plans.

A dropset extends a set by reducing the load when failure hits. Powerful intensification method for hypertrophy.

EMOM (Every Minute On the Minute) is a training format where you start a set at the top of each minute and rest until the next.

The eccentric phase is the lowering movement, where the muscle lengthens under tension. It's the most damaging phase and the key driver of hypertrophy.

Electrolytes (sodium, potassium, magnesium…) are minerals that conduct electrical signals and help fluid balance, especially with heavy sweating.

Exercise selection is choosing movements that fit the goal, equipment, anatomy and skill — the foundation of a good program.

Extension is the anatomical movement that increases the angle between two body segments. Opposite of flexion.

Fat mass is the total weight of fat tissue. Essential for survival, but excess harms health and aesthetics.

Muscle fibers are the cells that make up muscle. Two main types — Type I (slow) and Type II (fast) — define your physical potential.

Flexion is the anatomical movement that decreases the angle between two body segments. Opposite of extension.

Foam rolling is a myofascial self-massage technique to release muscle tension. Find out how to use it effectively to improve recovery and mobility.

For Time is a training format where you complete a fixed amount of work as fast as possible. Race against the clock.

A full body program trains all major muscle groups in each session, 2-4 times per week. Ideal for beginners and strength training.

GVT is a high-volume hypertrophy scheme classically built around 10×10 on big lifts with short rests — very fatiguing.

Glycogen is the storage form of carbohydrate in muscle and liver — the primary fuel for hard training.

HIIT (High-Intensity Interval Training) alternates short hard efforts with recovery to improve fitness and calorie burn in less time.

Hydration is maintaining fluid balance for performance, cognition and recovery — water plus electrolytes when sweat losses are high.

Muscle hypertrophy is the increase in muscle fiber size. It's the primary mechanism behind muscle growth from resistance training.

Hypertrophy training aims to maximize muscle growth using moderate loads (65-85% 1RM) with 8-15 repetitions per set.

Intermittent fasting restricts eating to time windows; fat loss still depends mainly on calorie balance and protein.

Intra-workout refers to nutrition consumed during training to maintain energy, hydration and performance on long sessions.

An isolation exercise targets mainly one joint and one muscle group (curl, lateral raise, leg extension) to add local volume or correct imbalances.

Isometric contraction is when the muscle produces tension without changing length. No visible movement, intense work.

LISS (Low-Intensity Steady State) is continuous easy cardio at a conversational pace — useful for recovery, aerobic base and extra calorie burn.

A lean bulk is a slow, controlled surplus aimed at maximizing muscle gain while limiting fat gain.

Lean mass is everything in your body except fat: muscles, bones, organs, water. A real performance indicator.

Linear periodization progresses from higher volume/lower intensity toward lower volume/higher intensity over weeks.

Lipids are essential for hormone production and vitamin absorption. Discover your needs, the right sources and their role in bodybuilding.

A macrocycle is the global organization of your training over 3-12 months. The highest level of periodization, your annual game plan.

Macronutrients are the 3 main types of nutrients: proteins, carbohydrates and lipids. Their balance is crucial for performance and body composition.

Maintenance is the calorie level at which your weight remains stable. The neutral baseline for any nutritional strategy.

Mass gain (or bulk) is a controlled caloric surplus phase aimed at building muscle. Discover how to do it without gaining excess fat.

Meal timing is the strategic distribution of your meals around training and through the day to optimize performance and recovery.

A mesocycle is a 4-8 week training block with a specific objective (hypertrophy, strength, peak, deload). The cornerstone of periodization.

A microcycle is the smallest planning unit in bodybuilding: generally 1 week of training. This is your weekly routine.

Mind-muscle connection is the intentional focus on feeling the target muscle contract — useful for hypertrophy technique and isolation work.

Mobility is the ability to actively control range of motion. Find out how to improve your mobility to optimize your performance.

Muscle failure is the point where you cannot complete another clean rep with the target technique — RIR 0 / RPE 10.

Muscle mass is the total weight of muscles in the body. Key indicator of strength, metabolism, and longevity.

Muscular endurance training develops the ability to sustain prolonged effort. Light loads, high reps, short rests.

Muscular endurance is a muscle's capacity to sustain repeated or prolonged contractions without excessive fatigue. Foundation of many sports.

Muscular strength is the maximum force a muscle (or group) can produce. The fundamental physical quality of any athlete.

Myo-reps is an intensification method: an activation set near failure, then mini-sets with short rests to accumulate effective reps.

NEAT is the energy you burn through all your daily activities outside of training. The most underestimated lever of your body composition.

1RM is the heaviest load you can lift for one clean repetition — the reference for strength programming and percentages.

Omega-3 fats (EPA/DHA) support general health; in athletes they are discussed for recovery and inflammation — food first, then supplements if needed.

Overreaching is a short-term performance drop from hard training that recovers with planned rest — unlike prolonged overtraining.

Overtraining is a prolonged performance drop from excess stress without enough recovery — rarer than simple overreaching.

A PR (Personal Record) is your best performance ever on a movement. The fundamental progress marker.

Passive recovery links on complete rest to allow the body to regenerate. Find out when and how to use it effectively.

Periodization is the cyclical organization of training into distinct phases to optimize progression, prevent plateaus, and avoid injuries.

A plateau is a period of stagnation despite consistent training. Identifying the cause is the key to breaking it.

The post-workout is the nutrition right after training to optimize recovery and growth. Protein, carbs, hydration.

Power is force × velocity — producing force quickly. Trained with intent, moderate loads moved fast, jumps/throws, and adequate rest.

Powerlifting is a strength sport focused on maximal squat, bench press and deadlift — programming revolves around heavy compounds and peaking.

The pre-workout is the meal or supplement taken before training to optimize performance. Energy, focus, and pump.

Progressive overload is the foundational principle of training: gradually increasing the demand on your muscles to keep gaining strength and size.

Protein is the essential macronutrient for building and repairing muscle. Discover your needs, the best sources and the optimal timing.

Protein powders are concentrated protein supplements. Practical for hitting daily protein needs.

The Push/Pull/Legs program divides the workout into 3 types of sessions: push (chests/shoulders/triceps), pull (back/biceps) and legs. Optimal for all levels with frequency 2x/week per muscle.

RIR (Reps in Reserve) measures how many reps you have left before failure. Modern, intuitive tool to manage intensity.

RPE (Rate of Perceived Exertion) is a 1-10 scale to measure subjective effort. Essential tool for managing intensity.

Range of motion (ROM) is the amplitude through which a joint or muscle can move during an exercise. Crucial for hypertrophy and joint health.

A refeed is a planned short increase in calories (often carbs) during a fat-loss phase to support training, hormones and adherence.

A rep is one complete execution of an exercise. The rep range determines whether you primarily develop strength, hypertrophy, or muscular endurance.

RTF means performing reps until no clean rep remains; useful sparingly for hypertrophy, costly if overused on heavy compounds.

Rest between sets is critical and depends on the goal. Strength: 3-5 min. Hypertrophy: 1-3 min. Endurance: 30-60 sec.

A rest day is planned time off hard training so adaptation can occur; it can be full rest or very light activity.

Rest-pause is an intensification method using ultra-short pauses to extend a set. Powerful tool for hypertrophy.

The sarcomere is the basic contractile unit of muscle. Composed of actin and myosin, it produces all your movements.

A series (or set) is a group of consecutive reps without rest. The basic unit of training programming.

Sleep is the most underrated training variable. It's during sleep that recovery, muscle building, and hormonal regulation happen.

A split workout involves dividing muscle groups over different days. The classic split trains each muscle once a week for 5-6 days.

Strength training aims to develop maximal strength using heavy loads (80-95% of 1RM) with few repetitions (1-6 reps).

Stretching improves flexibility and range of motion. Learn about the different types and how to effectively incorporate them into your routine.

A superset chains two exercises with no rest between them. Time-efficient method that boosts intensity and density.

TDEE (Total Daily Energy Expenditure) represents your total daily energy expenditure. Find out how to calculate it precisely to optimize your results.

TUT (Time Under Tension) measures the total time the muscle is under load during a set. Key variable for hypertrophy.

Tabata is a 4-minute HIIT protocol: 20 seconds max effort, 10 seconds rest, 8 rounds. Maximum efficiency in minimum time.

Tempo is the controlled speed of each phase of a movement. Powerful tool to maximize stimulus and control.

Training density measures the amount of work done per unit of time. Increase it to boost intensity and metabolic stress.

Training frequency defines how many times per week you work a muscle. Discover the optimal frequency to progress.

Bodybuilding intensity measures the difficulty of the effort. Find out how to calculate it with % of 1RM, RPE, and RIR.

Training volume represents the total amount of work performed. Discover the optimal volumes per muscle per week to progress.

Type I fibers (slow-twitch) are endurance-oriented muscle fibers. Resistant to fatigue, they sustain prolonged efforts.

Type II fibers (fast-twitch) are powerful muscle fibers optimized for explosive efforts. Essential for strength and power.

Undulating periodization varies volume and intensity frequently (daily or weekly) instead of long linear phases.

The Upper/Lower program divides training into upper body and lower body sessions over 4 days per week. Perfect balance between frequency (2x/week) and volume for all levels.

VO2 max is the maximum amount of oxygen your body can use during intense exercise. It's the gold standard of cardiovascular fitness.

A warm-up raises temperature, primes the nervous system and rehearses the session patterns before hard sets.

Whey is a fast-digesting dairy protein powder, rich in leucine — a convenient way to hit daily protein targets.

Zone 2 is a moderate aerobic intensity (often ~60–70% HRmax) where you can talk in full sentences — foundation of endurance base.