The next stop in the bodybuilding glossary covers terms starting with E and F — covering body types like ectomorphs and endomorphs, training concepts like eccentric movement and muscle failure, and nutrition basics like essential fatty acids and fiber. Browse the full list below, or jump straight to a term using the navigation links.
- ECA, ECA stack
- An abbreviation for ephedrine, caffeine, and aspirin — a combination once popular as a fat-loss and energy-boosting stack. ECA stacks carry significant cardiovascular risks and ephedrine-based products are banned or restricted in many countries. → Ephedra, ephedrine, and ECA stack: everything you need to know
- Eccentric
- Describing a muscle action in which the muscle lengthens while still producing force — for example, the controlled lowering phase of a biceps curl. Eccentric action is the counterpart to concentric action, and training that emphasizes the eccentric phase is often linked to greater muscle damage and soreness. → Eccentric weight training: definition, pros & cons
- Ectomorphs
- A body type characterized by long, thin bones, naturally low body fat levels, and difficulty gaining muscle mass. Ectomorphs typically have fast metabolisms and benefit from higher calorie intakes and compound-focused training to support muscle growth. → The 3 somatotypes explained: ectomorph, mesomorph, endomorph
- Elbow
- The hinge joint connecting the upper arm (humerus) to the forearm (radius and ulna), allowing flexion and extension of the arm. The elbow is heavily involved in pressing, pulling, and curling movements, and is a common site of overuse injury such as tendonitis.
- Endomorphs
- A body type characterized by larger bone structure and a natural tendency to carry more body fat. Endomorphs often build muscle relatively easily but may need to pay closer attention to diet and cardio to manage body fat levels. → The 3 somatotypes explained: ectomorph, mesomorph, endomorph
- Endorphins
- Chemicals released by the brain in response to pain or stress, often referred to as the body’s “natural opiates.” Endorphins reduce the perception of pain and are partly responsible for the post-workout sense of wellbeing sometimes called a “runner’s high.”
- Endurance
- The ability of a muscle or the cardiovascular system to sustain repeated effort over an extended period without fatiguing. Muscular endurance is typically trained with higher repetition ranges and shorter rest periods than pure strength training. → Muscular endurance in strength training
- Energy systems
- The metabolic pathways the body uses to produce ATP for muscle contraction during exercise. The three primary energy systems — phosphocreatine, glycolytic, and oxidative — contribute in different proportions depending on the intensity and duration of the activity. → Understanding energy systems: aerobic vs. anaerobic
- EPOC
- Short for excess post-exercise oxygen consumption — see the full entry under “Excess post-exercise oxygen consumption (EPOC)” below.
- Erector spinae
- A group of muscles running along the length of the spine that extend the back and help maintain upright posture. The erector spinae play a key stabilizing role during deadlifts, squats, and other heavy compound lifts. → The anatomy of lower back muscles: erector spinae
- Essential amino acids
- Amino acids that cannot be synthesized by the body from other amino acids and must therefore come from the diet: leucine, isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, and histidine. Complete protein sources contain all of these in sufficient amounts. → Amino acid supplements for bodybuilding
- Essential fatty acids (EFAs)
- Fats with anti-catabolic, anti-lipolytic, and antioxidant properties that the body cannot produce on its own. EFAs positively influence cholesterol levels and support the muscle-building and fat-loss process. Omega-3 fatty acids, found in fish oil and flaxseed oil, are a well-known source of EFAs. → Essential fatty acids: omega 3 & 6
- Estrogen
- The primary female sex hormone, responsible for regulating sexual development and reproductive function. Excess estrogen is linked to fat gain and water retention, while estrogen deficiency can contribute to memory problems, mood swings, and irritability. Regular exercise helps support healthy hormonal balance. → Estrogen and strength training: everything women need to know
- Excess post-exercise oxygen consumption (EPOC)
- The elevated rate of oxygen consumption that persists above resting levels after a workout ends, as the body works to restore itself to its pre-exercise state. EPOC is sometimes referred to informally as the “afterburn effect,” and tends to be greater following high-intensity training. → The HIIT advantage: excess post-exercise oxygen consumption
- Exercise
- In general terms, any form of physical activity that raises the heart rate and respiratory rate. In a bodybuilding context, an exercise refers to one specific movement targeting one or more muscle groups — for example, the bench press, squat, or biceps curl. → Types of lifting exercises
- Extension
- The act of straightening a joint — for example, the elbow extends during a triceps pressdown. Extension is the opposite of flexion. → Cable rope overhead triceps extension
- EZ-curl bar
- A short, S-shaped barbell used for exercises such as biceps curls and lying triceps extensions. Its angled grips place less stress on the wrists and forearms compared with a straight barbell. → EZ-bar preacher curl: the ultimate biceps isolation exercise
- Failure
- The point during a set at which a muscle can no longer complete another repetition with proper form, despite maximal effort. Training to failure is a common technique for maximizing muscle stimulus on a given exercise, though it is not necessary on every set to continue making progress. → Lifting to muscle failure in weight training
- False grip
- A grip in which the thumb stays alongside the fingers on the same side of the bar, rather than wrapping around it as in a standard grip. This grip is generally not recommended for pressing movements since the bar can more easily slip out of the hands.
- Fascia
- A thin layer of connective tissue that surrounds and supports muscles, organs, and other structures throughout the body. Fascia plays a role in flexibility and movement quality, and has become a growing focus in recovery practices such as foam rolling and soft-tissue work.
- Fast-twitch muscle fibers
- Muscle fibers that contract quickly and powerfully but fatigue relatively fast, with limited endurance. Fast-twitch fibers are best developed through strength training using heavy weight and low reps, or lighter weight moved explosively. → Types of muscle fibers: slow-twitch vs. fast-twitch
- Fat loss
- The process of reducing the amount of stored body fat, typically achieved through a sustained caloric deficit combined with resistance training to help preserve muscle mass. Fat loss is distinct from simple weight loss, which can also include the loss of muscle or water. → Fat loss vs. weight loss: are you sure you’re losing fat?
- Fats
- A group of organic compounds including animal fats, such as butter and lard, and vegetable fats, such as vegetable and bean oils. Fats are a dense source of dietary energy and play essential roles in hormone production and overall body chemistry.
- Fiber
- An indigestible component of food, chemically classified as a carbohydrate, found mainly in unprocessed vegetables, nuts, grains, and fruits. Fiber provides no usable calories itself but offers significant digestive and overall health benefits as part of the diet. → Dietary fiber for athletes
- Fight-or-flight response
- The body’s automatic physiological reaction to a perceived threat or stressor, including intense exercise, triggered by hormones such as adrenaline and cortisol. The response increases heart rate, blood flow to muscles, and alertness, temporarily boosting physical performance. → Adrenaline & noradrenaline in exercise: fight-or-flight hormones
- Flexibility
- The suppleness of joints, muscle fibers, and connective tissue, which determines the available range of motion around a joint. Flexibility is an important component of overall fitness and is best developed through systematic, regular stretching. → Health benefits of improved flexibility
- Flexion
- The act of bending a joint — for example, the elbow flexes during a biceps curl. Flexion is the opposite of extension.
- Fluid retention
- A bodybuilding term referring to the amount of water held between the skin and the underlying muscle. A bodybuilder “holding water” appears smoother and softer, with reduced muscle definition and visible separation. → Water retention and anabolic steroids
- Forced reps
- An advanced training technique in which a training partner provides just enough assistance to help a lifter complete a few extra repetitions after their muscles have reached the point of fatigue under their own power.
- Form
- The use of proper biomechanics during an exercise, ensuring that only the intended muscle groups are doing the work and that every movement is performed safely to minimize the risk of injury.
- Free weights
- A general term for barbells and dumbbells, as opposed to machines that guide the weight along a fixed path. Free-weight exercises are among the most popular and effective tools used by bodybuilders, since they require greater stabilization and recruit more supporting muscle groups. → Free weights: the main tool for building muscles
- Frequency (training frequency)
- How often a given muscle group, or the body as a whole, is trained within a set period — usually expressed as sessions per week. Research generally supports training each muscle group at least twice per week for optimal growth, though optimal frequency varies with volume, recovery, and experience level. → Weight-training frequency: how many days a week should I work out?
- Full body workout
- A training structure in which most or all major muscle groups are trained within a single session, typically performed two to three times per week. Full body workouts are popular with beginners and with lifters who can only train a few days per week. → Barbell-only full body workout for beginners
