GLP-1 & Strength Glossary

28 terms, defined plainly. Several of these entries exist because the term is routinely misused — and the misuse changes what you’d conclude about your own body.

Associated with: A phrase meaning two things were observed together — not that one caused the other.; This site uses it deliberately and often. Most nutrition and exercise findings are associations, and describing them as causes would overstate what the research shows.
Bioelectrical impedance (BIA): The method behind body-fat scales: a small current is passed through you and body composition is estimated from the resistance.; Official guidance validates it in people without significant fluid and electrolyte abnormalities — so readings assume normal hydration. It is typically reliable (repeatable) without being accurate: one research-grade device was off by about four percentage points of body fat against a reference scan.; Read more
BMI (body mass index): Your weight in kilograms divided by your height in metres squared — a population screening measure, not an individual diagnosis.; The CDC states plainly that BMI does not distinguish between fat, muscle and bone mass. Two people at the same BMI can carry very different amounts of muscle, and building muscle pushes BMI up exactly as fat would.; Read more
Body composition: The split of your body weight into fat mass and everything else, rather than one combined number on a scale.; It answers the question a scale cannot: whether the weight you lost was fat or the muscle you were trying to keep.; Read more Read more
Bone mineral density (BMD): A measure of how much mineral is packed into your bone, usually reported from a DEXA scan.; Substantial weight loss by any method is associated with some reduction in bone density, which is why loading your bones and covering calcium, vitamin D and protein matter more while losing weight.; Read more
Calorie deficit: Taking in less energy than you use, which is what drives weight loss.; On a GLP-1 the deficit largely happens by itself through reduced appetite — which is why the useful question shifts from "how do I eat less" to "how do I protect muscle while eating less".; Read more
Creatine: A compound stored in muscle and found mostly in meat, and the most-studied training supplement.; The evidence is specifically about creatine combined with resistance training; researchers note it is minimally effective without the training. Any question about whether it suits you is one for a healthcare provider.; Read more
DEXA / DXA scan: A low-dose X-ray scan that separates your body into fat mass, lean soft tissue and bone — the reference method for body composition in clinical practice.; Accurate, but not exact. Repeat scans on consecutive days have differed by around 2 kg of lean mass from measurement variation alone, and machines from different manufacturers are not interchangeable.; Read more
Electrolytes: Minerals — chiefly sodium, potassium and magnesium — that travel in your body fluids.; They matter on a GLP-1 because eating and drinking less, plus the medication’s digestive effects, can mean losing fluids and the electrolytes in them. Replacing what you lose is the point; they are not an energy source.; Read more
Form score: A rating of how well a repetition was performed, based on joint positions and movement path.; On this site it is the progress signal that needs no scan and no scale — unlike a body-composition estimate, it has no meaningful measurement error.; Read more
Full-body workout: A session that trains the major muscle groups together — legs, a push, a pull and the middle — rather than splitting them across days.; It suits a two-or-three-day week because every muscle gets trained at least twice, and missing one session does not leave half of you untrained.; Read more
Gastric emptying: How quickly food leaves your stomach.; GLP-1 medications slow gastric emptying and small-intestine motility, which is why a few bites can feel like a full meal. Reviewers note the slowing effect tends to become less pronounced over longer treatment.; Read more
GLP-1: Glucagon-like peptide-1 — a hormone your gut releases after eating, and the name given to a class of medications that mimic it.; These medications slow how quickly the stomach empties and reduce appetite, which is why people on them eat considerably less. That is also why protein and training take deliberate effort rather than happening by default.; Read more Read more
Lean body mass: Everything in your body that is not fat: water, protein, minerals, bone and organs.; Lean mass is not a synonym for muscle, and treating it as one is the most common mistake in this subject. Fat-free mass is roughly 74% water, and researchers estimate only around 60% of the fat-free mass lost during weight loss comes from skeletal muscle. So a lean-mass drop is an upper bound on muscle loss, not a measurement of it.; Read more Read more
Loose skin: Skin that no longer sits tightly against the body after substantial weight loss.; Training changes the muscle underneath and therefore your shape; it does not change the skin itself. Anything cosmetic is a conversation for a dermatologist or clinician.; Read more
Measurement error: The amount a reading can differ from one attempt to the next without anything having actually changed.; Every measure on this site has one: around 2 kg of lean mass between DEXA scans a day apart, several percentage points for body-fat estimates, and 1.4 to 15 cm for waist measurements taken by different people.; Read more
Meta-analysis: A study that statistically pools results from multiple separate studies to produce a combined estimate.; Usually stronger evidence than any single trial, but only as good as the studies inside it — and a pooled average can hide wide variation between them.
Muscle protein synthesis: The process of building new muscle protein, which rises after resistance training and after eating protein.; It is a mechanism, not a promise — it explains why training and protein work together rather than guaranteeing any particular result.; Read more
Progressive overload: Gradually asking a little more of your body over time — an extra rep, slightly more resistance, or another set.; Without it, training stops producing change. On a GLP-1 progress is often slower because you are eating less, and holding your numbers steady while body weight falls is itself a good result.; Read more
Protein target: A daily amount of protein, usually expressed in grams per kilogram of body weight.; Two credible bands answer different questions: an expert consensus for the GLP-1 weight-loss phase suggests 1.2–1.5 g per kg of body weight, while the International Society of Sports Nutrition puts 1.4–2.0 g per kg for most exercising people.; Read more
Randomised controlled trial (RCT): A study where participants are randomly assigned to groups, which is what allows a comparison to support cause rather than just association.; Worth distinguishing from a review or a commentary, which summarise or argue about existing evidence rather than generating new data.
Rate of weight loss: How fast weight comes off, usually expressed as a percentage of body weight per week.; Larger and faster loss is associated with greater loss of lean mass and bone density. Clinical guidance has long described roughly 1–2 lb a week as a sensible pace.; Read more Read more
Reliable vs accurate: Reliable means a measurement repeats consistently; accurate means it is close to the truth. A tool can be one without the other.; This distinction decides how to use every measuring device on this site. A body-fat scale that is consistently wrong in the same direction is useless for its absolute number and still useful for a trend.; Read more
Resistance training: Exercise where your muscles work against a load — body weight, bands, dumbbells or machines.; It is the signal that tells your body to hold onto muscle while you lose weight. Public-health guidance recommends muscle-strengthening activity covering all major muscle groups on two or more days a week.; Read more Read more
Skeletal muscle: The muscle attached to your skeleton that moves you — one component inside lean body mass, not the whole of it.; Formal methodological guidance is explicit that skeletal muscle sits at a different level of description from fat-free mass, and that the terms should not be used interchangeably.; Read more Read more
Waist-to-height ratio: Your waist measurement divided by your height, in the same units — a simple marker of central adiposity.; NICE guidance suggests keeping your waist to less than half your height, and states the classification can be used for adults of both sexes and all ethnicities with a BMI under 35, including adults with high muscle mass — the group BMI most often misclassifies.; Read more
Weight regain: Weight returning after a period of loss, commonly reported after stopping weight-loss medication.; This site treats it as a reason to build training and eating habits early, not as a prediction about any individual.; Read more
Weight-bearing exercise: Movement where you support your own body weight against gravity — walking, stairs, standing up from a chair.; Distinct from resistance training, and distinct again from swimming or cycling, which are good for you but do not load bone in the same way.; Read more

The term worth remembering is the first one people get wrong: lean mass is not muscle. Mira measures the thing that actually is — what you can lift, session after session, with your form scored through your phone.

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