Plain-English definitions of the terms that come up across strength training, muscle building, mobility, and body composition — so you actually understand what each session is doing for your body, and why the way it is programmed matters.
Also known as: 1-2-1 PT, In-person coaching.
One-to-one coaching delivered in person, where the coach designs and supervises every session in real time. The coach watches your movement, adjusts load and intensity to the day, and gives immediate feedback. It is the highest-touch coaching format — and the right one when technique, accountability, and steady progress all matter.
A personalised training and nutrition programme delivered remotely through an app or shared plan, with regular check-ins by message or video. Suits people who already train with some confidence and want intelligent programming and accountability without booking in-person session time.
Also known as: Resistance training, Weight training.
Training that uses resistance — barbells, dumbbells, machines, or bodyweight — to build the force your muscles can produce. The foundation strength sits under almost every other goal: more usable strength makes building muscle, moving well, and staying capable with age all easier.
Source: en.wikipedia.org
The gradual, deliberate increase in the demand placed on the body over time — through load, reps, sets, range, or tempo — to drive continued adaptation. It is the single most important principle in strength and muscle work, but only effective when paired with enough recovery between sessions.
Source: en.wikipedia.org
Also known as: Muscle growth.
The growth of muscle tissue in response to resistance training. Driven by mechanical tension, sufficient training volume, and adequate protein and recovery. Most muscle-building programmes are built around hypertrophy principles; gaining quality muscle is a patient process measured over months, not weeks.
Source: en.wikipedia.org
Also known as: Joint mobility.
Active control over a joint’s available range of motion — combining the flexibility to reach a position with the strength to own and move within it. Different from flexibility alone: a mobile joint is both supple and controllable. Targeted mobility work is a defining part of how Jasper programmes training.
Source: www.nhs.uk
Also known as: FRC.
A joint-by-joint mobility and strength system that develops controlled, usable range of motion through specific isometric and end-range training. Created by Dr Andreo Spina, it is the framework behind much of how Jasper trains mobility — making range something you control under load, not just stretch into.
Source: functionalanatomyseminars.com
Also known as: ROM.
The measurable degree to which a joint can move in a given direction. Reduced range is often an early sign of stiffness or restriction; restoring and then controlling range is one of the most-tracked outcomes of mobility-focused strength work, and one of the first things training in your 40s should address.
Source: en.wikipedia.org
Also known as: Multi-joint exercise, Big lifts.
A multi-joint exercise that recruits several large muscle groups at once — the squat, deadlift, bench press, overhead press, and row are the classic examples. Compound lifts deliver the most training stimulus per unit of time and form the backbone of most well-built strength and muscle programmes.
Source: en.wikipedia.org
Smaller, more isolated exercises that support the main compound lifts by addressing weak points, asymmetries, or muscle groups the big lifts under-stimulate. Examples include split squats, single-arm rows, and rear-delt raises. Accessory work is where most imbalances quietly get resolved over time.
Also known as: Periodization, Phase-based training.
The planned organisation of training into phases with different focus and intensity across weeks or months. It lets training progress, peak, and recover deliberately — training in blocks (build → develop → consolidate) rather than chasing the same hard workout every session, which is how progress stays varied for years.
Source: en.wikipedia.org
Also known as: RPE.
A 1–10 self-reported scale describing how hard a set felt: RPE 10 means no further reps were possible; RPE 7 means roughly three reps were left in the tank. It lets a coach prescribe intensity that auto-regulates to how your body actually performs on the day, not how it performed last week.
Source: en.wikipedia.org
The relative proportions of fat mass, lean tissue, bone, and water in the body — a far more meaningful health and performance marker than scale weight alone. Two people at the same weight can carry very different proportions of muscle and fat. It is best tracked over weeks rather than day to day.
Source: en.wikipedia.org
Also known as: Body recomposition.
Reducing body-fat mass while preserving as much muscle as possible — best achieved through a modest, sustainable energy deficit alongside strength training and enough protein. It differs from simple weight loss, which can strip muscle too; the goal is to change how the body is composed, not just what it weighs.
Source: www.nhs.uk
A macronutrient made of amino acids that the body uses to repair and build tissue, including muscle. Adequate daily protein is one of the biggest levers for building or keeping muscle and for managing appetite during fat loss — which is why nutrition guidance sits alongside the training, not after it.
Source: en.wikipedia.org
The dull, diffuse muscle ache that peaks 24–72 hours after unfamiliar or hard exercise, caused by micro-damage and repair. Mild DOMS is a normal training response and not a measure of a good session; persistent or severe DOMS suggests load, volume, or recovery is mismatched to your current capacity.
Source: en.wikipedia.org
The processes — sleep, tissue repair, refuelling, and stress management — that let the body adapt to the last training stimulus. Recovery is where the adaptation actually happens, so it is not optional. Sleep quality, nutrition, stress load, and sensible training volume are the inputs that decide how much progress you keep.
Source: www.nhs.uk
Also known as: Maximal oxygen uptake, Aerobic capacity.
The maximum rate at which the body can take in, transport, and use oxygen during intense exercise. It is one of the strongest predictors of cardiovascular health and long-term capacity, and it can be improved at any age with structured training — which is why conditioning has a place even in a strength-led plan.
Source: en.wikipedia.org