FSHP Academy

Visual library

Diagram library

25 original diagrams. Each is drawn as accessible SVG with a text description and adapts to light and dark themes.

The three cardinal planes of motion and their axes Three panels each show a standing figure. Left: the sagittal plane divides the body into left and right halves; movement in it rotates about a mediolateral axis (flexion and extension). Middle: the frontal plane divides front from back; movement rotates about an anteroposterior axis (abduction and adduction). Right: the transverse plane divides upper from lower; movement rotates about a vertical axis (rotation). Sagittal plane Mediolateral axis Flexion · extension e.g. Squat, curl, walking stride Frontal (coronal) plane Anteroposterior axis Abduction · adduction · lateral flexion e.g. Lateral raise, side lunge, jumping jack Transverse plane Longitudinal (vertical) axis Internal/external rotation · trunk rotation e.g. Woodchop, golf swing, pivot Dashed line = axis of rotation (always perpendicular to its plane)
Planes Axes — used in: Anatomical terminology, planes, axes and movement directions
Sarcomere structure, relaxed and contracted Two sarcomeres are drawn between Z-discs. Thin actin filaments attach to each Z-disc and point toward the centre; thick myosin filaments sit in the middle, anchored at the M-line, with cross-bridge heads. In the contracted sarcomere the Z-discs are closer together, the actin filaments slide further over the myosin, the I-band and H-zone shorten, while the A-band (length of myosin) stays the same. Relaxed (longer sarcomere) A-band = myosin length (260 units — unchanged) ½ I-band H-zone Z-disc Z-disc Contracted (shorter sarcomere) A-band = myosin length (260 units — unchanged) ½ I-band H-zone Z-disc Z-disc Actin (thin) Myosin (thick) M-line = dashed centre line. Filaments do not shorten — they slide.
Sarcomere — used in: Muscle physiology: excitation–contraction and the sliding filament model
Force–velocity relationship of skeletal muscle A graph of muscle force against shortening velocity. At zero velocity (isometric) force equals maximal isometric force. To the right, concentric force falls in a curved fashion as shortening speed increases, reaching zero at maximal velocity. To the left, during eccentric (lengthening) actions, force rises above isometric maximum and plateaus. F₀ = maximal isometric force Isometric (v = 0) ECCENTRIC muscle lengthens under load force can exceed F₀ CONCENTRIC muscle shortens faster = less force v_max ← lengthening velocity · 0 · shortening velocity → Force (relative to F₀) 00.511.5
Force Velocity — used in: Concentric, eccentric and isometric muscle actions
Relative contribution of energy systems by duration of maximal effort A stacked area chart with exercise duration on a logarithmic axis from 1 second to 5 minutes. The phosphagen (ATP-PC) system dominates the first few seconds, glycolysis contributes most between roughly 10 and 60 seconds, and the aerobic system becomes the majority contributor from about 75 seconds onward. All three systems contribute at every time point. ~75 s: aerobic ≈ 50 % ATP-PC Glycolytic Oxidative (aerobic) 1 s3 s10 s30 s1 min2 min5 min 0%25%50%75%100% Duration of maximal effort (log scale) Share of ATP resynthesis
Energy Systems — used in: Energy systems overview: how the body makes ATP
Determinants of cardiac output and oxygen uptake Flow diagram. Heart rate is set by autonomic nervous system balance. Stroke volume is set by preload (end-diastolic volume), contractility and afterload. Heart rate multiplied by stroke volume gives cardiac output. Cardiac output multiplied by the arteriovenous oxygen difference gives oxygen uptake, which is the Fick equation. Autonomic balance sympathetic ↑ · vagal ↓ Preload (EDV, venous return) Contractility Afterload (arterial pressure) Heart rate (HR) beats · min⁻¹ Stroke volume (SV) mL · beat⁻¹ (↑ afterload ↓ SV) × Cardiac output (Q̇) L · min⁻¹ = HR × SV a–v̄O₂ difference O₂ extracted by tissues Oxygen uptake (V̇O₂) V̇O₂ = Q̇ × (a–v̄O₂ diff) Fick principle: oxygen uptake = delivery (Q̇) × extraction (a–v̄O₂ difference)
Cardiac Output — used in: Stroke volume, heart rate and cardiac output
VO₂ max plateau and the oxygen transport chain Left: a graph of oxygen uptake against increasing work rate. Oxygen uptake rises roughly linearly and then levels off; the plateau is VO₂ max. Right: the oxygen cascade from lungs to blood to heart to working muscle; in healthy people exercising with a large muscle mass at sea level, maximal cardiac output is the main limiting step. Plateau = V̇O₂max linear rise with work rate 0204060 Work rate (incremental test) → V̇O₂ (mL·kg⁻¹·min⁻¹) Illustrative data for a recreationally trained adult. The oxygen cascade Lungs ventilation, diffusion Blood haemoglobin, O₂ content Heart max cardiac output Muscle capillaries, mitochondria Thick border = main limiting step in healthy, whole-body exercise at sea level
V O2 Plateau — used in: VO₂ max
Exercise intensity categories by heart rate and perceived exertion A horizontal scale of percentage of maximal heart rate from 45 to 100 percent. Bands show ACSM intensity categories: very light below 57 percent, light 57 to 63, moderate 64 to 76, vigorous 77 to 95, near maximal 96 and above, with matching Borg RPE ranges. Underneath, a three-zone physiological model is shown: zone 1 below the first lactate or ventilatory threshold, zone 2 between thresholds, and zone 3 above the second threshold. Threshold positions vary between individuals. ACSM category Borg RPE (6–20) Very light < 9 Light 9–11 Moderate 12–13 Vigorous 14–17 Near max ≥ 18 50%57%64%77%90%96%100% % HRmax 3-zone model Zone 1 · below LT1/VT1 Zone 2 Zone 3 · above LT2 LT1 / VT1 LT2 / VT2 Top: ACSM (Garber et al., 2011). Bottom: three-zone model (Seiler, 2010); threshold positions shown are typical of trained endurance athletes and vary widely between people — only a lab or field threshold test locates them for an individual.
Intensity Zones — used in: Heart rate zones and RPE-based intensity control · Aerobic endurance training
Structure of a long bone A long bone shown in longitudinal section. The shaft (diaphysis) has a thick outer wall of compact bone around a central medullary cavity containing yellow marrow. Each enlarged end (epiphysis) is filled with spongy (trabecular) bone containing red marrow and is capped with articular cartilage. An epiphyseal line marks the former growth plate. The periosteum covers the outer surface except at the joint surfaces. Proximal epiphysis Diaphysis (shaft) Distal epiphysis Periosteum Compact (cortical) bone Medullary cavity (yellow marrow) Spongy bone (red marrow) Articular cartilage Epiphyseal line Cells: osteoblasts build bone · osteoclasts resorb bone ·osteocytes (embedded in bone) sense mechanical strain and direct remodelling.
Long Bone — used in: Bone structure, remodelling and adaptation to loading
Synovial joint structure and the six types of synovial joint Left: a synovial joint in section. Two bone ends are covered with articular cartilage and enclosed by a fibrous joint capsule lined by synovial membrane; the joint cavity contains synovial fluid, and a ligament reinforces the capsule. Right: a table of the six synovial joint types with their degrees of freedom and examples. Bone Articularcartilage Synovial fluid in cavity Fibrouscapsule Synovialmembrane Ligament Six synovial joint types Hinge 1 DOF Elbow (humero-ulnar), knee*, ankle Pivot 1 DOF Atlanto-axial, proximal radio-ulnar Condyloid 2 DOF Wrist (radiocarpal), MCP joints Saddle 2 DOF Thumb carpometacarpal Ball & socket 3 DOF Hip, glenohumeral Plane (gliding) small glides Intercarpal, facet joints DOF = degrees of freedom. *Knee: modified hinge; rotates when flexed.
Synovial Joint — used in: Joint types and classification
Muscle architecture: parallel, unipennate and bipennate Three muscles of equal volume. In the parallel muscle, long fibres run along the line of pull, favouring shortening speed and range. In the unipennate muscle, shorter fibres attach at an angle to one side of a central tendon. In the bipennate muscle, fibres attach to both sides of a central tendon. Pennation packs more fibres side by side, increasing physiological cross-sectional area and force, at the cost of fibre length and shortening velocity. Parallel (fusiform) Long fibres · high velocity & range e.g. biceps brachii, sartorius θ Unipennate Angled fibres · more PCSA e.g. vastus lateralis (regionally) Bipennate Most fibres packed · high force e.g. rectus femoris θ = pennation angle; tendon in dark grey
Muscle Architecture — used in: Muscle architecture: pennation, length and cross-sectional area
The size principle of motor unit recruitment Horizontal bars represent eleven motor units ordered from small to large. Each bar begins at the force level at which that unit is recruited and continues to maximal force. Small, low-threshold units are recruited at low forces; progressively larger units are added as force increases. Bar thickness grows with unit size. Beyond the last recruitment threshold, further force comes from increased firing rates (rate coding). rate coding only 0%20%40%60%80%100% Force (% of maximal voluntary contraction) Small unitsmostly type Ifatigue-resistant Large unitsmostly type IIhigh force, fatigable Illustrative. Upper recruitment limit varies by muscle: ~50 % MVC in small hand muscles, up to ~85–90 % in large limb muscles.
Size Principle — used in: Motor units, recruitment and rate coding
Three classes of lever in the body Three beams. First class: the fulcrum lies between the effort and the load. Second class: the load lies between the fulcrum and the effort. Third class: the effort lies between the fulcrum and the load, which is the most common arrangement in the human body and favours speed and range of motion over force. Torque equals force multiplied by its perpendicular moment arm. First class E · F · L F L E Head on the atlanto-occipital joint:neck extensors balance the head MA can be >1, =1 or <1 Second class F · L · E F L E Often taught: heel raise (toes = fulcrum).Its classification is debated. MA > 1 — force advantage Third class F · E · L F L E Elbow flexion: biceps inserts near theelbow; load is held in the hand MA < 1 — speed & range advantage F = fulcrum (joint axis) · E = effort (muscle force) · L = loadMA = mechanical advantage = effort arm ÷ load arm · Torque = force × perpendicular moment arm
Lever Classes — used in: Levers, torque and moment arms
Blood lactate response to incremental exercise Blood lactate stays close to resting values (about 1 millimole per litre) at low running speeds, begins to rise at the first lactate threshold (LT1), and rises steeply beyond the second threshold (LT2, close to maximal lactate steady state). A fixed 4 millimole line is shown for comparison; it does not represent the same intensity for every athlete. fixed 4 mmol·L⁻¹ (“OBLA”) LT1 LT2 ≈ MLSS Moderate domain Heavy domain Severe domain 8101214161820 0246810 Running speed (km·h⁻¹) — illustrative trained runner Blood lactate (mmol·L⁻¹)
Lactate Curve — used in: Lactate threshold
Oxyhaemoglobin dissociation curve and the Bohr shift An S-shaped curve of haemoglobin oxygen saturation against partial pressure of oxygen. At lung levels near 100 mmHg, haemoglobin is about 97 percent saturated; in exercising muscle with low oxygen pressure, saturation falls steeply so oxygen is released. During exercise, higher temperature, more carbon dioxide, lower pH and more 2,3-BPG shift the curve to the right, releasing more oxygen at the same pressure. exercising muscle lungs extra O₂ released P50 ≈ 27 020406080100 0%25%50%75%100% Partial pressure of oxygen, PO₂ (mmHg) Hb saturation (SO₂) Rest Right shift: ↑ temperature↑ CO₂, ↓ pH↑ 2,3-BPG
Oxy Hb Curve — used in: Blood components and oxygen transport
Regions and curves of the vertebral column A side view of the spine with the front of the body on the left. Seven cervical vertebrae form a forward-convex curve (lordosis); twelve thoracic vertebrae form a backward-convex curve (kyphosis); five lumbar vertebrae form a forward-convex lordosis; below them the sacrum (five fused vertebrae) and coccyx curve backward. Vertebral bodies become larger from top to bottom as they carry more load. ← Anterior Posterior → Cervical (C1–C7) lordosis — convex anteriorly Thoracic (T1–T12) kyphosis — convex posteriorly Lumbar (L1–L5) lordosis — convex anteriorly Sacrum (5 fused) & coccyx kyphotic curve Vertebral bodies enlarge downward, matching load
Spine Curves — used in: Spine and posture
Preparticipation health screening logic (ACSM 2015) A grid. Columns separate people who do not currently exercise regularly from those who do. Rows separate people with no known cardiovascular, metabolic or renal disease and no symptoms; people with known disease but no symptoms; and people with signs or symptoms. Recommendations range from no medical clearance needed, to clearance recommended before vigorous exercise, to stopping exercise and seeking clearance. Not exercising regularly Exercising regularly ≥30 min, moderate, 3 d/wk, last 3 months

No known CV, metabolic or renal disease, no signs/symptoms

No medical clearance needed. Start light–moderate; progress gradually.

No medical clearance needed. Continue moderate or vigorous; progress gradually.

Known CV, metabolic or renal disease, no signs/symptoms

Medical clearance recommended. Then start light–moderate; progress gradually.

Clearance not needed for moderate; continue. Clearance recommended before vigorous.

Any signs or symptoms suggestive of CV, metabolic or renal disease

Medical clearance recommended before starting.

Stop exercise; seek medical clearance before resuming.

 CV = cardiovascular. Simplified from Riebe et al. (2015). Clinical judgement and local regulations still apply.
Screening Flow — used in: Preparticipation health screening
Force–time curves and rate of force development Two force–time curves reach the same peak force of about 2,800 newtons, but athlete A rises much faster than athlete B. Shaded windows mark typical ground-contact time in maximal sprinting (about 0.1 seconds) and in jumping (roughly 0.2 to 0.3 seconds). Within these short windows athlete A produces far more force, showing why rate of force development can matter more than peak force for fast movements. sprint contact jump take-off same peak force Athlete A — high RFD Athlete B — low RFD force gap at 100 ms 0100200300400500600 0100020003000 Time from onset (ms) · RFD = Δforce ÷ Δtime Force (N)
Force Time — used in: Force, rate of force development and the stretch-shortening cycle
The cardiac cycle: pressures and volume in the left ventricle Top panel: left-ventricular pressure rises during isovolumetric contraction until it exceeds aortic pressure, the aortic valve opens and blood is ejected; pressure then falls during isovolumetric relaxation and the ventricle refills at low pressure. Bottom panel: left-ventricular volume stays constant at about 120 millilitres during isovolumetric contraction, falls to about 50 millilitres during ejection, stays constant during isovolumetric relaxation and then rises during filling. Stroke volume is the difference, about 70 millilitres. Atrial systoleIVCEjectionIVRVentricular filling Aortic pressure LV pressure LV volume EDV ≈ 120 mL ESV ≈ 50 mL aortic valve opens closes 04080120 5085120 Pressure (mmHg) Volume (mL) One beat ≈ 0.8 s at 75 bpm · IVC/IVR = isovolumetric contraction/relaxation
Cardiac Cycle — used in: Heart anatomy and the cardiac cycle
Structure of a periodised annual plan A one-year macrocycle is divided into general preparation, specific preparation, pre-competition, competition and transition phases. Above, training volume starts high and falls as the season approaches, while intensity rises; both drop in the transition phase. Each phase is built from mesocycles of roughly two to six weeks, and each mesocycle from microcycles, usually one week, shown with an example sequence of sessions. Macrocycle (e.g., one year) VolumeIntensity General preparationSpecific preparationPre-comp.CompetitionTransition Mesocycles (≈2–6 weeks each) — highlighted block expanded below Mon Strength Tue Speed Wed Recovery Thu Power Fri Conditioning Sat Match/sim. Sun Off Microcycle (≈1 week): example in-season sequence. Real plans vary by sport, athlete and fixture schedule. Trend lines are schematic, not prescriptions.
Periodisation — used in: Periodisation cycles for functional training · Periodisation and long-term athlete development (LTAD)
Fitness–fatigue model of training response Top panel: each day of training adds to fitness, which builds and decays slowly, and to fatigue, which builds and decays quickly. Bottom panel: performance, modelled as fitness minus fatigue, stays suppressed during seven weeks of hard training; in the final ten-day taper, loads fall, fatigue clears faster than fitness, and performance rises to its highest level. Taper Responses to training Fitness — slow to build, slow to fade Fatigue — fast to build, fast to fade Performance = fitness − fatigue Bars: daily training load (one rest day per week). Days 0–60. Schematic Banister model; time constants (42 and 7 days) and weights are illustrative, not individual predictions.
Fitness Fatigue — used in: Deloading and fatigue management
Components of total daily energy expenditure Two horizontal stacked bars compare total daily energy expenditure. Both people have the same resting metabolic rate of about 1,600 kilocalories. The thermic effect of food adds roughly 10 percent of intake. The office worker has no planned exercise and low non-exercise activity, totalling about 2,100 kilocalories. The active person adds about 400 kilocalories of exercise and 700 of non-exercise activity, totalling about 2,980. Non-exercise activity is the most variable component. Office worker, little activity 1600300 ≈ 2110 kcal Active job + 45 min training 1600400700 ≈ 2980 kcal BMR / RMRTEF (~10%)Exercise (EAT)NEAT (most variable) Illustrative values for adults of similar body size. NEAT = non-exercise activity thermogenesis; TEF = thermic effect of food.
Energy Balance — used in: Calorie balance and metabolism
Protein intake and resistance-training gains in lean mass A schematic line shows additional gains in fat-free mass with resistance training rising as daily protein intake increases, then levelling off at about 1.6 grams per kilogram of body mass per day. A shaded band from about 1.0 to 2.2 grams per kilogram shows the uncertainty around this breakpoint; the upper value is a sensible target for those wanting to maximise gains. 95% CI of breakpoint ≈ 1.0–2.2 ~1.6 g·kg⁻¹·day⁻¹ RDA 0.8 00.511.522.53 Total daily protein intake (g per kg body mass) Extra fat-free mass gain Schematic of the meta-regression breakpoint in Morton et al. (2018); not individual-level data.
Protein Dose — used in: Balancing muscle gain and fat loss
The COM-B model of behaviour Behaviour results from three interacting sources: capability (physical and psychological), opportunity (physical and social) and motivation (reflective and automatic). Capability and opportunity influence motivation, all three influence behaviour, and behaviour in turn feeds back to change capability, opportunity and motivation. Capability Physical: skills, strengthPsychological: knowledge, planning Opportunity Physical: time, access, costSocial: norms, support Motivation Reflective: goals, beliefsAutomatic: habits, emotions Behaviour behaviour feeds back Michie et al. (2011)
C O M B — used in: Basics of behaviour change
Fundamental movement patterns Eight cards list fundamental movement patterns with their dominant joints and example exercises: squat, hinge, lunge or single-leg, push, pull, carry, rotate or anti-rotate, and locomotion or level change. Lower-body patterns are blue, upper-body patterns red, carries green, rotation amber and locomotion violet. Squat Knee + hip • Goblet squat• back squat• front squat Hinge Hip-dominant • RDL• deadlift• swing Lunge / single-leg Unilateral knee + hip • Split squat• step-up Push Horizontal / vertical • Push-up• bench• overhead press Pull Horizontal / vertical • Row• pull-up• lat pulldown Carry / gait Whole body, trunk stiffness • Farmer• suitcase• sled Rotate / anti-rotate Trunk, transverse plane • Woodchop• Pallof press Locomotion Gait, level changes • Crawl• get-up• sprint
Movement Patterns — used in: Fundamental movement patterns: push, pull, squat, hinge
The load–repetition continuum A curve shows the approximate percentage of one-repetition maximum that can be lifted for a given number of repetitions to failure, from 100 percent for one rep to about 50 percent for thirty reps. Maximal-strength gains are greatest with heavy loads of roughly one to six repetitions. Muscle growth is similar across a wide range of about six to thirty repetitions when sets are taken close to failure. Higher repetitions build local muscular endurance. Max strength Hypertrophy similar across this range if sets end close to failure (Schoenfeld et al., 2017) Muscular endurance emphasis 151015202530 40%60%80%100% Repetitions to failure Load (% of 1RM) Curve from the Epley equation; real values vary by exercise and individual. Zones overlap — they are emphases, not boundaries.
Load Continuum — used in: Progressive overload and programming variables (sets, reps, tempo)