Figure Index
Every figure from every lecture, with its caption, in lecture order.
31 figures from 7 lectures.
Lecture 1: Basics in Exercise Physiology and Immunology - Key Concepts, Homeostasis and Hormesis
Homeostasis refers to the dynamic equilibrium of the internal environment, maintained through regulatory mechanisms that counteract disturbances. Physical activity is a significant disturbance to homeostasis, triggering rapid regulatory responses.
Homeostasis refers to the dynamic equilibrium of the internal environment, maintained through regulatory mechanisms that counteract disturbances. Physical activity is a significant disturbance to homeostasis, triggering rapid regulatory responses.
Example for acute disturbance of the homeostasis by acute physical stress. Heart rate and ventilation increase during exercise and return after the end of the exercise. Light blue lines: Physical rest before exercise, red lines: Incremental graded maximal cycle ergometer exercise, dark blue lines: physical rest after the end of exercise.
Example for acute disturbance of the homeostasis by acute physical stress. Heart rate and ventilation increase during exercise and return after the end of the exercise. Light blue lines: Physical rest before exercise, red lines: Incremental graded maximal cycle ergometer exercise, dark blue lines: physical rest after the end of exercise.
Homeostasis time-course: the IL-6 peak, delayed IL-10/IL-1Ra counter-response, functional capacity dip, and the set-point reference line, with annotated phase zones.
Homeostasis time-course: the IL-6 peak, delayed IL-10/IL-1Ra counter-response, functional capacity dip, and the set-point reference line, with annotated phase zones.
Hormesis dose-response: the full J-curve (URTI risk), bell-shaped adaptive benefit, and monotonically rising inflammatory load, with the three dose zones (sub-threshold / hormetic / overload) shaded.
Hormesis dose-response: the full J-curve (URTI risk), bell-shaped adaptive benefit, and monotonically rising inflammatory load, with the three dose zones (sub-threshold / hormetic / overload) shaded.
Lecture 2: Exercise and Immune System, Limits of Performance, Energy Balance
Limits of performance with age: relating MET, V̇O₂max, physical-activity behaviour and mortality/morbidity [%] across the lifespan — from physical inactivity (1 MET, 3.5 mL·min⁻¹·kg⁻¹) to very fast running (~26 METs, ~90 mL·min⁻¹·kg⁻¹) — demonstrates age-dependent changes in maximal performance capacity.
Limits of performance with age: relating MET, V̇O₂max, physical-activity behaviour and mortality/morbidity [%] across the lifespan — from physical inactivity (1 MET, 3.5 mL·min⁻¹·kg⁻¹) to very fast running (~26 METs, ~90 mL·min⁻¹·kg⁻¹) — demonstrates age-dependent changes in maximal performance capacity.
Adenosine-triphosphate (ATP) flow rates versus time. P — cycling performance on a bicycle ergometer; RPE — ratings of perceived exertion (Borg scale 6–20).
Adenosine-triphosphate (ATP) flow rates versus time. P — cycling performance on a bicycle ergometer; RPE — ratings of perceived exertion (Borg scale 6–20).
Time course of energy generation.
Time course of energy generation.
Cycle-ergometer exercise of different intensities and durations, showing performance, lactate generation and hormone secretion built up step by step. Male subjects with a V̇O₂max of 60–65 mL·min⁻¹·kg⁻¹.
Cycle-ergometer exercise of different intensities and durations, showing performance, lactate generation and hormone secretion built up step by step. Male subjects with a V̇O₂max of 60–65 mL·min⁻¹·kg⁻¹.
Overview of hormonal regulation and energy supply at different loads and load durations. RPE — rating of perceived exertion (Borg scale value).
Overview of hormonal regulation and energy supply at different loads and load durations. RPE — rating of perceived exertion (Borg scale value).
Lecture 3: Essential Components of the Immune System - Innate and Adaptive Immunity and the Chronological Immune Response to Viral Infections
Phases of the Immune Response -- Gantt-Style Timeline Chart. The innate immune response (black) is initiated within minutes; the adaptive response (dark grey) develops over days to weeks; immunological memory (medium grey, dotted) can persist lifelong. Onset dots mark the beginning of each phase. Adapted from Murphy K & Weaver C (2016). Janeway's Immunobiology, 9th edn.
Phases of the Immune Response -- Gantt-Style Timeline Chart. The innate immune response (black) is initiated within minutes; the adaptive response (dark grey) develops over days to weeks; immunological memory (medium grey, dotted) can persist lifelong. Onset dots mark the beginning of each phase. Adapted from Murphy K & Weaver C (2016). Janeway's Immunobiology, 9th edn.
Dendritic cells initiate adaptive immune responses. Immature dendritic cells in peripheral tissue take up pathogens via macropinocytosis and receptor-mediated endocytosis, then migrate to regional lymph nodes where they mature and activate naive T cells via antigen presentation and co-stimulatory molecules. Adapted from Murphy K & Weaver C (2016). Janeway's Immunobiology, 9th edn.
Dendritic cells initiate adaptive immune responses. Immature dendritic cells in peripheral tissue take up pathogens via macropinocytosis and receptor-mediated endocytosis, then migrate to regional lymph nodes where they mature and activate naive T cells via antigen presentation and co-stimulatory molecules. Adapted from Murphy K & Weaver C (2016). Janeway's Immunobiology, 9th edn.
NK cells are an early component of the host response to virus infection. IFN-α/IFN-β and cytokines (black, solid) are produced first, followed by NK-cell killing (dark grey, dashed); T-cell killing (medium grey, dotted) peaks later as the adaptive response matures. Virus titer (light grey, dash-dot) rises then falls once adaptive immunity is established. Adapted from Murphy K & Weaver C (2016). Janeway's Immunobiology, 9th edn.
NK cells are an early component of the host response to virus infection. IFN-α/IFN-β and cytokines (black, solid) are produced first, followed by NK-cell killing (dark grey, dashed); T-cell killing (medium grey, dotted) peaks later as the adaptive response matures. Virus titer (light grey, dash-dot) rises then falls once adaptive immunity is established. Adapted from Murphy K & Weaver C (2016). Janeway's Immunobiology, 9th edn.
Lecture 4: Teaching Anaerobic Threshold
Schematic representation of the aerobic–anaerobic transition (grey zone). Top: blood-lactate curve with aerobic threshold (AeS) and individual anaerobic threshold (IAS ≙ MLSS). Bottom: pulmonary ventilation with the two ventilatory thresholds VT1 and VT2 (RCP). Redrawn after Kindermann (2004).
Schematic representation of the aerobic–anaerobic transition (grey zone). Top: blood-lactate curve with aerobic threshold (AeS) and individual anaerobic threshold (IAS ≙ MLSS). Bottom: pulmonary ventilation with the two ventilatory thresholds VT1 and VT2 (RCP). Redrawn after Kindermann (2004).
Lactate–velocity curve during incremental exercise (red) and lactate–time curve during recovery (blue). The dashed grey line marks L_end. The descending recovery curve crosses L_end at ≈ 2.7 min post-exercise (linear interpolation between R1 = 10.0 mmol/L at 1 min and R2 = 8.8 mmol/L at 3 min → L = 9.0 at t ≈ 2.7 min): this is the anchor. The dashed green line is the tangent from the anchor to the ascending exercise curve; the tangent contact on the exercise curve is the IAT. Vertical and horizontal projections give v_IAT and L_IAT respectively.
Lactate–velocity curve during incremental exercise (red) and lactate–time curve during recovery (blue). The dashed grey line marks L_end. The descending recovery curve crosses L_end at ≈ 2.7 min post-exercise (linear interpolation between R1 = 10.0 mmol/L at 1 min and R2 = 8.8 mmol/L at 3 min → L = 9.0 at t ≈ 2.7 min): this is the anchor. The dashed green line is the tangent from the anchor to the ascending exercise curve; the tangent contact on the exercise curve is the IAT. Vertical and horizontal projections give v_IAT and L_IAT respectively.
Typical blood-lactate ranges encountered during the four endurance-training zones, expressed as a percentage of the individual anaerobic threshold (IAS). Redrawn after Kindermann (2004).
Typical blood-lactate ranges encountered during the four endurance-training zones, expressed as a percentage of the individual anaerobic threshold (IAS). Redrawn after Kindermann (2004).
Lecture 5: Estimation of VO₂max after Nes et al. (2011) – Worked Example
One-at-a-time sensitivity of the Nes et al. (2011) VO₂max estimate, shown against the ±1 SEE and ±1.96 SEE prediction bands.
One-at-a-time sensitivity of the Nes et al. (2011) VO₂max estimate, shown against the ±1 SEE and ±1.96 SEE prediction bands.
Male vs. female VO₂max equation applied to one identical input profile; bars and SEE bands in greyscale.
Male vs. female VO₂max equation applied to one identical input profile; bars and SEE bands in greyscale.
Person comparison of Example 2 (fit young female) and Example 3 (inactive older male), each with own profile and equation.
Person comparison of Example 2 (fit young female) and Example 3 (inactive older male), each with own profile and equation.
Lecture 6: Basics of Biochemistry Principles of Exercise
The three energy systems compared by the two properties that matter in practice: how fast they resynthesise ATP, and how long they can keep it up. ATP–PCr delivers the highest rate but is spent within 5–10 s, glycolysis peaks over 30–90 s, and oxidative phosphorylation sustains a moderate rate for effectively unlimited duration. Note the logarithmic time axis.
The three energy systems compared by the two properties that matter in practice: how fast they resynthesise ATP, and how long they can keep it up. ATP–PCr delivers the highest rate but is spent within 5–10 s, glycolysis peaks over 30–90 s, and oxidative phosphorylation sustains a moderate rate for effectively unlimited duration. Note the logarithmic time axis.
After uptake into the cell, glucose is phosphorylated and passes through glycolysis down to pyruvate. Under anaerobic conditions, pyruvate is converted to lactate to regenerate the NAD⁺ required for glycolysis, and lactate is typically released by the cells (2 mol ATP per mol glucose). Under aerobic conditions, pyruvate enters the mitochondria and is converted to acetyl-CoA by oxidative decarboxylation, feeding the citrate cycle; it is broken down to CO₂ and the reduction equivalents NADH/H⁺ and FADH₂, whose oxygen-dependent reoxidation yields water and is coupled to ATP synthesis from ADP and Pᵢ, giving ≈ 30 mol ATP per mol glucose.
After uptake into the cell, glucose is phosphorylated and passes through glycolysis down to pyruvate. Under anaerobic conditions, pyruvate is converted to lactate to regenerate the NAD⁺ required for glycolysis, and lactate is typically released by the cells (2 mol ATP per mol glucose). Under aerobic conditions, pyruvate enters the mitochondria and is converted to acetyl-CoA by oxidative decarboxylation, feeding the citrate cycle; it is broken down to CO₂ and the reduction equivalents NADH/H⁺ and FADH₂, whose oxygen-dependent reoxidation yields water and is coupled to ATP synthesis from ADP and Pᵢ, giving ≈ 30 mol ATP per mol glucose.
Left: ATP yield per mole of substrate on a logarithmic scale — 2 for anaerobic glycolysis, ~31 for the complete aerobic oxidation of glucose, and 106 for palmitate. Right: the direct consequence, the Pasteur effect. Because the anaerobic yield is roughly 15-fold lower, about 15× as much glucose must be consumed anaerobically to liberate the same amount of ATP (Nelson & Cox 2013).
Left: ATP yield per mole of substrate on a logarithmic scale — 2 for anaerobic glycolysis, ~31 for the complete aerobic oxidation of glucose, and 106 for palmitate. Right: the direct consequence, the Pasteur effect. Because the anaerobic yield is roughly 15-fold lower, about 15× as much glucose must be consumed anaerobically to liberate the same amount of ATP (Nelson & Cox 2013).
The crossover from fat to carbohydrate as exercise intensity rises. At low intensity the CHO:fat ratio is about 30:70, near 50:50 at moderate intensity, and 85:15 at high intensity. FAT_max — the intensity at which absolute fat oxidation peaks — lies at roughly 45–65 % V̇O₂max, well below the intensity at which carbohydrate begins to dominate the mixture.
The crossover from fat to carbohydrate as exercise intensity rises. At low intensity the CHO:fat ratio is about 30:70, near 50:50 at moderate intensity, and 85:15 at high intensity. FAT_max — the intensity at which absolute fat oxidation peaks — lies at roughly 45–65 % V̇O₂max, well below the intensity at which carbohydrate begins to dominate the mixture.
Lecture 7: Exercise Snacks
Summary of evidence-based effects on energy metabolism, muscular adaptations, aerobic capacity and immunological signalling pathways of Exercise Snacks (created in BioRender; Puta C, 2025).
Summary of evidence-based effects on energy metabolism, muscular adaptations, aerobic capacity and immunological signalling pathways of Exercise Snacks (created in BioRender; Puta C, 2025).
Left: blood glucose after a meal preceded by six one-minute exercise snacks versus a no-exercise control; the shaded area is the difference in glycaemic excursion. Right: the two summary effects — a ~1.4 mmol·L⁻¹ lower 3-hour postprandial peak after breakfast and a ~0.7 mmol·L⁻¹ lower 24-hour mean glucose, in insulin-resistant adults (Carter & Solomon 2020).
Left: blood glucose after a meal preceded by six one-minute exercise snacks versus a no-exercise control; the shaded area is the difference in glycaemic excursion. Right: the two summary effects — a ~1.4 mmol·L⁻¹ lower 3-hour postprandial peak after breakfast and a ~0.7 mmol·L⁻¹ lower 24-hour mean glucose, in insulin-resistant adults (Carter & Solomon 2020).
Reduction in mortality risk associated with vigorous intermittent lifestyle physical activity, by outcome. Three separate bouts of 1–2 min per day are associated with larger reductions than a single daily bout of 4.4 min, and the effect is largest for cardiovascular mortality. UK Biobank, n = 25,241 non-exercisers, mean age 61.8 y (Stamatakis et al. 2022).
Reduction in mortality risk associated with vigorous intermittent lifestyle physical activity, by outcome. Three separate bouts of 1–2 min per day are associated with larger reductions than a single daily bout of 4.4 min, and the effect is largest for cardiovascular mortality. UK Biobank, n = 25,241 non-exercisers, mean age 61.8 y (Stamatakis et al. 2022).
Exercise Snack protocols and anti-inflammatory efficacy (data: literature analysis). HIIT: high-intensity interval training.
Exercise Snack protocols and anti-inflammatory efficacy (data: literature analysis). HIIT: high-intensity interval training.
Exercise Snacks — energy-metabolism signalling. Both the GLUT4 and LPL axes operate insulin-independently via AMPK, converging on reduced insulin resistance and lower cardiovascular risk.
Exercise Snacks — energy-metabolism signalling. Both the GLUT4 and LPL axes operate insulin-independently via AMPK, converging on reduced insulin resistance and lower cardiovascular risk.
Exercise Snacks — muscle signalling: three staggered phases from acute AMPK/PGC-1α through mTORC1-driven protein synthesis to satellite-cell hypertrophy.
Exercise Snacks — muscle signalling: three staggered phases from acute AMPK/PGC-1α through mTORC1-driven protein synthesis to satellite-cell hypertrophy.
Exercise Snacks — aerobic-capacity signalling: central (CO) and peripheral (a-vO₂ diff) adaptations framed by the Fick equation, with snacks disproportionately targeting the peripheral side.
Exercise Snacks — aerobic-capacity signalling: central (CO) and peripheral (a-vO₂ diff) adaptations framed by the Fick equation, with snacks disproportionately targeting the peripheral side.
Exercise Snacks — immunological signalling: three parallel axes (myokines, transcriptional reprogramming, microbiome metabolites) converging on NF-κB suppression.
Exercise Snacks — immunological signalling: three parallel axes (myokines, transcriptional reprogramming, microbiome metabolites) converging on NF-κB suppression.
The four domains on a shared logarithmic time axis, from the stimulus to the adaptation. Energy metabolism responds within minutes to hours, immune signalling over hours to weeks, muscle structure over hours to months, and aerobic capacity only after weeks — which is why a single snack is measurable in glucose but not in V̇O₂max. Central mediators are named below each bar.
The four domains on a shared logarithmic time axis, from the stimulus to the adaptation. Energy metabolism responds within minutes to hours, immune signalling over hours to weeks, muscle structure over hours to months, and aerobic capacity only after weeks — which is why a single snack is measurable in glucose but not in V̇O₂max. Central mediators are named below each bar.