# PWR-023 — Metabolic flexibility: learner worksheet Release: Revision 7T · Full Tutorial Edition Estimated time: Estimated 28 min reading and worksheet pass Difficulty: Intermediate Equipment: Basic stationery or digital tools — The full primary paper, protocol and supplementary methods; A data-extraction sheet with stimulus, timing, diet/fasting, prior exercise, gas system and population; A calculator or spreadsheet for supplied RER differences; A quality checklist for gas calibration, steady state, missing data and protocol deviations Space: Desk / seated Automated structural checklist: 10 of 10 structural checks present Evidence quality/context: G5; Focused research depth Automated method-quality band: Comprehensive Method-rating basis: Structure coverage, instruction/check specificity, alternative distinctness, source troubleshooting, comparison depth and whether purpose/check fields are authored rather than derived. Editorial review: Pending manual editorial sign off ## Before you begin - [ ] I read the tutorial authority and stop conditions. - [ ] I have the required equipment/space or a declared accessible alternative. ## Canonical source context Metabolic flexibility is not a feeling or a voluntary switch that a person can train from a consumer score. In research it can mean change in fuel oxidation or respiratory exchange ratio (RER) when metabolic demand changes. RER is carbon dioxide produced divided by oxygen consumed during indirect calorimetry. This tutorial teaches how to define the construct, extract the laboratory conditions, check gas-quality data, calculate the declared change and keep insulin sensitivity, resting oxidation and exercise performance separate. It does not instruct fasting, diet, glucose, supplement or exercise self-experimentation. Target outcome: The learner produces a one-page audit of a metabolic-flexibility study that states the stimulus, population, calorimetry conditions, RER/substrate outcome, comparator, missing controls and claim ceiling. ### Authority and setup conditions - Choose one paper with a clearly described indirect-calorimetry or substrate-oxidation method. - Use only published, de-identified or fictional data; do not collect personal physiological measurements. - Write the research question before reading the results so the outcome is not redefined after the fact. - Mark clinical, fasting, exercise and sampling procedures as provider/laboratory controlled. ### Required or supplied materials - The full primary paper, protocol and supplementary methods - A data-extraction sheet with stimulus, timing, diet/fasting, prior exercise, gas system and population - A calculator or spreadsheet for supplied RER differences - A quality checklist for gas calibration, steady state, missing data and protocol deviations ## 1. Name the construct Copy the paper's exact definition of metabolic flexibility. State whether it means RER change, substrate oxidation, response to insulin/meal/exercise or another construct. Why: Different studies use the same label for different measurements. Success check: The audit contains one quoted or accurately paraphrased operational definition, not only the title term. Accessible alternative: Complete the same research action — “Copy the paper's exact definition of metabolic flexibility. State whether it means RER change, substrate oxidation, response to insulin/meal/exercise or another construct.” — using speech-to-text, text-to-speech, enlarged text, keyboard-only navigation, shorter work blocks or a support person. Preserve this declared check: “The audit contains one quoted or accurately paraphrased operational definition, not only the title term.” Do not convert the research task into capability practice. Alternative relationship: Target preserving when declared check is preserved Learner notes: ________________________________________________________________________________ Completed: [ ] ## 2. Draw the stimulus and time points List the baseline state, the metabolic challenge and every measurement time. Examples are fasted-to-fed, rest-to-exercise or low-to-higher workload. Why: A change score has meaning only across declared conditions. Success check: A reader can reproduce the sequence from the audit. Accessible alternative: Complete the same research action — “List the baseline state, the metabolic challenge and every measurement time. Examples are fasted-to-fed, rest-to-exercise or low-to-higher workload.” — using speech-to-text, text-to-speech, enlarged text, keyboard-only navigation, shorter work blocks or a support person. Preserve this declared check: “A reader can reproduce the sequence from the audit.” Do not convert the research task into capability practice. Alternative relationship: Target preserving when declared check is preserved Learner notes: ________________________________________________________________________________ Completed: [ ] ## 3. Extract the population Record sample size, age range, sex reporting, training status, obesity/diabetes criteria, medication exclusions and attrition. Why: Response and safety can differ across populations. Success check: The audit names who was studied and who was not. Accessible alternative: Complete the same research action — “Record sample size, age range, sex reporting, training status, obesity/diabetes criteria, medication exclusions and attrition.” — using speech-to-text, text-to-speech, enlarged text, keyboard-only navigation, shorter work blocks or a support person. Preserve this declared check: “The audit names who was studied and who was not.” Do not convert the research task into capability practice. Alternative relationship: Target preserving when declared check is preserved Learner notes: ________________________________________________________________________________ Completed: [ ] ## 4. Check standardisation Find diet control, fasting duration, time of day, prior exercise, caffeine/nicotine rules, workload and rest before gas collection. Mark each as reported, absent or unclear. Why: These conditions alter substrate oxidation and RER. Success check: No unreported control is assumed; the visible 'Check standardisation' check is satisfied. Accessible alternative: Complete the same research action — “Find diet control, fasting duration, time of day, prior exercise, caffeine/nicotine rules, workload and rest before gas collection. Mark each as reported, absent or unclear.” — using speech-to-text, text-to-speech, enlarged text, keyboard-only navigation, shorter work blocks or a support person. Preserve this declared check: “No unreported control is assumed; the visible 'Check standardisation' check is satisfied.” Do not convert the research task into capability practice. Alternative relationship: Target preserving when declared check is preserved Learner notes: ________________________________________________________________________________ Completed: [ ] ## 5. Audit indirect calorimetry Record gas analyser, calibration, mask/hood, averaging window and steady-state or plausibility rule. Flag RER values outside the study's physiological/technical range rather than silently deleting them. Why: Calibration and non-steady-state data can make fuel estimates unreliable. Success check: The quality table shows how each time point passed or failed. Accessible alternative: Complete the same research action — “Record gas analyser, calibration, mask/hood, averaging window and steady-state or plausibility rule. Flag RER values outside the study's physiological/technical range rather than silently deleting them.” — using speech-to-text, text-to-speech, enlarged text, keyboard-only navigation, shorter work blocks or a support person. Preserve this declared check: “The quality table shows how each time point passed or failed.” Do not convert the research task into capability practice. Alternative relationship: Target preserving when declared check is preserved Learner notes: ________________________________________________________________________________ Completed: [ ] ## 6. Calculate the declared response For supplied data, subtract baseline RER from challenge RER, or use the paper's prespecified oxidation formula. Keep the sign and units visible and do not invent a universal good direction. Why: The same absolute change can have different meaning under different stimuli. Success check: Another reader obtains the same calculation from the shown numbers. Accessible alternative: Complete the same research action — “For supplied data, subtract baseline RER from challenge RER, or use the paper's prespecified oxidation formula. Keep the sign and units visible and do not invent a universal good direction.” — using speech-to-text, text-to-speech, enlarged text, keyboard-only navigation, shorter work blocks or a support person. Preserve this declared check: “Another reader obtains the same calculation from the shown numbers.” Do not convert the research task into capability practice. Alternative relationship: Target preserving when declared check is preserved Learner notes: ________________________________________________________________________________ Completed: [ ] ## 7. Compare groups and outcomes Report within-person change and the between-group contrast with uncertainty. Keep resting oxidation, exercise oxidation, insulin sensitivity and performance in separate rows. Why: Correlation or change in one outcome does not establish change in another. Success check: The result table contains effect estimates and uncertainty, not just significant/not significant labels. Accessible alternative: Complete the same research action — “Report within-person change and the between-group contrast with uncertainty. Keep resting oxidation, exercise oxidation, insulin sensitivity and performance in separate rows.” — using speech-to-text, text-to-speech, enlarged text, keyboard-only navigation, shorter work blocks or a support person. Preserve this declared check: “The result table contains effect estimates and uncertainty, not just significant/not significant labels.” Do not convert the research task into capability practice. Alternative relationship: Target preserving when declared check is preserved Learner notes: ________________________________________________________________________________ Completed: [ ] ## 8. Write the claim ceiling State what the design supports, the key null/contrary finding and what it cannot establish. End with the next research need, not a lifestyle prescription. Why: A bounded conclusion prevents biomarker results becoming personal treatment advice. Success check: The final paragraph names at least one supported claim, one limitation and one prohibited inference. Accessible alternative: Complete the same research action — “State what the design supports, the key null/contrary finding and what it cannot establish. End with the next research need, not a lifestyle prescription.” — using speech-to-text, text-to-speech, enlarged text, keyboard-only navigation, shorter work blocks or a support person. Preserve this declared check: “The final paragraph names at least one supported claim, one limitation and one prohibited inference.” Do not convert the research task into capability practice. Alternative relationship: Target preserving when declared check is preserved Learner notes: ________________________________________________________________________________ Completed: [ ] ## Reflection What changed? ________________________________________________________________________________ What remains difficult? ________________________________________________________________________________ What will I repeat, adapt, ask for help with, or stop? ________________________________________________________________________________ --- Completion of this worksheet demonstrates tutorial participation only. It does not establish capability, qualification, safety clearance, diagnosis, treatment or independent validation.