Students measure their reaction time before and after an induced fatigue condition and compare changes in average reaction time and variability. The class explores how mental or physical fatigue influences response speed and consistency.

1. Gather materials: stopwatch or reaction-time website, 30 cm ruler (for ruler-drop test), masking tape, clipboard/data sheets, pencil, light weights or bodyweight exercise space, optional laptop or tablets.
2. Form pairs. Assign roles: Tester and Participant. Switch roles halfway through.
3. Choose at least two reaction-time methods: (A) online click test, (B) ruler-drop test. Practice each method twice to learn the technique.
4. Collect baseline data. Record 5–10 trials per method while the participant is rested. Note both reaction time and any obvious outliers.
5. Induce mental fatigue for Group 1: 8–12 minutes of continuous attention task (e.g., Stroop-like color-word list, rapid mental arithmetic, or sustained target detection with few breaks).
6. Induce physical fatigue for Group 2: 6–8 minutes of moderate continuous exercise matched to ability (e.g., wall sit intervals, step-ups, light shuttle runs, or brisk marching in place). Keep it safe and submaximal.
7. Immediately repeat the same reaction-time tests. Record 5–10 trials per method post-fatigue.
8. If time allows, cross over conditions on a different day or after full recovery so each participant completes both mental and physical fatigue sessions.
9. Calculate for each condition and method: mean reaction time, range, and standard deviation if possible. Mark the slowest and fastest trials.
10. Compare baseline vs post-fatigue within individuals and across the class. Look for changes in average speed and in variability.
11. Discuss results and possible explanations. Consider which fatigue type produced the larger effect and why.

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• Use a choice reaction-time task with two keys or two colored targets to compare simple vs choice reaction time.
• Add a mild sleepiness condition by testing early morning vs mid-afternoon on different days.
• Test a brief recovery: measure immediately after fatigue, then again after 3 and 6 minutes of rest.
• Introduce a caffeine-free alertness aid such as a short breathing or stretching break and compare pre vs post.
• Scale up with a classwide dataset and construct histograms of reaction times for each condition.

• Obtain teacher approval for the exercise protocol and screen for injuries or conditions that limit physical activity.
• Keep physical fatigue submaximal; stop immediately for pain, dizziness, or shortness of breath.
• Provide water and allow rests between sets; ensure adequate space free of obstacles.
• Use only light loads or bodyweight movements; no maximal lifting.
• For ruler drops, keep hands clear of faces and eyes; no tossing or striking.
• Sanitize shared devices and rulers between users if needed.
• If any participant cannot exercise, substitute a seated mental-fatigue task to ensure inclusion.

• Which changed more with fatigue: the average reaction time or the variability of trials? (Often both increase, but variability can grow noticeably.)
• Did mental fatigue or physical fatigue have a larger effect in your class? (Answers may differ; compare group means and ranges.)
• Why might choice reaction time be more affected than simple reaction time? (It requires additional decision and attention processes.)
• How much recovery time restored reaction speed toward baseline? (Look for partial recovery within a few minutes, depending on the task.)
• What factors besides fatigue could have influenced your measurements? (Practice effects, motivation, time of day, distractions, and measurement error.)