IB Sports, exercise and health science (SEHS) SL Extended Essay Example

The student states a clear, relevant research question and keeps the investigation centered on a specific distance, group, and outcome.

The student identifies the key variables in a way that makes the experimental design easy to follow.

The student includes a range of relevant methodological details such as screening, piloting, and repeated-measures planning.

The intervention changes more than hydration timing because water breaks also alter pacing and effort.

The question and method do not fully separate heart-rate response from broader claims about thermoregulation or performance.

Some source choices and variable definitions are not precise enough for a fully focused investigation.

The student shows solid understanding of the physiological ideas behind hydration, cardiovascular drift, and exercise heart rate.

The student uses a good range of subject terminology, including several terms that are relevant to the topic.

The student generally applies scientific language to support their prediction and explanation.

Some explanations go beyond what the student's investigation can directly show, especially when heart rate is treated as evidence of thermoregulation.

A few physiological statements are too absolute or imprecise, which reduces confidence in the accuracy of the background.

Several claims about performance and recovery are not matched by the data the student actually collected.