A sports scientist wanted to investigate whether consuming high-polyphenol dark chocolate improves post-exercise arterial stiffness in distance runners. Previous research suggests that dietary polyphenols enhance nitric oxide production, which may reduce arterial stiffness after high-intensity exercise.
The researcher used a repeated measures design with a sample of 18 competitive club-level distance runners.
Immediately after each run, the researcher measured the participants' arterial stiffness using pulse wave velocity (PWV) in meters per second (m/s\text{m/s}m/s), where lower values indicate more flexible arteries.
Explain why a repeated measures design was more appropriate than an independent groups design in this study.
Practise AQA A Level Psychology Scientific processes with exam-style questions for A Level Psychology. 100 questions, matched to the AQA A Level Psychology (7182) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.