A sports scientist investigated the effectiveness of two different pre-workout hydration drinks on athletic performance.
In Protocol A, 12 athletes drank 500 ml of a high-electrolyte solution 30 minutes before completing a 400 m sprint. In Protocol B, 12 different athletes drank 500 ml of a simple carbohydrate solution 30 minutes before completing the same 400 m sprint.
The results are given in Table 1 below.
Table 1: Average improvement in 400 m sprint times (compared to their baseline personal bests)
| Protocol A (Electrolyte) | Protocol B (Carbohydrate) |
|---|---|
| -0.8 seconds | -1.4 seconds |
After the results were recorded, the researcher asked all 24 participants to detail their dietary intake and sleep duration over the preceding 24 hours.
Suggest one possible extraneous variable in this experiment.
Practise AQA A Level Psychology Scientific processes with exam-style questions for A Level Psychology. 689 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.
