A sports scientist conducted a trial to investigate whether long-distance runners who consumed a high-nitrate beetroot juice supplement daily differed from those who consumed a placebo juice in relation to their aerobic endurance. To do this, he needed to standardise the runners' weekly training volume and decide how to measure his dependent variable.
Identify the independent variable and the dependent variable in this trial.
689 exam-style questions on AQA A Level Psychology Scientific processes. Each one has a worked solution and a mark scheme showing where the marks go.