A sports scientist is investigating whether a new high-intensity interval training (HIIT) protocol is more effective at reducing 5 km running times than a traditional continuous tempo training (CTT) program.
The scientist uses a matched-pairs design. She recruits 30 amateur runners from a local running club who volunteer to participate.
Participants in Group A are prescribed a structured 8-week HIIT program (three 30-minute sessions per week). Participants in Group B are prescribed a structured 8-week CTT program (three 30-minute sessions per week). All participants are instructed to keep their dietary habits constant and to refrain from any other structured cardiovascular exercise for the duration of the 8-week study.
The 5 km run time of each participant is recorded under standard conditions at the start and at the end of the 8-week period, and the reduction in run time (in seconds) is calculated.
Identify one variable on which participants should be matched in this matched-pairs design. Explain how the researcher could assign matched participants to either Group A or Group B.
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.