Exploring and designing practice questions.

A student wants to investigate recovery in team-sport players. Which research question is best operationalised for a school investigation?

• Is a longer rest between efforts better for team-sport athletes who sprint repeatedly?
• How does rest interval (30, 60 or 120 s) affect mean 30 m sprint time in hockey players?
• Which physiological factors are responsible for fatigue during repeated sprinting in team sports?
• Does fitness training improve the recovery and the sprinting ability of hockey players over a season?

Answer: How does rest interval (30, 60 or 120 s) affect mean 30 m sprint time in hockey players?

An operationalised question names the independent variable with its levels, the dependent variable with the measurement used and the population studied. The other three either use an unmeasurable term such as 'better', or leave the variable undefined, so no protocol can be written from them.

Netball players complete a vertical jump test after five minutes of static stretching, after five minutes of dynamic stretching and after seated rest. Jump height is measured on a jump mat, and footwear, time of day and mat position are held constant. Which is the independent variable?

• The jump height recorded by the jump mat
• The position of the jump mat in the sports hall
• The time of day at which each player is tested
• The type of warm-up completed before the jump

Answer: The type of warm-up completed before the jump

The independent variable is the one the researcher deliberately sets at different levels, here three warm-up conditions. Jump height is the dependent variable that is measured in response, and the remaining two are control variables held constant.

A student compares resting heart rate in trained swimmers and in untrained classmates of the same age. Which variable most needs to be standardised for the comparison to be fair?

• Whether each participant is a swimmer or a non-swimmer
• The resting heart rate recorded for each participant
• The time since each participant last exercised
• The number of participants recruited into each group

Answer: The time since each participant last exercised

Recent exercise keeps heart rate elevated for a long time, so it would systematically shift one group's readings and be mistaken for a training effect. Training status is the independent variable and heart rate is the dependent variable, so neither can be standardised.

A student plans to measure grip strength in a class of 15-year-old participants. Which requirement must be met before testing begins?

• Consent from a parent or guardian in addition to the participants' assent
• The participants' own written agreement alone, because the test is submaximal
• No agreement at all, provided the grip strength scores are recorded anonymously
• Approval from the school first-aid officer instead of agreement from the participants

Answer: Consent from a parent or guardian in addition to the participants' assent

Participants below the age of majority give assent, but legally valid consent must come from a parent or guardian, and both are needed. Anonymity protects the data afterwards and does not replace agreement to take part.

Before collecting data, a student runs the full Wingate protocol on two volunteers who will not take part in the main study. Which statement identifies the main purpose of this trial?

• To increase the sample size of the investigation
• To check the protocol, timings and equipment settings before data collection
• To provide the control group against which the main results are compared
• To confirm that the expected result appears before the main data are collected

Answer: To check the protocol, timings and equipment settings before data collection

A pilot study tests the procedure rather than the hypothesis: it exposes unclear instructions, an unworkable resistance setting or a timing conflict while they can still be changed. Its data are kept out of the main results because the protocol may then be altered.

A maximal incremental treadmill protocol lists termination criteria that are agreed with the supervising teacher before testing starts. Which is an appropriate pre-defined termination criterion?

• The participant's heart rate exceeds 60 % of estimated maximum heart rate
• The participant's blood lactate concentration reaches 2 mmol L-1
• The participant asks how many stages of the test are still to come
• The participant reports dizziness or chest discomfort

Answer: The participant reports dizziness or chest discomfort

Termination criteria are signs of distress that are written down before testing so that nobody has to judge them under pressure during the test. A heart rate of 60 % of estimated maximum and a lactate of 2 mmol L-1 both occur in routine submaximal work and would stop the protocol long before it is maximal.