One group pretest post-test design

One Group Pre-Post Design Methodology A common example of Pre-Experimental Designs A common example of Pre-Experimental Designs –No control group –No random selection of participants –Little power to establish causation One Group Study Design One Group Study Design –Select/recruit volunteers –Administer pre-test –Provide Treatment –Administer post-test

Development of Race Profiles for the Performance of a Simulated 2000-m Rowing Race Kennedy & Bell, 2003

Research Purpose Research Purpose -To create race profiles of men and women rowers before and after training using a simulated 2000-m rowing race. -To create race profiles of men and women rowers before and after training using a simulated 2000-m rowing race. -To observe the effect of: -To observe the effect of: -Men vs. women -Before vs. after training

Study Design and Methodology Subject characteristics Subject characteristics –Recruited from local rowing clubs –Actively training for preceding 3 months –7 male, 11 female novice rowers –12 male, 8 female experienced rowers Informed consent & Ethics approved by U of Alberta and Faculty of Phys.Ed.

Study Design and Methodology Race Simulation Structure Race Simulation Structure –2000 meter race in lowest time –Performed on a Concept II Model C –Time, distance, stroke rate, 500-m split time displayed for rowers –HR, split time/500-m time & stroke rate recorded every 200-m.

Study Design and Methodology Testing Protocol (Before & after training) Testing Protocol (Before & after training) 2000-m simulated race time 2000-m simulated race time Combined VT/VO2max test Combined VT/VO2max test –Horizon metabolic cart –Polar Heart Rate monitor Multiple Repetition Maximum tests Multiple Repetition Maximum tests

Study Design and Methodology Training Treatment Specifics Training Treatment Specifics Ten week program: Ten week program: –Individually prescribed and periodized –Progressive overload Strength Component: 2x/week Strength Component: 2x/week –Upper and lower body exercises –65-90% predicted 1-RM Aerobic Component: 4x/week Aerobic Component: 4x/week –Three continuous and one interval workout –Performed on Concept II Model C

Data Analysis All variables collected manually from the Concept II display (stroke rate, time, distance, 500-m. split time) All variables collected manually from the Concept II display (stroke rate, time, distance, 500-m. split time) Used to calculate velocity, mean race velocity (MRV), deviation from MRV, and standard deviation of MRV every 200-m. Used to calculate velocity, mean race velocity (MRV), deviation from MRV, and standard deviation of MRV every 200-m.

Data Analysis Mean Race Velocity (MRV) Mean Race Velocity (MRV) –Average of all race velocities taken at 200-m. intervals Deviation from MRV Deviation from MRV –Specific race velocities taken at 200-m. intervals minus MRV Standard Deviation from MRV Standard Deviation from MRV –Average deviation of all participants from their mean race velocity at a given interval

Data Analysis Race Profile Definition: Race Profile Definition: –Provides a descriptive graphical illustration of spontaneous pacing behavior –Is a known factor in sport performance that has received little attention in the sport of rowing –Deviation from MRV plotted against MRV

Major Findings Physiological Improvements Physiological Improvements Female Pre Female Post Male Pre Male Post VO 2 Max 37 ml/kg·m m 539 sec Leg Press 148 kg Bench 18 kg

Race Profile (Male Pre-test)

Race Profile (Male Post-test)

“Constant Pace” (Fast Male Post)

“All-Out” (Fast Female Post)

Major Findings Differences in pacing with training Differences in pacing with training –Moved toward a constant pace model and improved pace Differences in pacing between genders Differences in pacing between genders –Fastest males adhered most closely to the constant pace strategy –Fastest females adhered to an all-out strategy not adopted by any other groups

Discussion All-out pace profile (fastest women) All-out pace profile (fastest women) –Close to higher intensity sports –Unknown if adhering to a constant pace would have resulted in improved performance Constant pace profile (fastest men) Constant pace profile (fastest men) –Close to similar well-documented sports Short duration cycling (4000-m.) Short duration cycling (4000-m.)

Critique Pre-post inability to establish causation Pre-post inability to establish causation –has no control group Learning effect (author’s critique) Learning effect (author’s critique) Possible that fastest female rowers were novice Possible that fastest female rowers were novice During 2000 m test verbal encouragement used During 2000 m test verbal encouragement used – could affect final results Compared group vs. 3 fastest rowers of each sex Compared group vs. 3 fastest rowers of each sex –should have compared novice vs. experienced rowers

Critique cont’d Tested during off-season Tested during off-season –rowers not in physical or mental shape of race Transferability not good Transferability not good –test is on rowing ergometer vs. boat in water –racing strategy often dependent on situation relative to competitors

Suggestions/Future Considerations Need to assess elite level competition to strongly establish nature of optimal race strategy etc. Need to assess elite level competition to strongly establish nature of optimal race strategy etc. Done on water (author’s suggestion) Done on water (author’s suggestion) Compare matched groups using alternate approaches Compare matched groups using alternate approaches Compare all out strategy vs. constant for 2000 m race Compare all out strategy vs. constant for 2000 m race

Other Possible Questions for Similar Research Specific to rowing Specific to rowing –what is psychologically going on during the race General for Pre-Post design General for Pre-Post design –add a control group –eg. Choosing own method of rowing vs. racing strategy