Measuring the relationship between self-determined motivation and improvements in an off-season strength and conditioning program
This mixed-methods study looked at the relationship between self-determined motivation and strength improvements in an off-season strength and conditioning program. The Intrinsic Motivation Inventory (IMI; Ryan, 1982), which assesses motivation according to the tenets of Self-Determination Theory (SDT; Deci & Ryan, 1985) measured self-determined motivation in this study. Strength was measured by the Epic Strength Index (ESI; Epley, 2004), which factors the amount of weight lifted along with the bodyweight and gender of the athlete to determine a strength index. Strength improvement was measured as the difference between ending and beginning ESI scores. The participants consisted of one-hundred-twenty-seven male and female athletes ranging between 14-22 years of age and representing a variety of sports including several multi-sport athletes. Each participant was tested in the Power Clean, Bench Press, and Squat at the beginning and end of the program as part of their regular training program. During the second week of the program, the athletes completed the IMI. The amount of weight each athlete lifted in each of the three weightlifting exercises was computed by the ESI yielding an individual strength index for each lift, along with a total score for all three lifts. Correlation and regression analyses revealed a significant relationship between self-determined motivation and strength improvements. The average of all IMI scores independently predicted 50.65% of the variance in strength improvements. Correlation analysis also showed significant relationships for gender and age on ESI improvements, in that females and younger athletes tended to improve more. When a regression analysis accounting for the effects of gender and age on strength improvements was performed, Self-determined motivation still predicted 49.54% of the improvements. At the conclusion of the study, eight of the athletes participated in qualitative interviews. The eight participants represented two male and two female participants from both the top and bottom quartiles of average IMI scores. The qualitative interviews from the work of Hassandra, Goudas, and Chroni (2003) and Vazou, Ntoumanis, and Duda (2005) who used qualitative analysis to study differences in motivational patterns of secondary physical education students and 14 to 16 year-old athletes respectively. The interview questions were formulated to determine factors that affected the initial decision to participate in the program, as well as to discern differences among the top and bottom quartiles participants. The qualitative analysis revealed many similarities and some differences between those in the top and bottom quartiles of motivation. Athletes in both categories mentioned motivation for improvement as the prime reason for participation and as a rewarding aspect of the program. Also common to both groups of athletes was the important role of teammates and coaches in deciding to participate in this program. The main difference between the top and bottom quartiles was in the discussion of "least enjoyed aspects of the program" and "difficulties of the program". While those in the top quartile of motivation reported to that they mostly liked the program and mentioned only transportation as a difficulty of the program, those in the bottom quartile provided a wide variety of responses to these questions.