Evaluation of warm-up for improvement in flexibility.

The purpose of this investigation was to evaluate the effects of warming the joints by jogging and then stretching on increases in joint flexibility. Subjects were 51 students enrolled in a physical conditioning class assigned to a jog and then stretch (JS), stretch and no jog (S), or a control group (C). Both the JS and S groups performed a series of stretching exercises 2 days a week for 9 weeks, with the JS group jogging for 5 minutes prior to stretching. Subjects were pretested and posttested for shoulder, hamstrings, trunk, and ankle flexibility with a Leighton flexometer. Results of t-tests indicated that significant increases in flexibility occurred for all of the joint angles evaluated for both the JS and S groups with the exception of trunk flexibility for the JS group. An analysis of variance (ANOVA) of gain scores indicated a significant gain in ankle flexibility for the JS group compared to S and C groups. The S group produced a significant gain in trunk flexibility compared to the JS group. Both JS and S groups were effective in improving flexibility, but when the gain scores were compared the results were variable. The data from this study again demonstrate that increases in flexibility can occur as a result of a static stretching training program. However, the results do not support the claim that warming the muscles prior to stretching by jogging will result in significant increases for all of the joint angles evaluated. Both methods offer possible advantages associated with improving joint flexibility.