Yesterday I learned that a pilot study presented at the American College of Sports Medicine’s 57th Annual Meeting on June 4, 2010 has confirmed my observations. The report states:
Researchers compared the two techniques’ effect on flexibility of the same muscle/joint complexes in a five-week intervention.
“The results suggest that carefully constructed, full-range resistance training regimens can improve flexibility as well as—or perhaps better than—typical static stretching regimens,” said James R. Whitehead, Ed.D., FACSM, presenting author of the study.
Twenty-five college-age volunteers were randomly assigned to groups performing either resistance training or static stretching. A 12-person control group remained inactive. All were pre-tested on hamstring extension, hip flexion and extension, and shoulder extension flexibility, as well as peak torque of quadriceps and hamstring muscles. The resistance training and stretching programs focused on the same muscle-joint complexes over similar movements and ranges. Post-tests measured flexibility and strength.
The results—which may surprise advocates of stretching to improve flexibility—showed no statistically significant advantage of stretching over resistance training. Resistance training, in fact, produced greater improvements in flexibility in some cases, while also improving strength. [Italics added]
Although this was a "preliminary" study, I have no doubt that the larger study planned will have the same outcome. Properly performed, strength training can give you strength, flexibility, and cardiovascular fitness as well.