I have been preaching the merits of stretching for years, and now I have another reason to add to my familiar sermon. A recent study showed that it might actually make people stronger and increase their endurance.
It is believed that stretching works muscles in a similar fashion as strength training, but on a much smaller scale. Researchers suspect that stretching stimulates cells in the same way as other forms of exercise. Stretching is more than just increasing the range of motion, but it will never take the place of strength training or cardio. It is, however, quite complementary and should be included in any fitness program.
While study participants stretched for 40 minutes, three times a week, the researchers believe that it is unlikely for most people to dedicate that amount of time to stretching. If you don't have an extra two hours a week to dedicate to stretching, then you should aim to at least stretch all your major muscles a few times a week.
Looking for some good stretches? Check out the Stretch It series. You will surely find a suitable stretch for your major muscle groups.