While it is often recommended that people do stretching exercises before they workout, two new studies suggest that doing so can weaken your workout.

The second study, published in the Scandinavian Journal of Medicine and Science in Sports, analyzed articles published over the last four decades which looked into the effect caused by static stretching on athletes’ strength, power and explosive muscle performance when engaged in their sport. The researchers found that regardless of an athlete’s gender and age, static stretching negatively affected the performance.
“We can now say for sure that static stretching alone is not recommended as an appropriate form of warm-up. A warm-up should improve performance not worsen it”, lead researcher of one of the studies, Goran Markovic, from University of Zagreb, said.
Source-Medindia