One of the studies, which has been published in the Journal of Strength and Conditioning Research, suggests that static stretching before lifting weights make the athletes feel weaker by altering or impairing the neurological function in active musculature.
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.