types of stretching: static and dynamic. Static stretching is better at creating a more intense stretch because it is able to isolate a muscle group better. But this intensity of stretching may hinder one's athletic performance because the muscle is being overstretched while held in this position and, once the tension is released, the muscle will tend to tighten up and may actually become weaker than it was previously. Also, the longer the duration of static stretching, the more exhausted the muscle becomes. This type of stretching has been shown to have negative results on athletic performance within the categories of power and speed. However, to be able to do usual daily activities, a certain amount of range of motion is needed from each muscle. For example, the calf muscles are one of the muscle groups that have the most need for adequate flexibility since they are deeply related to normal lower limb function. When the goal is to increase flexibility, the most commonly used technique is stretching. Chronic static stretching was shown to increase range of motion of Dorsiflexion or bringing one's foot closer to their shin by an average of 5.17 degrees in healthy individuals versus 3.77 degrees when solely using ballistic stretching. Still, ballistic stretching is likely to increase flexibility through a neurological mechanism. The stretched muscle is moved passively to the end range by an external force or agonist muscle: holding a muscle in this position might reduce muscle spindle sensitivity, with repeated stretch applied at the end range inhibiting the Golgi tendon organ. Dynamic stretching, because it is movement-based, may not isolate the muscle group as well or have as intense of a stretch, but it is better at increasing the circulation of blood flow throughout the body, which in turn increases the amount of oxygen able to be used for athletic performance. This type of stretching has shown better results on athletic performances of power and speed when compared to static stretching. However, both of these types of stretching have been shown to have a positive impact on flexibility over time by increasing muscle and joint elasticity, thus increasing the depth and range of motion an athlete is able to reach. This is evident in the experiment "Acute effects of duration on sprint performance of adolescent football players". In this experiment, football players were put through different stretching durations of static and dynamic stretching