Which type of stretching is generally recommended to be avoided for increasing flexibility?

Ballistic stretching is generally recommended to be avoided for increasing flexibility because it involves vigorous movements that push muscles beyond their normal range of motion in a bouncing or jerking manner. This type of stretching can lead to muscle strains and injuries, as it often does not allow the muscle to adapt gradually.

In contrast, static stretching involves holding a stretch in a fixed position, promoting relaxation and lengthening of the muscle without undue stress. Dynamic stretching incorporates controlled movements that enhance flexibility and prepare the muscles for activity, while proprioceptive neuromuscular facilitation (PNF) is a technique that combines stretching and contracting of the muscle to improve flexibility. These methods are more effective and safer for achieving increased flexibility compared to ballistic stretching.