Weighted Vest with Velcro FastenerWhat Exactly Does the Weight Waistcoat in Different Weights Do for You? Put on your weight waistcoat whenever you want to train both strength and endurance during your normal workout. Thanks to the practical Velcro fasteners, the waistcoat fits like a glove and does not hinder your training, especially as it gives you full freedom of movement. The waistcoat is best used for the following exercises to provide an additional challenge: Back extension