We have all heard the advice to "go punch a pillow" when stressed, anxious, or angry. Many of us, especially those of us who are parents, will even have dished this advice out. Others, however, feel that emotional closeness to other people and physical comfort are more effective as relaxation techniques for anxiety.
Who is right? What is the better way of dealing with anxiety?
Physically 'Aggressive' Activities To Cope With Anxiety
The catharsis theory of aggression is the idea that physically venting one's angry emotions leads to closure, acceptance, and a reduction in symptoms. Advocates of this theory may advise someone to punch a pillow, kick around a ball, or scream to "let their emotions out", and consequentially resolve them and become less angry.
Does it work as a way of dealing with anxiety, though? The answer is a resounding "no". Those people who were encouraged to think about becoming physically fitter while using a punching bag in a research setting, and those who did nothing in particular about their anger, fared better than those who were instructed to think about the subject of their anger while hitting a punching bag. Those who thought about the people they were angry with while using a punching bag were even found to take their anger out on completely unrelated third parties afterwards, showing that catharsis can actually increase someone's overall anger. 
This is relevant to many people with anxiety disorders, as anxiety has been shown to be linked to anger issues. 
The finding that the catharsis theory of aggression — the idea that venting your anger physically resolves it — has been debunked does not mean that no physical activity that could be considered aggressive can help lower your anxiety. On the contrary, regular exercise is strongly correlated with a reduction in anxiety levels , and research shows that aerobic exercise is generally more effective at reducing anxiety levels in people suffering from anxiety disorders .
People with anxiety disorders, such as social anxiety disorder, generalized anxiety disorder, and panic disorder should therefore engage in "aggressive" physical activities with thoughts of overall wellbeing and health in their minds. Exercise thus takes on the role of being a soothing activity, in fact one of the most effective relaxation techniques for anxiety and stress, as opposed to a way to vent anger.
Soothing Physical Touch To Manage Anxiety
When you hug someone you love and desire physical closeness with, your levels of the love hormone oxytocin get a boost, and your anxiety reduces significantly — something that, interesting, does not occur during unwanted hugs , Being hugged by someone you care about is, thus, an effective anxiety relief technique which you can combine with other ways of coping with anxiety and stress.
Temple Grandin's hug machine, a mechanical device that applies a hug-like pressure, has been shown to have great potential in helping reduce the symptoms of anxiety disorders in children with autism. This shows that the benefits of hugs are not merely derived from social closeness, but that the physical action of hugging itself offers comfort to some people.  Mechanical hugs may thus be beneficial to people suffering from social anxiety disorder, who often avoid the close touch of others, as well.
Massage therapy, which produces muscle tension relief as well as physical closeness with another person, has likewise been shown to reduce anxiety and stress . While the mechanism of action is not yet fully understood, we do know that massage therapy plays the role of reducing a person's levels of the stress hormone cortisol, as well as possibly making the recipient feel cared for — in much the same way a hug would. 
So, What's Better If You Want To Reduce Anxiety? Hugs Or Aggressive Physical Activity?
Since research shows that venting your anger increases rather than decreases it, we can't recommend punching pillows, screaming, or kicking while thinking about the object of your anger as a coping technique for angry people with anxiety.
Engaging in aggressive physical activities to improve your overall wellbeing and fitness is, however, beneficial — and because studies show that being outside in nature reduces stress levels , it is best if you engage in this physical activity in the great outdoors.
Hugging, both physical closeness with people you care about and the mechanical action of hugging, also is another way of dealing with anxiety.