The subject of cryotherapy("cold therapy") is a controversial one. Ice baths for example have been used by elite athletes for decades to help in post workout recovery. I personally am a big fan of ice baths and have used them as a recovery tool for years. I always feel invigorated and energized when I'm done. I also sleep like a baby a couple hours afterwards when I have warmed up and call it a night. The great nights sleep in itself is an invaluable tool in recovery. Research shows many benefits,but also some negative effects if not done correctly and sparingly.

Lets go over some of the benefits first;
1.Improves circulation
2.Reduces inflammation
3.Speed recovery-helps prevent DOMS(delayed onset muscle soreness)
4.Increase metabolism
5.Strengthens immunity
6.Can increase testosterone in men
7.Increases energy & wellbeing
8.Relieves depression
9.Keeps skin and hair healthy

  Using ice baths/cryotherapy basically works by constricting blood vessels and decreasing metabolic activity which reduces swelling and tissue breakdown. Once you are no longer in contact with the cold water the tissue starts to warm up. As it warms the blood flow return is much faster and has a flushing effect on lactic acid and other byproducts of cellular breakdown to the lymph system for efficient recycling. Ice baths decrease muscle pain and inflammation and help prevent DOMS(delayed onset muscle soreness)  because of this flushing of byproducts.
  Another benefit is that your metabolism is increased and it can accelerate fat loss. The reason for this is simply that your body will burn any fuel it has to stay at it's optimal operating temperature. Cold water is bar none the most efficient way to quickly decrease body heat and kickstart your bodies fat burning furnace. The best part is the calories burned for heat mainly come from fat. In Timothy Ferris's book The Four Hour Body, Ferris wrote a section called "Ice Age Revisited". Ferris has experimented with cold showers,ice packs,and ice baths. What he has concluded is that there are two distinct types of fat tissue. White adipose tissue(WAT) and brown adipose tissue(BAT). Until recently it was thought that BAT was only present in infants and small children and that adults only have WAT. It turns out that adults do have BAT and it is predominantly in the neck and upper chest & back. BAT helps dissipate calories as heat instead of storing them as WAT. BAT is known as fat burning fat. So cold stimulates BAT to burn fat and glucose as heat,especially when you get to a light shiver. I have personally tried this for fat loss and had surprisingly good results.
  The Thrombrosis Research institute showed that cold water exposure can increase testosterone in men. Cryotherapy has also been shown to stimulate a chemical called noradrenaline. Low noradrenaline has been linked to depression. Another benefit I have had from ice baths is tight,healthy skin. Cold water contracts pores and improves circulation to the skin for healthier hair and skin.
  I know that so far ice baths sound like the greatest thing around,but there is research evidence that shows a considerable down side for some people and if overused.
  First off if you are not a generally healthy person and have heart disease,high blood pressure,or if you are sick with fever,you should avoid ice baths like the plague. The contraction of blood vessels can cause stroke in people with high blood pressure. The other big issue falls into the realm of athletes using ice baths regularly for recovery. The issue is ROS(reactive oxygen species). ROS are chemically reactive molecules containing oxygen. ROS form as a natural byproduct of the normal metabolism of oxygen and have important rolls in cell signaling and homeostasis. So all this mumbo jumbo that I don't  understand was explained to me like this. When you train hard your body generates ROS as an inflammatory response so you can recover. There simply is a need for an inflammatory response to help heal. ROS are essential to allow your body to increase it's anti oxidant defense mechanism. A stronger defense mechanism will allow you to withstand more ROS production during your next workout. So to destroy all of them is harmful. So the cooling effects of an ice bath generates less ROS and decreases the inflammatory reaction. So long term if you don't have an effective inflammatory reaction you cannot properly repair your muscle.
  All this being said I think that if used as a tool and not overused, ice baths have great benefit. I don't use them right after training so that the inflammatory response does it's work and I only use them 1-2 times weekly a couple hours before bed. I can tell you that once you get used to the cold you will feel amazing and have an amazing nights sleep. When you wake up the next day you will feel great and not feel beat up or tired.
  If you want to try out Cryotherapy you have to start very slowly. Cold packs on different parts of body and on the back of neck. Transition into cold showers and when you are ready try the ice bath. Even then start slow. Break it into three parts. Sit in water to the waist for half the time,then up to chest arms out 1/4 time and fully submerged arms in and water to chin the last 1/4.

 My personal checklist for ice bath;
-Fill up tub half way with cold water.
-Put 30lbs of ice in tub if average size.
-Wait until ice is 80% melted
-Water should be 50-59 degrees F
-Get in for 10-20 minutes(never more than 20)
-10 min waist deep,5 min up to chest arms out,5 min fully submerged arms in and water to chin.
-Get out and get dressed while letting your body heat up on its own. No hot shower needed.

Ares Nikolopoulos