Elite level athletes train and perform at a high level of intensity, demanding physiological recovery from fatigue in the musculoskeletal, nervous and metabolic systems, with the potential of exercise-induced muscle damage (EIMD) and the resulting delayed-onset muscle soreness (DOMS) leading to a decrease in subsequent performance.
As a result, more and more medical and performance teams are turning to Whole Body Cryotherapy (WBC), in order to enable an accelerated and manage recovery from fatigue and to minimise or postpone the impact of EIMD or DOMS. But how does WBC work at a physiological level?
Pain relief and anaesthesia
Systemic cryotherapy results in anaesthesia and activates an internal analgesic reaction. The influence of low temperatures on skeletal muscle relaxation is explained by a decrease in the inflow of pain impulses to the spinal cord. What is also of significance is the fact that an opening and closing reaction of the arteriovenous fistulae takes place within the limbs.
All this creates favourable conditions for the progress of rehabilitation, while the conditions may be intensified and extended. The systemic application of cryogenic temperatures results in a specific form of thermoregulation, the consequences of which are extremely beneficial locally, while the total of these consequences provides an effective method of biological regeneration. A marked increase in organism immunity has also been noted. It is worth noting that the implementation of cryogenic temperatures on the human organism is not merely applied in medicine when treating patients, but also in the case of perfectly healthy people, engaging physical effort in professional or recreational sport.It is an ideal method for biological regeneration, enabling a fast and effective way to regenerate the body after strenuous effort. Cryotherapy also contributes to faster alleviation of varied conditions,especially pain-related ones, occurring while doing sports.
Post exercise, fibres of stressed muscles require more energy to repair the inevitable resulting damage. Applying cryotherapy, minimises the energy demanded by muscles by reducing the stress on each fibre through the inequality of oxygen levels. Studies have shown reduced perfusion and oxygen usage by muscles when cooled at rest and post exercise, leading to the conclusion of a reduced aerobic metabolic rate. Further studies have also indicated an enhanced metabolic clearance as well as a reduction in the accumulation of metabolic waste. Tests have also indicated that muscle acidosis, a contributory factor in peripheral fatigue, is substantially reduced in muscles post WBC treatment.
Whole Body Cryotherapy invokes vasoconstriction, a narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels. The treatment leads to a reaction in the adrenergic receptors for norepinephrine in the vascular walls which leads to the inflammatory response to cold treatment as part of recovery. Reducing blood flow to fatigued muscles has a direct influence on counteracting swelling as muscle fibres with disruption and the sarcolemma (cell membrane) level or blood chemistry which carry a risk of oedema. Intensive exercise also increases the effect on blood flow to the various parts of the body which has a detrimental impact on the delivery of oxygen. The application of whole body cryotherapy with vasoconstriction carries a reduction in –
- muscle fibre oedema and resulting pain,
- functional impairment,
- the potential for damage caused by inflammation.
Fluid shunting & oedema
In general, oedema is caused by increased activity at the muscle membrane level leads to pain, decrease in muscle effectiveness and issues with the delivery of oxygen to the area. WBC has been shown to reduce blood flow to muscle fibres that have been compromised as a result of physical exercise. This in turn, reduces the impact of swelling at a cellular level. Furthermore, studies also indicate that cold treatments such as Cold Water immersion, taking place over a long duration (>30min) could have a detrimental impact and actually increase oedema, as they have been shown to result in cold damage to cells. Due to WBC taking place over a very short period, this potential is negated.
Intensive physical exercise places muscles under stress, leading to soreness which leads to a degradation in muscle performance. Muscle fibre become traumatised with the potential of inducing muscle spasms. Applying WBC has the effect of reducing nerve conduction velocity and as a result, the pain and sensation of pain and reflexive spasms are mitigated.
WBC can alter the neural activity of the heart as well as rejuvenate central blood volume and enhance cardiac preload. The impact of these changes are shown to improve recovery from metabolically stressful exercise.A number of studies have indicated that extreme cold treatments provide enhanced cardiac efficiency with lower heart rates, increased cardiac output and increased stroke volume.
WBC has been found to have an immunostimulating effect as a result of the nor-adrenaline (norepinephrine) response to cold. Studies have indicated that WBC treatment increased immunoglobins which has also been found to have paracrine effects.