What does heat do?
This increases blood flow to a specific area. Deoxygenated blood can flow out and flush away the built up metabolic waste. Meanwhile, new blood can flow in, bringing nutrients and oxygen to promote recovery.
Injury causes nerves to constantly send pain signals to the muscle. This nerve irritation can be distracted with overriding heat signals.
Muscles tend to tense up and spasm when there is pain. As explained above, heat diminishes pain signals from the nerves. Tension then declines due to the decrease in pain.
* For optimum effects: heat 10 min, off for 10 min, repeat 2 – 3 times.
**Do not heat an acute/recent injury! The vessels at the injury site are still weakened and cannot handle an increase in flow.
The cold constricts the blood vessels. Blood flow to the injury site lessens when ice is applied, thus lessening swelling and pain.
The ice will numb the nerves in the area, decreasing soreness. It will also slow the nerve impulses, thus lessening the degree of pain and pain-spasm reaction.
*For optimum effect: ice until skin is pink (10 min), off 10 min, repeat 2 – 3 times
**Use a wet towel as a barrier between your skin and the ice to avoid freezing the skin.
Heat allows the blood vessels to dilate; cold then contracts them. Alternating between the two acts as a pump and increases the circulation in the area to:
The ratio of heat to cold should be 3 min : 1 min.
Repeat 3 times.
Always end with cold.
Ending with heat leaves the blood vessels dilated, allowing for fluid to accumulate again. Rather than re-aggravating the injury, end with cold to constrict the vessels. This will minimize the return of any swelling.
(Depends on injury/person; 2 days – 2weeks)