it is called the warm up
they warm up their muscles to avoid damaging them
Athletes warm up to loosen up muscles so that they don't pull anything. Your joints are anywhere on your body that you can bend i.e. your elbow or knee,
stretch warm up meditate eat well plenty of sleep
Arm warmers are often worn by athletes that want to stay warm in the warming up period of their runs. The warmers are light enough to wear without the bulk of being a whole jacket and can be stored easily into a pocket when the runner is too warm.
It relaxes your muscles for the upcoming exercises.
pulse raiser, stretching and skill related warm up
You should warm up before a competitive event because you need to get the blood flowing and the muscles all warmed up And loose. Also it helps loosen any lactic acid build up or potential lactic acid.
An impact printer (dot matrix) is ready for use once switched on. A thermal printer (non-impact) may need a short warm up period.
Warm-up, training period, cool-down
WARM-UP
Warm it up until it liquifies. It will then stay liquid for weeks. It can be re-warmed if required.