What is long sleeve running shirts?
When talking about running shirts,mostly long sleeve tops, has the main functions:

quick dry, moisture control,soft,keep warm etc.

Its fabric including:brushed thermal knitted fabric,polyester/elastane,nylon,merino woll, etc.

Most people use running shirts in order to adjust climate change while doing workout indoor or outside.

So there is a double needs for booth keep warmth while it is cold and getting cool quickly while it is hot.

Have a look at what Yotex have produced: