When I ran I used Skins compression tights for all races and workouts in the winter. I also used their half tights (shorts!) during the summer with a pair of compression socks. I found it helped warm me up and although anecdotal I seemed to have less issues with calf strains when I used them. For TT I use to use Nopinz calf guards which have some compression - now I use Castelli fast feet which are long but not really compressive. I don’t find it makes any difference either way. That said of course my Nopinz flow suit I race in is very compressive I have to take a very deep breath to get into it! 