Well depends on how much i want to run, that adjustment period i usually take for setting a deeper & slower breathing tempo which helps with energy during longe

Well depends on how much i want to run, that adjustment period i usually take for setting a deeper & slower breathing tempo which helps with energy during longer runs(i think some may call this trying to avoid 'negative energy' in endurance terms).I have the same reaction usually with colder temps: go faster->higher blood flow->feel less cold.I also do more breaks in summer,it's definitely worse.I guess my lower BMI & generally less time for recovery immediately after are the main reasons for these changes.