Did my first true HIIT last night, apparently I was doing indurance intervals before. Anyway I hit the bike around 8:00 pm and hit the sack around 10:00 and layed there until 12:00 which is very unusual. Is this common or was I just wired? If this is going to be standard I'll HIIT in the morning. I leave the house at 6:30 already so I really don't want to get up at 5:00 if I can help it. I'm also a little nervous going from sleep to max HR in 5 minutes.