I'm a newbie training for my first half IM in July. I did a pretty hard bike workout (3hrs+) on Sat then tried to do an EZ 20 minute run right after. Everything felt fine on the bike - HR was around 140 bpm. Problem was when I went to the run my HR went up to 164 bpm (normally this would be somewhere between a tempo and speed workout for me) and my pace was a barely a jog. After 20 minutes not much improvement. Not sure that I could have run 2 hours in this condition. Any advice? Can I expect some improvement as I add more Bricks? Thx!