Rode on the trainer today for 1 hour. I did a 30 minute interval @ 160+ HR for 18 miles. I did this last week as well but felt better today. Near the end of the interval I was able to maintain around 170 HR. David also rode on the trainer but couldn't get his HR up. I told him to back off and take it easy. He rode for 55 minutes for 7.77 miles.