[Brian Bauer]

it is not unusual for me to discover in my data that in the later stages of a 2-3hr race I am moving much faster at the same HR.  if I kept the pace the same this would show a declining HR over time.  However, my intent is normally to remain at a Racing level of effort which results in greater speed not a reduced HR.  in my case this is caused by a lactic shuttle that improves over race duration