What should a persons HR be while running a marathon in relation to their Tempo HR? For example a tempo run of 6 miles, yields a HR around 165. Should your HR be 165 for the marathon? Should it transition from say 145 to 165, getting high at the end (last 6 miles)?
Yes, your hr should be lower for the first few miles of a marathon than in an anaerobic threshold run, and if you are well trained and run an even pace, it will rise gradually (1 beat per min. per mile) until it is very high at the end. of course, if you bonk, you may end up shuffling in with a low heart rate.
Heart rate numbers are meaningless without knowing your max. If your max is, say, 190 or above, perhaps 165 might be reasonable for a marathon. If your max is 170, then 165 is too high.
And max numbers are meaningless unless you determine them via an actual stress test. Formulas based on your age or other factors are not useful.
I agree...You have to know what YOUR max. heart-rate is.
Ideally you want to stay in an aerobic state during the race, which means that you should try to stay below LT, that should be somewhere around 88% MHR.
I've read several articles that say that you shouldn't use a HRM during a race, as your heart-rate tends to be a bit elevated from the race-day excitement, and the numbers that produces may not be accurate.