Effort and running speed

by Helen
(Copenhagen, Denmark)

Effort and running speed :

"Hi Marius, I have now been following your program since the spring and I just love the variations in the program but I have a question regarding the effortzone versus the speed.
In effort 1 ( puls 129 ) I run 6.22 min/km
In effort 2 ( puls 141 ) I run 6.02 min/km
In effort 3 ( puls 154 ) I run 5.18 min/km
In effort 4 ( puls 164 ) I run 4.50 min/km

My max puls is 183.

What I don´t understand is that I run too slow in effort 1+2 but run faster in effort 3+4 than what is says in the program for 4 hours. I WANT to run below 4 hours in 6 weeks in Berlin.
So how do I plan my marathon ? Should I run by speed or still by heartrate as I do right now and will I then be able to make it below 4 hours ?
Hope you can help me ! - Helen

Answer: Hi Helen, great question. Training by pace for a marathon is more inaccurate than heart rate. What you experience is common - one zone is "easier" for you compared with the average runner (that these paces are based on - sort of the median average) If usually has to do with your running economy being better at one pace vs. the other.

You should not worry. BUT, it is important that you use the half marathon scheduled to pace your marathon. If that time in the half marathon is close enough to an estimated time sub 4 hours then go for it. If not, you may want to start out a bit slower so that you don't risk hitting the wall.

Either way : stick to heart rate and do not worry about the difference in paces too much.

All the best,

regards,
Marius