Analyzing the "Fast finish long run"

Today I downloaded my last workouts from Polar watch to computer so I can analyze them now. As I told in previous post I had some thoughts based on how I felt during the workout. But the data itself had some surprises...

As a short recap, the "Fast finish long run" was composed out of three working sections + warm up/cool down:

1. Warm up (blue zone) - 10 min
2. Green zone - 20 min
3. Green zone at marathon pace - 30 min
4. "Run hard" Yellow zone - 10 min
5. Cool down (blue zone) - 10 min

The interesting parts are marathon pace and yellow zones: they should tell me how fast can I run. During the training I felt that "marathon pace" was just a bit too fast to keep it for the whole marathon distance; and the yellow zone was getting me to the edge - those 10 minutes was almost maximum time I was able to keep on. At the same time I was believing that pace in yellow was only a bit quicker than in marathon pace: 4:35 vs 4:50 min/km or so. But now let's take a look at data itself:

For the 30 minutes at marathon pace the recorded values are following:

• Heart Rate (Average/min/max) 168/157/174 bpm
• Pace (Average/min/max) 4:48/5:33/4:15 min/km
• Distance 6.2 km

That's almost exactly as I expected. I also looked at shorter sections at the same phase,
last 20 minutes at marathon pace:

• Heart Rate (Average/min/max) 169/165/174 bpm
• Pace (Average/min/max) 4:43/5:18/4:15 min/km
• Distance 4.2 km  

And just a last 10 minutes from same section:

• Heart Rate (Average/min/max) 170/167/174 bpm
• Pace (Average/min/max) 4:43/5:18/4:15 min/km
• Distance 2.1 km 

(BTW, when I divide time with distance, I get a bit different average pace numbers:4:50, 4:46 and 4:46. Maybe the distances have some rounding errors...)

Now the same data for yellow zone:to everyone

• Heart Rate (Average/min/max) 180/174/183 bpm
• Pace (Average/min/max) 4:17/4:43/4:01 min/km
• Distance 2.3 km

And here comes the surprise part: The average pace was almost 20 sec/km quicker than I was thinking. And it invalidates my thinking that there's not much point push harder: the speed gain is actually significant.

But it actually does not change the HR limits for marathon race: As I felt "a little over the border" during the "marathon pace" zone and it had average 170 then it seems to be the border line for long period effort. I.e. if I keep my HR couple of beats below it I should be in safe range. And there is a general suggestion to start with low intensity, in order to allow body to start fat metabolism processes correctly. The first 10km should be below 165 bpm. Or is it too much?

I wonder what else should I look at when analyzing the the trainings? The stuff I'm doing here seems to be really basic...

I also felt I got confirmation for  my target HR limits from green "Marathon pace" run on Wednesday. It contained 25 min of green run in marathon pace:

• Heart Rate (Average/min/max) 166/148/173 bpm
• Pace (Average/min/max) 4:50/5:42/4:20 min/km
• Distance 5.1 km

It felt a little bit too hard. So keeping HR during 10km below 165 seems do be a wise decision. After that I will see if increasing to 170 feels Ok or not... Knowing myself it will be hard to resist going too fast.

So there's less than 38 left till race... Weather forecast is excellent: no rain, variable clouds, very little wind (less than 2 m/s), temperature between 13 and 16 C. I hope it will be nice run on Sunday. Good luck to everyone taking part this event, or any other events taking place around the world!