The way I track my marathon potential time is by adjusting actual runs where I use a heartrate monitor by the slope of the typical progressive runs heartrate vs pace curve – to my target marathon pace heartrate of 164 bpm – the slope typically is about 3 seconds per bpm – so for example a 6:30 average pace at a 162 average heartrate would indicate marathon pace potential of 6:24 (2 bpm x 3 seconds/bpm = 6 seconds faster).
1. Pre-Taper/End Training – the three datapoints shown all came from progressive runs within a month prior to the marathon. Basically I draw a line thru the HR vs Pace data in the progressive run and where the line crosses 164 – I call that the marathon pace potential point. The last couple were done actually during the depletion part of my taper but at that point there did not seem to be any speed degradation from this depletion. 6:13 pace was the fastest data point. Weight prior to depletion was ~153ish.
2. End of Depletion - Towards the tail end of the depletion part (10 days of minimal Carbs in my diet) – my speed was suffering. I did a few short MP paced runs 7, 5 and 4 days out from the marathon and struggled to maintain a 7 minute per mile pace at MP heartrate. Lowest morning weight I saw toward the end of depletion was 147ish.
3. Start of Loading - Three days pre-race (Thursday) I switched to a minimum protein/fat diet and after a day of carbs went running in the evening – a very short workout with a 6:10 potential measured off just a few Marathon Paced miles. I did this run about 2 hours after a big dinner and think it would have been a bit faster later as digesting food has a way of adding a couple bpm to the heartrate.
4. Race –
First miles were run pretty much exactly at the heartrate target however started slower around 6:20 pace and gradually got faster to around 5:55 pace. I’ve seen this speeding up for first 10k or so in about every marathon I’ve run but I do NOT typically see this in training runs. I think what is going on here is pre-marathons I have always done a very large carb-loading in the final hours before the race and the body is still in digesting mode for the first 30 minutes or so of the race. I have been wondering if I can eliminate this morning loading and eliminate this slower first part of the race – but I’d hate to find the regret of running out of gas at the end of the race. I’m thinking about 20 seconds per mile is lost first 6 miles so ~2 minutes of opportunity if I can cut out the digesting energy expended. Right now I’m thinking I’ll take a measured step here and cut my pre-race load in half for Boston and see how that goes. Unfortunately I can think of no real way to experiment with this except in a race since the question is will I run out of gas at the end.
Middle Miles since I did run these miles way off the 164 – especially after mile 16 – I was able to compare a pretty good amount of data around 158 bpm to the 164 bpm and it looked like 3 bpm/second was a little high – so I only adjusted the theoretical pace about 2.5 seconds/bpm off 164 bpm. I have some doubts I could have maintained 164 the whole race had I pushed for it as the heartrate vs pace correlation really fell apart at the end – the last mile really has me scratching my head.
Last mile (actually ~1.5 miles) I had in my mind to push the heartrate up over 160 vs the high 150s I’d been running since mile 16ish. I ended up averaging about 161 bpm and from that somehow plowing out a monster 5:32 pace average over the last 1.5 miles. It was like the heart just wouldn’t beat any faster no matter how fast I wanted to run. I originally figured the buildings at the end were just screwing up the pace data that is based on GPS data so I went back and verified the distance from where the GPS data was good and measuring the distance off the map and the 5:32 pace is off my measurements – not the watch – although they happen to be pretty close – and the heartrate data looks steady – not bouncing around like it’s bad data – so I’m thinking the data quality is good. So corrected to the 164 bpm with 2.5 seconds/mile is where it is plotted at 5:26 mpm on the graph.
So this all leaves me thinking I cannot run at 164 bpm to the end because I would apparently be speeding up to 5:30 minutes per mile if I did basis that last mile – I’d like to believe I can do that – in fact thinking back on that last 1.5 miles – I didn’t know how fast I was running - it seemed to feel like I was running at a marathon pace – not Tempo or faster - while the miles prior where I was running in the high 150s had the feel akin to a long run pace which makes me wonder if I really can hold that increasing mile by mile pace to the end – but realistically – I just have trouble believing I can run that fast. Very interesting last data point on that race and it really has me scratching my head and wondering if maybe I can go that fast.
Btw – weight at the race was around 150ish as I’d added a few in the carb/hydrating 3 days up to the race.
Deplete/Load Benefit It is always hard to correlate individual variables but I can come up with nothing else that explains the ~6-7 minute drop in marathon time from the pre-taper data points and the race day capability. I've heard this deplete/load thing now called the Sultin Diet apprently created by a Cross Country Skiing Team back in the 70s although I haven't been able to locate any literature on it. I'm really currious why it works - I was thinking weight loss or maximizing the glycogin loading into the body's storage locations (muscles/liver) - but it still seems there is a missing piece as loading shouldn't in my mind give extra speed - just endurance - and I'm lighter now yet slower. I'm thinking it must somehow cause improved oxygen delivery - I wonder if red-bloodcell count somehow goes up during this depletion phase - I have read that some (illegal) drugs can do this and have similar impact in endurance sports to what I saw so I'm wondering if the deplete/load somehow does something similar. If anyone has any pointers to studies on this stuff I'm real interested in reading.
Letsrun response to this question
5. Recovery - I have been tracking recovery since the race. Up until yesterday (somewhat at the 5k) I have not really been pushing my workouts letting recovery happen but I still had a few workouts with the heartrate monitor hard enough that I could project my marathon pace. I was a bit surprised how slow it was at first but it is nice to see it coming back down to near where it was pre-taper. And should you think I got slower because I’ve been adding back the pounds – this morning I weighed in at 147ish – so even lighter than race day – but not near as fast.
Last nights run was a progressive run and it felt fantastic to push it to the end. I plan to really start ramping up the quality/quantity here on out getting ready for a faster Boston.
John.
6 comments:
I found these a year ago and they have become my mantra:
AMPK is activated by any stress that inhibits ATP production or increases ATP consumption. This includes hypoxia, heat shock, exercise, and glucose deprivation. AMPK is also activated by the hormones leptin and adiponectin. As its name suggests, AMP directly activates AMPK.
I also reference this pdf occassionally as a reminder: http://www.physoc.org/publications/pn/subjectcollections/pncollectionspdfs/Skeletalmuscleexercise/2004/Wackerhage.PDF
I would never be so bold as to try a 10 day depletion - but, now I'll definitely attempt it. It almost seems like you stimulated AMPK in the same way that altitude (hypoxia) does. And, much like 3 days at altitude doesn't seem to have *too* much of an effect, I think the 10 days seems to really force the body to make changes (based on what I've read, it seems like mitochondria has some sort of 3 day cycle - see http://www.letsrun.com/forum/flat_read.php?board=1&id=271683&thread=269985). However, much like with everything, I'm wondering when the law of diminishing returns start to kick in? Is "10 days" optimal? Awesome stuff.
Re-reading your blogs and training, it really is quite the wonder - what an amazing mystery/puzzle! However, I would take off another minute or 2 for improvement from NYC because of the "hometown" and familiarity factor. You flew in the day/night before for NYC!
Inside the Black Box (PDF)
That link didn't paste very well.
kanny - thanks for the info - I think I need a PHD to understand even half of the letsrun thread :D. I read most of the info and scanned some.
Probably take some soak time and reread to really get a reasonable fraction of understanding from this but I think the message I gather is that the deplete may have caused a stress on the muscles similar to a couple weeks of altitude training that caused a response of increasing mitochondiral activity which in turn enabled a higher effecent energy production for use in the race.
This exersize physiology stuff is interesting and confusing - like I said - I think I need to reread a few times.
Thanks again for posting the info.
and I do think the home-field advantage helps explain NYC to Houston differences - not so much training runs to race day differences although they can be explained somewhat by the taper (less fatigue at the race).
I'm treading dangerous water when I compare it to altitude, though, because it's pretty established that it's the body's ability to increase hemoglobin/red blood cells (the whole natural EPO thing) that is the benefit of altitude. Then again, I feel like that's just scratching the surface. There's so much more to the adaptation than I can imagine. Thinking about it all simulates altitude dizzyness.
I understood the corrilation to altitude training to be a stretch - all the theories are a stretch. Summarizing to theories to date:
1) Weight loss from 10 day atkins diet gave extra speed.
2) Extra Abondance of Glycogen from deplete/load caused lower fat burn requirement and thus lower oxygen requirement and therefore lower heartrate (oxygen delivery).
3) AMPK activation by the deplete caused greater mitocondrial density again reducing oxygen requirement.
4) Deplete/load stimulated higher redbloodcell count (oxygen carriers) enabling higher oxygen delivery for lower heartrate.
5) Just had a good day in a familiar low stress environment with low fatigue from a good taper.
I am tending to lean toward combo 1,5 answers but whatever the reason you can bet I will be trying to duplicate this again in Boston.
kanny - you've really turned on an interesting line of research. Amazing all the things that come up on google for - Activation AMPK carb deplete.
One article I came across make me think that exersizing at a fully depleted glucose state is like focused training specific to what it is like at the end of the marathon when the glucose is depleted - by stressing the body in this state the body adapts to better handle this state - I guess by increasing mitochondiral density - fascinating stuff.
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