Rracing the run via HR rather than pace
Still quite new at running after swimming and biking...
And I'm not a very good writer either but I thought that I would throw this out there for public scrutiny.
I raced my first 70.3 as a member of EN at Mt Tremblant a couple of months ago. I still biked too hard even after all of the warnings to the contrary. On the run, I tried to hit the Rx'd paces for miles 1-3 but it was clear by mile 2 that it was not going to happen. I held on to the MP+30 Rx'd from my VDot for as long as I could. But by the last 1/3 of the race I was beat up and jog/hobbled in.
1 power meter later, I am working to put out a better race in Austin in about 10 weeks. I am confident that better bike execution will lead to a faster run and a better overall race.
Mt. Tremblant has led me to review other runs that did not work out the way that I had hoped to see if there were any common traits.
I have dug through the data streams from longer runs and races (including a couple of 70.3 runs and a few stand alone marathons) trying to find cues between the "successful" runs and the "unsuccessful" runs. With successful defined as maintaining goal pace throughout and unsuccessful defined as falling off towards the end of the race.
One thing that jumps out at me - In all of the races where I popped and had to walk my HR got close to LTHR early. In Mt Tremblant for example, I was at LTHR 20 minutes into a run that ended up taking 2:15. I would run for 8 or 10 minutes at LTHR and then have to walk for a minute to calm down. I didn't know it at the time because I was only watching pace.
I know that training and racing by pace is the preferred method at EN. But I am curious to know if anyone else sees a correlation in their racing between elevated HR and needing to slow down.
Also, I wonder about the wisdom of racing the 70.3 run primarily by HR. Especially early on. I know that I can run for hours with my HR in the 150's. But once it gets north of 165, I seem to be on borrowed time, regardless of how fast that 165bpm is moving my body down the road.
I guess that the ultimate prooving ground should be the race rehearsal. In my race rehearsal for Mt. T, I was just fine at MP+30. But by the time my HR crept up to 165 bpm, I only had 23 minutes left in the run. I was able to hold pace for the first 3mi and then speed up in the next 3 as Rx'd. But doing so ramped my HR up to and past LTHR but the time it was over. So while it was a "successful" RR in terms of hitting target pace it was NOT in hind sight a predictor of being able to hold it together for the next 7.1mi of the run.
I know that this is a ramble. I think that what I am trying to say is that I need to keep an eye on my HR during races. I need to keep a lid on effort and not let it approach LTHR till I am in the last 30min of the run. Or something like that.
Thx as always for your insights. Lots of really fast people here. Luckily, there is no minimum Vdot to join!
Comments
However, in race situations (@ 13.1 or 26.2), I always use HR as a govonor to Pace to prevent me from running the wheels off the bus. IOW - my race plan would be based on Pace but depending on heat, humidity, dehydration, fatigue, etc if my HR gets above 172 I have to back down because I know that above that, I only have 25 to 30 minutes before I pop. But at about 166 or less, I know I can gut out 2 hours or more. My LTHR is 179
In the end it comes down to how much can you suffer and still maintian the goal pace? At what point does the HR indicate you're heading full steam into a brick wall? If you know those things, HR can be a valuable tool when applied to Pace.
@ Steve - That is exactly what I am talking about (or fumbling towards.). My LTHR is 171. Once I hit 165, (about 96% of LTHR) I better be about 30 minutes from the finish line or I am going to be in trouble if I keep my HR there. This general assertion seems to be true regardless of weather and regardless of pace.
I think that I would like to try using HR as a govenor in longer races. I figure that if I am more than 30 min from the finish line that I am going to limit HR to 160 and see how that goes. I have a RR in 10 days. I will try it out then. I guess the question at the end of the 6mi run will be "could I do 7.1 more?" rather than turning it in to a 56mi bike at target watts and a 6mi race.
@Scott - Weather is a big deal. Esp where we live. I am hoping that a HR govenor will eliminate the need to do the pacing math. Austin in October could be 85 and it could be 100. If it is 100, then I will need to slow down but my hypothesis is that my heart rate will tell me to slow down as well.
Thanks yall for taking the time.
Remember that one problem with HR is that it fluctuates from day-to-day and also in heat. On the flip side, HR acts like a powermeter in that it tell you about your physical exertion regardless of the headwind/tailwind and uphill/downhill.
So for training, I will use pace any day of the week. The lap average pace on my Garmin is a whip on tough days to make sure I'm nailing those mile repeats. But in racing, you are right that you don't want to get to an HR where you are 'on the clock' too early in your race. And despite day-to-day variations in HR, those of us who analyze our data pretty well know what that HR is. For me I call it "high 170's / low 180's". I'm deliberately imprecise because of the day-to-day variations, the impact of heat, etc.
All that said, for the amount of training we all do, I think you really can't argue with RPE. Most people don't have a good sense for RPE, but if you have done a few years of training and have a lot of experience with the relationships between pace, HR and RPE, you really ought to have a good sense for what is going on during the run regardless of your Garmin. I can guess my HR to within 5bpm no problem when running. I'm not as good with pace, but I can certainly get close enough.
I think the combination of these things can be used to manage your run. Personally I use RPE and pace, and don't show HR on my Garmin. But I am planning to experiment with some HR targeting ideas going forward and may change this (one in particular is using HR to allow faster pacing coming out of T2...i.e. allow yourself to run your HR into that steady race-pace zone quite quickly). Overall I'm a bit concerned to "cap" HR in a very mechanistic way...some days you have a good day and can sustain more. And some days your HR is just higher or lower. And in a race environment some people can simply perofrm at a higher level. On the bike I see the argument for capping power because it is very hard to use RPE when you're trying to meter your effort in order to set yourself up for a strong run (but HR is relevant to monitor because when I see decoupling I know I'm in trouble). But on the run I really think a well-calibrated RPE is difficult to argue with.
Btw, a separate issue, where I find this gets really tricky is when muscular enduance becomes the limiter. I.e. the opposite of the situation you're describing...this is when your legs get too tired, and both your HR and pace drops. In that case I really think you need to focus on pace as a whip.
I would like to offer my theory as to why HR matters, and why one might want to use it as a rein the longer the race.
My belief is that for HIM and IM, the run is long enough that it is rrelatively easy to get behind on both hydration and calories to the point where one can no longer run, or last can no longer run at the desired pace. The primary purpose,IMO, of following pacing and HR guidelines is to ensure sufficient blood flow to the gut to absorb sufficient fluid and sugar so the muscles can get the fuel they need to keep contracting.
IOW, the higher the HR, the more blood is being shunted to the muscles away from the gut, decreasing the ability of the gut to transfer fluid and fuel into the bloodstream. There's no magic cut-off, it's obviously a continuum. I suspect walking in the aid stations after drinkoing also helps here by lowering the HR temporarily to allow more rapid, complete absorption. Heat also makes a difference as the body will shunt more blood to the skin, again away from the gut, to aid in cooling.
So,you could help the whole process by making sure you get enough fluid and fuel during the bike, and by going slower at the start of the run while "tanking up" when you can.
Train and race with HR enough,and do enough training runs and races to occasionally flame out/bonk, and you eventually learn what the right effort level feels like, so RPE can be useful.Until then, it's OK to use HR to keep within your body's limits to fuel and cool yourself.
My suggestions for the absolute upper limits for HR for an IM is 78% of max HR. Less experienced athletes might want to keep below 75%. for an HIM there is more margin for error (you may have up to two hours of fuel on board at the start of the run); for me, the max there is 85% of max HR. That said, I no longer train or race with HR,although I do observe it on occasion during some WKOs and rare races.
I am going to give this a try in the oly and 70.3 that I have left this year. For the Oly I figure high z3 till the last 20min then let it rip. For the 70.3 upper z2 drifting into z3 as the race goes on.