Racing in IM FL for the first time with a power meter.
What do other experienced athletes using power meters, like displayed on their screen while racing. I'm thinking: 3s Power watts, distance, speed, average speed, heart rate, time elapsed? Some have also suggested an auto-lap every 2 miles, for 3s power average? I'm racing IM FL in two weeks and would appreciate any feedback, thanks! 
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My $.02... real-time power (1 sec) and HR are the only critical metrics.
Cadence is a nice to have, but you should be pretty good to figure out if you are mashing or spinning out, just by feel.
My interpretation of the EN kool-aid is: figure out your capability in training, then calculate target power ranges for YOUR race and stick to them. Make adjustments for weather, good day/bad day. All the rest makes for interesting after analysis and statistics.
YMMV, Joe
1 second power is what i pace off of
Speed let's me know when to stop pedaling on a downhill (over 34mph)
Cadence keeps me from dropping my cadence to keep up watts, which I tend to do unconsciously
Everything else is gravy. Of course, having real time is a big plus, since I drink my infint every 15 minutes. Almost really goofed that up at LP this year...
I'd use 1s power, HR, and time.
I only keep actual speed on the dial on hilly courses, and this is to tell me when I get to faster than ~32 mph on a descent, and it's time to slack off and coast. I don't remember too many descents in FL, so I think the race execution value of that piece of information is lost.
HR is in my back pocket in case of some radically different course or race day characteristics - heat, humidity, hail, rain, Act of God. Otherwise, I scroll to it on my yellow PT once or twice per race, and mainly to break the boredom. Absent course or race day characteristics, you've done the work, done the RRs, and are just following your watts. No drama, so no surprises.
Time is only for "switch from Gear 1 to Gear 2 at 30 minutes," and to tell me to eat every 15 minutes. In fact, I try not to look at my elapsed ride time anymore ... as much as I hate this saying, it is what it is. Moreover, not looking at the elapsed ride time has probably stopped me from making serious execution errors trying to chase a sub-5 ride or hit a goal bike split. Still a long day out there.
I don't see the need for HR on the bike if you have a power meter. Your HR is a slave to a hundred different variables. Your power is not.
Barb, I have power, cadence and time on my PT. HR can be scrolled. Speed is not relevant in the EN world. Speed is totally subject to course difficulty and wind. Stick to your power numbers based on your FTP and what Coach RnP tell you related to execution. Florida is a flat course however the back 37 mile stretch has rollers and if windy you will have a head wind and can be deceivingly difficult. Therefore speed is not relevant and neither is cadence if you have been training in accordance with EN koolaid principles. You will know if you are mashing your gears or spinning too much to maintain your watts. Also, be prepared for the last 6 or so miles of the bike leg, it will be a head wind. Be sure to go to the EN pre race talk, Coach RnP will give execution guidance for the course. Listen to what they say and execute it well. You have been training hard, reading the feedback on the forums and you are ready. Its about execution not fitness, stay in your box, focus on the present and remember the one thing that will pull you through the last 6 miles. Nothing matters until mile 18 of the run..........have fun and embrace the moment. Cheers, Greg
Speed
Time (I interval it out every hour)
Screen 1:
Power (Large)
Speed | 3s Avg Power
Distance | Cadence
Screen 2:
Elapsed Time (Large)
Speed | Distance
Time of Day | % Grade
I usually just look at Power and try to keep that number steady, if someone asks how fast I was going on a particular section I usually reply with something along the lines of "190 watts"
The reason why HR is important for IM is because I have yet to find someone who can maintain an elevated HR for over 8hrs. 4-5hrs is no problem for most but IM is a different beast. If your HR is relatively high, for whatever reason, you will have to back down eventually or your body will force you to back down and then it usually gets ugly at that point. On many more than one occassion I've seen someone ride a power number into a brick wall because they ignored their HR.
Also, although I often describe to people the speed at which I think you should start coasting, I simply recommend coasting when you run out of gears. For me that's usually around 37mph but different gearing will dictate. I highly doubt this is an issue at IMFL anyway.
Thanks, Chris
If people ride a power number into a brick wall it's because they haven't trained properly... at all. If you know your FTP, the 70% rule for IM pacing (+ or - 2% or so depending on the person) is pretty well established. You should have trained several long bike rides at that number. If that person goes out and attempts to ride 112 miles at 85% than they deserve whatever happens to them. People are their own worst enemy. We will do our best to try and side step common sense and established physiology whenever we get the opportunity.
I'm not saying that HR isn't a nice metric to use, especially when combined with a power meter. It's just not the best metric to use solely on the bike. I can see it's "backup" ability and applicability though. There are just far too many variables that dictate HR which makes it somewhat unreliable to me:
- What's the temperature outside?
- How much did I sleep?
- What did I eat?
- How hydrated am I?
All important factors but have zippity-do-da to do with your true work effort.
To quote Dr. Coggan and Hunter Allen:
"Your heart rate may be affected by factors that have little to do with actual performance, however, and using only a heart rate monitor could easily trick you into believing a false conclusion about your fitness, mislead you about your performance, or even undermine your confidence."
I'm going to point out where I believe you're making some fairly substantial fundamental mistakes:
1. Obviously we're speaking in relative terms. So, NO, I have never seen a single athlete (pro or otherwise) maintain a relatively high HR for an entire IM. Not once. Although, we could probably argue about the definition of "high" (even in relative terms) so I'll give you an example:
I do the IM bike between 150 - 155bpm. Even if my power target is dead on, if I try to maintain an HR closer to 160bpm throughout the bike due to something like hot conditions and go into the run expecting to do 75-80% of T pace, depending on course and conditions, then I'm done probably around mle 18 or so. So, 160bpm on the bike in this specific example is considered "high."
Now I wouldn't be surprised if some random pros or very gifted AGers have managed to pull if off though. However, we're talking about a very small minority. And never go into an IM thinking you're special on this day.
2. Honestly, the fact that you don't believe you can ride an appropriate power number (eg, IF = .70 - .74) into a brick wall tells me you have a fair amount of inexperience with a PM. Sorry if that sounds harsh but my extensive experience in this sport which involves 7 years of training and racing with a PM and spending countless hours working with other athletes and coaches says you are dead wrong. I've done it myself. I rode IF = .73 for the first 80 miles at IMC last year. I've ridden .74 more than one time at IM in the past too. In this same year I also managed to do at least 3 x 6hr long rides all above .77 where I could have easily run off the bike. I did many other ~5hr long rides too (all >.75). As a matter of fact, it was the most perfect training year I have ever had in my prep for 13 IMs. Funny enough, it just happened to be the only year I didn't qualify for Kona (except my first year). Training only dictates your preparation, it does not dictate how smart you will race.
3. If you screw up any of those variables you mentioned above (eg hydration) or it's a hot day, you will have to slow down. This is exactly why HR is important. Most people actually don't necessarily realize when they get too dehydrated and HR will tell you that. HR is an indicator of a component of "true effort." That component is cardiac strain.
4. If you know me you know that I'm a fan of Dr. Coggan but he knows jack shit about doing IM (and has readily admitted that to me on many occassions). There's a reason why he never challenges me when I talk about the importance of HR for IM on a forum.
Now keep in mind that I'm not speaking from inexperience here. I've probably looked at more power and HR data from athletes ranging from MOPers to pros than 99% of the athletes/coaches out there.
I only suggest you race without HR if you have extensive experience in this sport. Keep in mind that even some coaches like Brett Sutton and Mitch Gold are training their athletes to ride below a specific cadence because of their concerns about HR in IM. In my very strong opinion, to ignore it is pure ignorance.
Thanks, Chris
Trust me, there's nothing special about me on any day.
I think we got signals crossed on one aspect - I'm referring to the use of a HRM on the bike and I'm not cursing its use overall. I do use it on the run and most definitely will for IMFL. Therefore, I can monitor (pun) my HR there so that it doesn't get too high and I can reel it in if needed. If I had a power meter in my legs, I'd abandon using a HRM there too.
I was also referring to the use of it on the bike. Here's an issue I've seen on many occassions:
When most of us are running to our full potential, our HR is about 5 - 10bpm higher than what we maintained on the bike. So, riding with a relatively high HR on the bike can become a problem on the run because your HR will want to rise accordingly. For example, if I'm riding in the high 150s on the bike then it's very possible I will see mid 160s on the run (asumming I'm running well). For someone who can normally ride in the low 150s on the bike at an IF in low the .70s and run in the high 150s to low 160s at E pace, it's a tall order to expect them to maintain the same power and pace with an HR that's 5-8bpm higher. It just doesn't happen in my experience. You're much better off slowing down on the bike and getting your HR in control with the potential of getting back to target power and pace later on as opposed to taking a significant risk by trying to maintain the high HR for the remainder of the race.
You need to consider the cumulative effect of racing with a relatively high HR as the race progresses. Most people just don't have the physioloigcal resources to maintain that level of cardiac stress for that period of time. Again, it's one thing to do it for around 4hrs but it's another thing to expect to do it for much of the IM bike and run.
Thanks, Chris
Chris- thanks for your insight as well. In the past I've put HR on the "second" screen of my computer and only used it as a troubleshooting tool. But when I think back to my problems at IMWI this past year, I know the issues actually started much earlier on the bike and I don't think I ever switched that monitor screen to check in on how the HR was going. And to be even more frank, even if I had, the reality is I hadn't been looking at HR much during training so I'm not sure I would have know what to expect on that screen anyway. Stupid. My power numbers were dialed in, but I was getting dehydrated (and very low on cals) and I failed to recognize the signs. Perhaps if I were more in tune with where my HR should be/was at the moment I could have recognized a problem earlier and done something about it.
I hope I didn't give people the impression that HR is more important than power. I figured a lot of people know my position on racing with RPE, power and HR at this point given how much I've discussed it on forums, papers, etc. However, that might not be the case so here's the link to my article which discusses this issue in gruesome detail:
http://chris-lakerfan.blogspot.com/2010/04/im-bike-execution-using-rpe-power-and.html
I view HR as a tertiary metric/indicator. The simple breakdown is the following:
If RPE is high but power and HR are good then back down
If RPE and HR are good but power is high then back down
If RPE and power are good but HR is high then it becomes more complicated and you have to make a very calculated decision. Examples: 1) If you're just coming out of T1 then that's normal so just give it some time and it will likely come down after about 10 - 20min. 2) If it's 3hrs into the bike and you're possibly too dehydrated then drink up and see if that fixes the problem. 3) Etc...
Btw, I always ignore a low RPE.
For the run I consider pace, RPE and HR (in that order). As opposed to the bike where I will back down due to a high RPE even if I'm at target power and HR, I won't necessarily do the same on the run because l often feel like shit coming off the bike and won't really find my rhythm until about mile 4 or so. In addition, there are often periods where I'm not feeling well on the run and it's a simple matter of taking some extra fluids and calories at the next aid station to remedy that situation.
One more thing... HR is also highly misunderstood, imho. I'm always amazed at how poorly people understand their own HR characteristics and what influences high or low HRs.
For example, I find that many people think that the low HR they often encounter during peak training hours toward the end of a race prep period is due to an increase in fitness when in fact it's more likely due to fatigue.
Thanks, Chris
As a follow-up to my first post @ racing with power.... , I really appreciate all the reply's. I will treat HR with much more respect now, to use as a gauge while racing. There have been times during my training I have ignored a high RPE, even if power & HR have been in normal ranges. I never would have been able to race 112 miles with that high of RPE, but may have tried to anyway? I'm still learning all this, but still would like to minimize any mistakes before my race! Thanks EN members for your insight