Help me understand bike split at Muncie

steve Beyer

I'm at a loss to understand what happened...physiologically...on the bike this past weekend at Muncie and would like input/help so I can be smarter and improve.

Short summary: Had fastest 56 miler ever...both time and mph avg....(races and RR's included), with the LOWEST NP ever, but at a much HIGHER heart rate.

Here is race and RR results of last two years, starting with most recent (Muncie last weekend), and going backwards:

7-11-15(Race) 2:30:40, 22.3mph, 210NP, 1.01VI, avg. HR 152...IF .79

6-27-15(RR#2)   2:39:21, 21.1mph, 224NP, 1.01VI, avg. HR 142...IF .84

5-30-15(RR#1)   2:45:14, 20.3mph, 223NP, 1.01VI, avg. HR 146...IF .83

* Was more overcast/cool for RR's than at race, but not a lot...weather for Muncie was really pretty nice.

 

For comparison, and to see how consistent I was (until Muncie), last year was:

7-26-14(race) 2:35;00, 21.7mph, 217NP, 1.01VI, IF.86 * wasn't at Muncie, and VERY hot/muggy day so dialed watts back at end

7-12-14(RR#2) 2:33:25, 22.0mph, 222NP, 1.01VI, IF.87 * testing between 1st and 2nd RR showed drop in FTP

6-14-14(RR#1) 2:45:54, 20.4mph, 232NP, 1.01VI, IF.84 * run afterwards proved went too hard

 

In both years the 1st RR is without race helmet/wheels, whereas I go full race day gear for the 2nd. And unfortunately don't have HR data from 2014 as I wasn't using it

Now as far as how I felt on the bike at Muncie? HR was UP from the get -go (mid 150's), at around only 200 watts, sometimes even less. Thought it was just from swim and T1 excitement, but it just WOULDN'T come down. And the RPE at the lower watts felt consistent with the HR....ie.it felt like a 220-225 watt effort. Even worse....a HR of mid 150's is more like a Z4 effort for me. This non-sense kept up for about an hour, when I started being able to get the watts around goal level(220-225), but still at the low to mid 150 HR! The whole bike leg was a constant balancing act between HR not any higher, and watts not too pathetically low. Then the kicker is, even at that all-time low NP, I had my quickest(both time and mph) bike split.....doesn't make sense to me. And BTW, I kept wondering if I was going to pay a price on the run....well the first half was at 8:16/mile(right on target). Then the wheels came off about mile 7, and the 2nd half was at 9:39/mile. So my goal sub 1:50:00 run split turned into a painful 1:57:33.....while both RR's were from the 8:08/mile to 8:20/mile pace

 

Any thoughts appreciated.

 

 

rlh2000

Some of my non-wicked smart thoughts:
1) HR is VERY variable. Sleep, caffeine, all that comes in to play. And the difference between your RR#1 HR and race HR to me doesn't seem outside of measurement error/normal fluctuation.
2) How much admin time (lights, etc) do you have on a normal RR ride? All those add up a lot to change your average pace and potentially lower HR with little rest breaks.
3) I would put more weight into the fact that your RPE was higher than normal as well as HR rather than just the high HR. I think with both a high RPE and HR, slowing down would be key, rather than sticking to watts that you "should" be able to do. Why that happened that day, who knows. I think I remember reading that at IM Texas, Coach P couldn't hit his goal watts with HR staying in check (hope I'm not making that up). The fact that the run went south also seems like HR might have been telling the true story and watts needed to be ignored a bit.
4) Yes, swimming way spikes the HR to start, and would cause an average higher than normal HR overall compared to RR without the swim right before.

I'm very early in the learning process of how to listen to both HR and power, especially when they might be telling you different things, so thanks for sharing your experience and looking forward to what other folks chime in with.

Rich Stanbaugh

Hi Steve - I'm not sure if this helps, but here is a different view of the data you shared. First, looking at the power data and focusing on the rides at Muncie since they were on the same course...

1. Power meters are not perfect. On mine, the Accuracy is 0.1% and the Precision is ±2%. Assuming that yours is similar, and that you had the same power meter both years and that the accuracy hasn't changed, we still need to consider the precision of the device. This year's NP of 210 is really 210 ± 4 and last year's 217 is really 217 ± 4
2. Both years, your VI is phenomenal at 1.01 (think of this as 1.005 - 1014 that gets rounded to 1.01). I am interested in your Pavg, since Pavg is the "real" work that moves you down the road (and NP is a "model" of the metabolic cost of that Pavg). Pavg = NP/VI:  Based on the rounding of your VI, this year Pavg ≈ 207-209, and last year Pavg ≈ 214-216.
3. Now add the uncertainty related to your power meter's precision and this year Pavg ≈ 203 - 213 and last year Pavg ≈ 210 - 220. From this perspective, these two rides are pretty close to the same.
4. You didn't post the measured distance of the rides. A small difference in distance can also contribute to the different times. I would look at the distances to see how the ride length contributes to different times.
5. Weather differences (wind, air density, temperature) also will have an impact on the NP from one race to the next.
6. Even though the course is the same, differences in the road surface from one year to the next can contribute to differences in rolling resistance / NP from one year to the next. There is a section of rode on one of my routes that is freshly chip sealed... speeds are down / power is up on that section of road.
7. It looks like this year your FTP is set to ≈ 266 (FTP = NP/IF = 210/0.79) and last year it was set to ≈ 252 (217/0.86). The different FTP settings goes a long way towards explaining the different IFs. Having a higher FTP setting will lead to riding at a lower IF for the same average power output.
8. Your HR does seem higher than your other rides this year. My race HRs tend to want to be higher than my RR HRs and I have to work to get them down, especially when I first get on the bike or I first start running. In general, there are tons of different factors that can affect HR. It is an important metric that I monitor... but it can be suspect for me.

Based on the power numbers from the two races, they look pretty similar to me.

Regardless of the numbers - it was a really strong ride. Looks like it was overcooked based on the run. Why don't you look at what your Pavg really was for the races this year and last year (and your RRs)... if your Garmin doesn't show it at 207-209 this year, then something isn't adding up. If your FTP is not ≈ 266, double check what your device is set to, because IF and TSS will be reported incorrectly if the FTP isn't set correctly. These could lead you to mistakingly overcooking the bike.

steve Beyer

Rachel and Stan, thanks for your input. FWIW, here's what really stands out:

Rachel: "Early in the process of how to listen to both HR and power".....Yep, I can relate!! BTW, very low admin time on my RR's. Sleep was less, but don't know if it can totally account for difference. No caffeine intake ever.

Stan: Very interesting info. on PM accuracy/precision etc....thanks! Yea, if there is one thing I know how to do, that's ride steady (My Pavg for all my HIM RR's and races has been 2 watts below my NP). Difference in distance of rides was very minor (RR's were 55.9 something....actually a hair shorter than Muncie). The only real difference in weather was that for the RR's in was more humid, don't know if that jives...especially since HR was higher at Muncie.

Thanks for the input. Looks like this is just another one of those things that keeps it interesting. I did shout out to coach P in the Micro with a link to this thread, so looking forward to his input.

John Bayone

Steve,
When you did your RR's, did you swim directly before?
Meaning did you start your RR's at almost a resting heart rate?

steve Beyer

John...No swimming before RR's. Which is why I knew the HR would be up at beginning of bike in race....I just don't know: 1. why it never really calmed down. 2. why the power output was what I would consider significantly lower(for the first hour or more at least....around 200 as opposed to 220-225 range), at a HR that was more around a low Z4 effort.

Coach Patrick

It's hard to look at the bike split in a vacuum for a triathlon...so without seeing your HR files for the day (or entire file for the bike -- power/hr) its hard to see. Both Rachel and Rich are right in that the delta isn't that great as to be alarming. Your AHR for both RRs was say 144..and you raced at 152. Higher, for sure, but 8 beats is within range...that said for someone who is super steady, that 8 beats could seem like a lot!

A few things in no order:

+ If you are training for a full, or doing longer than HIM efforts, I find the HIM work is "harder" on my body...I just want to be in IM mode...not sure what plan you are on, but that's something. Just n=1.

+ We don't know what your swim pacing was or what you wore (full? Long john? Skinsuit) so hard to tell what your HR "started" at for the beginning of the bike.

+ We don't know if you took it easy in the first 15' to 25' of the bike to get your HR down per our race protocols. We say JRA on the bike but few guys actually do it.

+ The fact you popped on the run shows that you were running "hot" all things considered...and that the bike was probably too much effort.

+ Did you pee on the bike? You didn't mention fueling / hydration so again, not sure if inputs were there to support the desired outcomes.

My big takeaway from this, for me and for you, is that you have to listen to your HR -- I say this firmly as I put you in the "experienced" athlete category with multiple races and data to consider, plus your ability to be steady.

Some days you are the bug, some days you are the windshield. If on race day your goal watts just feel too hard, and are backed up by higher HR data, then dial it back a bit. In most cases this is 1% to 3% of effort...would it have been that bad to ride at 205 vs 210? My guess is you would have still been faster than last year but in an HR space that would have allowed you to run a much better run.

But of course, I don't know how you paced the run. Did you cap your HR at the start and fuel up?

Sooooooo many variables....

Coach Patrick

Any updates here Steve to my questions?