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where has all the coasting gone? I blame facebook and the desire for strava-friendly VI

Some Friday afternoon nostalgia here: in the old days, the bike split racing model rallied around Least-Cost Riding - sure, riding your watts when you needed to move forward, but also backing off - from anywhere to soft-pedalling to outright coasting - when the road turned downwards, to save and bank your watts and your beats for when you need them later in the race.    I'll put my bias out when I say I liked those old days, and from my 39 minutes of accumulated coasting / zero watts at IM Canada, I also like my coasting.  

Reading race plans and race reports though, it seems like there is emerging / now a different rallying point - "Low VI."  I've seen a few racers expressing outright embarrassment for high(er) VIs in reports, when they seem to have pretty darn good outcomes, if you measure those in getting the bike done well, and running well.      I get that low VI is a good thing when it denotes that you didn't burn a match going 530 watts for 3 mins in an ironman distance race, but I also wonder if this has been conflated with not coasting or backing off?   Are we now avoiding zeros? 

Also, I have a theory that social media apps where our numbers become our successes and failures might be pushing us to toss out unnecessary watts - I suspect that some of us like to work towards an outcome where we achieve the most presentable data and cleanest ride file from a race instead doing what might be the smartest things to get to, and past, T2.        

Another member and I have had a few PMs over the last year, and in our thread, I shared this quote from a comment on a different site:

"For those mathematically minded I would say that power increases polynomially with speed (to the power of 3) rather than exponentially. A 25% increase in speed represents a 95% increase in required power (1.25^3)."

When you model that out to situations going down a hill at 30mph, that is a lot of power for little return.  ditto 32, 35, 38, etc mph.   

So is a low VI a good thing on a typical (IMFL, IMAZ not being 'typical') IM bike course?   Are we spending unnecessary power just to keep zeros out, when we should instead be focusing on watts getting spent above our prescribed zones, and minimizing their costs?    

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  • That's a good question Dave.  Although I understand VI and the overall goal of keeping it low, I'll admit right here in the forums that I don't track it, don't even look it up after a ride (or a race), and I'm not even on Strava so I don't give a damn about what my data looks like to others since they never see it.  Pretty much, I just use the Power Meter to keep me in check on the big climbs and ride much more by feel than anything else.

  • edited November 3, 2017 11:20PM
    I agree, great topic to discuss...

    My first comment would be that if you're going to throw out courses like IMFL and IMAZ as outliers, I would say you also have to throw out courses like IMLP and IMCanada.  So there goes 40 minutes of coasting.  A course like Louisville that you just raced at would seem "typical."  What was the amount of time that you coasted there?

    My 2nd comment is that to consider only to think of your power output as an increase in your speed is looking at the puzzle too narrowly.  Sure when I'm going 30 mph and I'm putting out my IM race watts I don't expect to see much of an increase in speed.  But where that will help me is riding out a descent and maintaining that higher speed as long as I can.  That will add up rather quickly and IMO is worth more than any watts you might save by coasting.

    The last comment I have is about the way that I interpret AP vs. NP and how VI is related.  Lets say 2 athletes have different plans to attack a bike course.  Athlete 1 attacks the hills and coasts on the other side.  Athlete 2 decides that they will ride more conservative going up but continue that pace through the descent.  Both athletes average 200 watts and finish their ride at the exact same time.  They both spent the exact same amount of energy, however, their riding styles had "significantly" different costs.  Athlete 1 has a VI of 1.06 for an NP of 212.  Athlete 2 has a VI of 1.02 for an NP of 204.  So sure, Athlete 1 had 20 minutes of coasting vs. 5 minutes for Athlete 2, however, the stress on Athlete 1's system is 10 watts more over 5 hours!  That's a lot of TSS.

    So while at first glance it may seem that having that higher VI and coasting may be saving some watts/energy, when you boil it down, I think that even though you're pedaling for a longer duration of your ride, having a lower VI is more efficient and actually saves watts/energy.

    That's my $0.02.  
  • The only time I care about VI is when I am *racing* an Ironman. Shorter distances, training rides...I do what needs to be done, and certainly never thought about what my file would look like to someone else following me.

    My conclusion, after all those IMs I've done, some more successfully than others, is that pure coasting - not pedaling at all - should be reserved for the times when I actually spin out - which happens between 35-38 mph, depending on the gearing I'm using. In CDA (10) & Wisconsin, that was about 6 minutes total, at Canada (3) (Penticton), Lake Placid & Tahoe, about 10 minutes, and pretty much none @ IM AZ (5) /FL/MD. Kona is a different story entirely, as I've only been satisfied with 1/6 races there.

    Otherwise, I'm pretty much +/- 5% around my goal AP, depending on whether I'm going up, down, or on the flats. I don't have a "textbook" VI; my successful races have ranged from 1.025 to 1.06. But, when I;ve tried Punching" up short hills, say for 20-40 seconds, it has left me with too little in the tank on the run. I can;t see that the few seconds gained in such a strategy are worth the minutes I end up losing on the run. There's an old saying, that "for every minute you go anaerobic on the bike, you go three minutes slower on the run".

    I get a lot of good EN riders coming to visit me in CO; they're all faster than I am, so I end up spending a fair amount of time in their slipstream. The really good ones all have a common characteristic on the long rides we do there, which includes endless miles of false flats, and a lot of relatively shallow ups and downs, 3-6%. They seem to have ingrained an ability to micro adjust their speed to fit the terrain - instantly slowing down (while keeping a fairly steady effort) - at every slight uptick in the gradient, or increase in the wind. At that level, I don't think it's EN (or Slowtwitch) Kool-Aid; they've learned what works for them.

    I;ve had conversations about "Functional Reserve Capacity" (building a larger matchbook), but remain unconvinced that altering the basic EN guidance for overall IM race strategy - which DOES allow for up to 10% greater effort on hills lasting uo to five minutes - will produce a faster overall time. If anyone has examples of when that (meaning working harder on hills than the "EN way", and going easier on the downhills) *worked* for them, like setting a PR, getting on the podium, or a KQ, then please post it here... Pros are a different story; they have not only high-end physiologies, but also more time to train.
  • edited November 4, 2017 5:45PM
    I don't have alot of time to get too technical here but want to agree with Al's comments.  I see alot of smart people getting caught up in BBS, debating VI on different terrains, etc......BUT leaving out the other side of the equation regarding that we are going to prepare ourselves to be running a marathon at the end of the bike......

    BBS again, does not equate with Best run split on a Ironman run.  Riding a higher VI vs. a lower VI on a specific terrain doesn't necessarily equate with riding your "should" vs. your "could" bike effort followed by a strong, negative split marathon run.

    Prove your theory to me by running well on the marathon, and I will listen maybe.....otherwise, as AL comments above, "If anyone has examples of when that (meaning working harder on hills than the "EN way", and going easier on the downhills) *worked* for them, like setting a PR, getting on the podium, or a KQ, then please post it here...."

    SS
  • I am getting a bit of confort now to see that I can ride a 1.12-1.18 VI and run sub 4h marathon.. still not a perfect marathon but I am starting to think I just can ride smooth.
  • Not a technical girl here, but I have always been coached to spin up hills in my saddle vs get out of the saddle to climb.  I'm not trained to ride hard up a hill that way, so I don't.  I *think* some riders may do well putting out more power climbing, but they better darn well be fantastic runners and VERY WELL TRAINED and ADAPTED to ride that way.  

    I know when I let my ego or enthusiasm get the best of me and ride harder up hill than I'm trained for, its no bueno, especially as I am an adult onset runner, and a more efficient biker than runner generally.  


  • I don't disagree with the comments here. 
    When I first joined EN, I tried to use Rich's protocol but came to the conclusion that that approach didn't work for me. 
    Now, after JRA, I then aim at my goal watts everywhere (up hills, on the flat, etc), except when I spin out. I use 50/34 with 11/32, so when my cadence gets around 90 (I usually have a cadence in the low 80s, but I don't target a particular cadence) I am close to 50 kph, so I coast. I never worry about my VI (it's usually around 1.04), noting that lower isn't necessarily better. It's the run I worry about, and how to best set up the run by biking the way I should, not the one I could
  • I think any VI lower than 1.05 is ok.  Any VI higher than 1.09 and run will suffer (IME)- at least for 70.3 wher I have the bulk of my experience. 

    As I have tried to learn how to keep my VI low(er) I have discovered it's not how HIGH I push the power going uphills (within reason)  but how FAST the power is applied.  i.e. if a hill requires 250 watts to get up with some urgency, going from 200 to 250 watts in 1 pedal stroke affects my VI (and I think my legs) more than easing up to 250 over 20-30 seconds and then holding.  And the opposite is true over the crest of the hill, easing back down to regular watts rather than letting up on the gas immediately.  So when I am doing this correctly what tends to happen is people zoom by me at the base of a hill and I catch them at the top and keep going past as we go down the other side.  Then we repeat this again and again until I finally leave them behind for good. 

    You all probably knew this already but its something I discovered this summer. 
  • edited November 6, 2017 8:55PM
    I kind of do what Satish just articulated and have had success with it. 

    I'm also one of those weirdos that finds it a LOT easier to push IM watts or slightly higher on the descents as I simply enjoy going fast and I can watch my HR fall on descents even with steady power.  The opposite is true for me on climbs.  I find it hard to maintain the same (or 10% above normal) while climbing and can watch my HR rise and my sweat level go up.

    But with that said, let me defend @Dave Tallo in his original post.  A lot of the responses seem to assume that he meant a higher VI was achieved by hammering up the hills and then coasting on the descents.  I don't think that's what he was saying at all...   I think he was suggesting that a better approach (for him) is to ride the "EN way" by riding smart and spinning up the hills and generally riding smart and steady.  BUT, once you get up to "speed" on the downhill after cresting at the top under steady power to then "coast" instead of continuing to pedal at say 200W when you're in the meat of the descent.  And the difference in speed while coasting in a super aero position isn't all that much different than say continuing to pedal at IM watts, but the occasional ~30" rest to your legs might do wonders for how they feel come run time.  The by-product of this might be a higher VI, but a higher VI only hurts you on the run if its from spikes in power, not from zero's in the data set (but the math means that both of those cause a higher VI).

    https://www.youtube.com/watch?v=bvmibwafGXc

    https://www.youtube.com/watch?v=3Iz7ZMALaCY



  • I’m like @John Withrow in that I LOVE hammering the downhills. I have a hard time holding back on long descents and tend to really push watts. 

    If it’s determined that the ROI of peddling the downhills tapers off, what would be the protocol to determine when to coast on beefy descents?

    1) use watts as a cap? E.g. N% of your target watts for the race.  (If so what is N?)

    2) till you spin out. (Ramp up and hammer it till you can’t.)

    3) up till speed X because the ROI isn’t worth it. (If so what is X?)


  • This tool can be found in the wiki.  It is populated with my FTP.....note guidance in red at the bottom regarding when to soft pedal.

    Last week I raced the AUSTIN 70.3.  .83IF and 1.02 VI on the bike with 2,200 ft of climbing. This delivered my all time fastest HIM run at age 50 and only 7 minutes slower than my standalone 13.1 mile run.....
  • @Chris Oubre that's around 50 kph, although in a headwind, it is lower (which is based on Coach Rich's original guidance which was in mph).
  • @John Withrow - yep, that’s what I was getting at. I agree with all of the above on power going uphills - what I was talking about was downhills only. 

    (all of that goes out the window if you have a kom on a descent to defend, though! )

    Im going to play with K Willets bike speed calculator to put some data behind my OP ... later this
    week.   But my main point is when you’re going 30+ mph downhill, it takes a lot of power to increase that speed only nominally, and when you compare that to using no power but losing only a nominal amount of speed, coasting is a pretty good choice. 
  • In the guidance from the wiki I have posted above, it suggest that you soft pedal when you arrive at speeds of 28 - 33 mph and coast at 34 mph and above......given the exponential metabolic cost of trying to increase the speed over 34 mph........

    Over the course of 112 miles, in my case, there is very little time I see above 34 mph......
  • Whenever I post I'm always afraid I've missed the point, as I seem to have done here.  According to Sheldon's gear calculator at 90rpm (near spinning out for me on a TT bike lol) I will reach 32.7 mi/hr using the 170mm crank/50 tooth chainring/11 rear cog.  So yes, any faster than that and I am coasting or soft pedalling.  In fact, when faced with a rapid descent I usually don't pedal and keep my knees in against the top tube so I can steer a bit with my body.  The bike feels more stable that way.  
  • I think we are all trying to balance how to ride the bike efficiently and being able to run afterwards. The physics side of this equation is pretty clear... if you have a 'fixed' budget of work (kiloJules) that you are going to spend, the fastest way around a perfectly flat, windless course is to ride 100% steady. And the fastest way around a course with hills is to press a little harder on the hills and back off on the descents.

    This is what the EN guidance tells us to do. Personally, I think that the guidance in terms of speed is a little shaky since we all have different weights, aerodynamics and powertrain configurations. But taken in terms of powers, it is really good guidance.

    The debate started coming up in the sense of 'how much should I back off' and 'how hard should I press.' Coach P was pretty clear on this... follow the team guidance! Doing anything else is RISKY for your race. I 100% agree with this.

    But...

    Because we have some new tools to play with that were not in place when the EN guidance was written (BBS to model the course, Loading Power -based courses to your Garmin), it seems reasonable (for my own races) to experiment with how to use these tools and for us all to discuss what works / doesn't work. EN was pioneering power as a team tool... it makes sense we would pioneer the new tools.

    I will use BBS intervals in Cabo this weekend.

    Having read all the feedback about them in here, I have modified them. I have configured the intervals so that my power is capped... and so that the amount of work that I do above average power is capped. VI will probably be around 1.05 unless something else (eg, weather) comes into play. That seem consistent with the guidance here.

    For what it is worth, my Pnorm target for the race will be 185w, my max power will be 225w, but I never get above my tempo zone. I do not have much in the way of coasting programmed, but flats will be ridden about about 175w and moderate descents at around 140w. The plan is a lot like the EN 'gears,' but there is a wider range of powers being covered. I fully expect, based on my powertrain, to be coasting starting somewhere in the lower 30s. We'll see where I end up, but I would not be surprised to have 30ish minutes of nearly coasting.

    I may blow up - lol - not the first time. But I'll share what I learn. More than likely, I will fry in the sun before having a chance to up :-)
  • Rich - good summary of your current thinking and plan. Looking forward to how it plays out. Granular detailed examination of the bike file will be critical, no matter what the outcome of your run. But, as you note, there may be other factors which could booger the whole deal, mainly heat. Good luck!
  • ...

    Last week I raced the AUSTIN 70.3.  .83IF and 1.02 VI on the bike with 2,200 ft of climbing. This delivered my all time fastest HIM run at age 50 and only 7 minutes slower than my standalone 13.1 mile run.....
    STRONG work, brother!
  • @Satish Punna don’t be afraid to post.  You made a valid point with your first comment.  It’s great to hear a variety of points of view on this stuff because it may bring to light an angle that someone may not have thought of before.  I know I’ve learned quite a bit that way.  
  • @Rich Stanbaugh - FYI....  I loaded the BBS plan into my Garmin as a Garmin Power Course for IM Louisville.  What I found is that the BBS plan had me going harder up hills harder than I felt I needed.  My goal NP for the race was 195 NP.  I would be going up a hill at say 215ish and the goal BBS power target would show 230.  The opposite was on the downhill.  BBS would say something like 130 for a goal and I would maybe hold 170 and get some speed.

    After a while, the BBS number became an interesting number to see, but not my "boss".  

    @Dave Tallo - Great thread!  I heard on a podcast recently (Training Bible Podcast) that there are good reasons for a high VI and bad reasons.  The good reason was, as you mentioned, coasting down hills when you reach certain speeds.  The bad reason is burning matches from surging.  

    @Shaughn Simmons - Great race!
  • @Brian Hagan @Al Truscott Thank you.

    @Doug Johnson - thanks for posting that......agree, very healthy to debate these things, makes us stronger as a team, moves us forward in many ways.....

    SS



  • @Rich Stanbaugh - FYI....  I loaded the BBS plan into my Garmin as a Garmin Power Course for IM Louisville.  What I found is that the BBS plan had me going harder up hills harder than I felt I needed.  My goal NP for the race was 195 NP.  I would be going up a hill at say 215ish and the goal BBS power target would show 230.  The opposite was on the downhill.  BBS would say something like 130 for a goal and I would maybe hold 170 and get some speed.

    After a while, the BBS number became an interesting number to see, but not my "boss".  
    @Brian Hagan - I noticed those big spikes when riding the plan on Zwift... so I re-planned it with a target Pnorm. This let me put a hard cap on the power so that none of the BBS segments go higher than a ceiling I chose. 

    If nothing else - I will use the 208 segment beeps to remind me to hydrate :-)
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