So, back in the days, a method to establish IM race goal watts would be taking 95% of your latest 20-mins test (to establish a FTP estimate) and then use 73-77% of that, as an Intensity factor to establish goal watts. So you´d do 315w in a 20-mins test, meaning your “FTP” would be 300w and therefore, your could use maybe 0.75 as IF, to calculate 0.75 x 300w = 225w as relevant goal watts.
This has (like 10 years ago, when I latest did Ironman races) worked well for me and I have had fastish/balanced Ironman races using this ancient method, and as a coach I used this 100s of times with athletes. Again … a loooong time ago
But I am curious: What are people using today to estimate goal watts for Ironman? Be it Pros, FOPs or even slower Ironman triathletes.
Lactate testing could be one maybe? That I dont really have access to.
I set a conservative ftp target for the first long race prep session, then bump it up each week while monitoring decoupling. Also helps dial in hydration.
I agree! Been using this a lot too. I wonder if, now that bikes and positions have improved so much, if the numbers in that table are still 100% reliable. I think bike splits have become 10-15 mins faster over the last 10 years for AGs, at the same watts … just a thought…
I think 73-77% is still relevant as a starting point. I see this chart referenced a lot also.
I agree! Been using this a lot too. I wonder if, now that bikes and positions have improved so much, if the numbers in that table are still 100% reliable. I think bike splits have become 10-15 mins faster over the last 10 years for AGs, at the same watts … just a thought…
I think 73-77% is still relevant as a starting point. I see this chart referenced a lot also.
Watts and IF don’t care how fast you are going…
So time is a critical input. And since distance is fixed… Speed is implied.//
Thanks for mentioning this important factor in the equation. Just like in swimming, there is a metabolic cost for each and every minute you swim longer than your competition. So it is with cycling too. In my day, a 5 hour ironman ride was the state of the art, and now that has gone down to 4 hours. There is a lot of extra eating and drinking that has to go on in that extra hour, and the metabolic cost is certainly going to show up in the run times too.
Reminds me of the hard heads that say power is power, never mind anything else when riding…
I use a mix of lactate and testing in training. During the IM prep (last 12-14 weeks) I like to start 20 watts below my LT1, and do maybe 3x40 minutes in the TT position. If that feels good and I can hit 100 grams of carbs pr hour, next longer session I bump it up 5-10 watts. With 2 sessions of TT training around IM pace a week, it gives me around 20 sessions in the build up - to hit the right intensity. I try to get 2 sessions with 4 hours of specific intensity before the race - to get a feel for going fast and hitting my nutrition.
I coach some athletes without access to lactate - but it’s almost the same thing. When they go too hard in training (they almost always do at some point in the build) we know they hit above target. Also X x 30 minutes starting conservative and then adding 10 watts every interval, you can almost feel where your limit is.
To make sure - try to swim hard in the morning, bike 5 hours including 4x50 minutes @ racepace and then run your long run the day after. How did the run feel? If it takes more than 4-5k to feel “normal,” then you went too hard on the bike the day before (or didn’t fuel enough during or after the bike).
I would say that a good way of testing if you’re in the right ballpark is 1-1.5 hour at goal pace at the end of a long ride and seeing how your body responds and if you have any HR drift.
I use a mix of lactate and testing in training. During the IM prep (last 12-14 weeks) I like to start 20 watts below my LT1, and do maybe 3x40 minutes in the TT position. If that feels good and I can hit 100 grams of carbs pr hour, next longer session I bump it up 5-10 watts. With 2 sessions of TT training around IM pace a week, it gives me around 20 sessions in the build up - to hit the right intensity. I try to get 2 sessions with 4 hours of specific intensity before the race - to get a feel for going fast and hitting my nutrition.
I coach some athletes without access to lactate - but it’s almost the same thing. When they go too hard in training (they almost always do at some point in the build) we know they hit above target. Also X x 30 minutes starting conservative and then adding 10 watts every interval, you can almost feel where your limit is.
To make sure - try to swim hard in the morning, bike 5 hours including 4x50 minutes @ racepace and then run your long run the day after. How did the run feel? If it takes more than 4-5k to feel “normal,” then you went too hard on the bike the day before (or didn’t fuel enough during or after the bike).
This is the answer. It’s not fun because it involves doing very hard training sessions (which you should be doing anyways if you’re looking at setting opportunities IM pace).
Going off FTP (especially from a ramp or 20min test) amd Training Peaks TSS (which is calculated off FTP is going to have divergent results. Someone doing 1h Zwift workouts everyday are going to absolutely explode. Their anaerobic strength will skew the FTP result upwards and they’ll set it at a pace far too high. Likewise someone who only does 4h Z2 rides and ‘doesn’t need speedwork’ will have an artificially low FTP (especially in a ramp test) and leave a lot of pace on the table.
Ultimately you can guess within a 40-50 watt range, but until you get it there and start trying long hard efforts it’s just guesswork.
I agree! Been using this a lot too. I wonder if, now that bikes and positions have improved so much, if the numbers in that table are still 100% reliable. I think bike splits have become 10-15 mins faster over the last 10 years for AGs, at the same watts … just a thought…
I’m not understanding your question, especially when you acknowledge anticipated time is a key input. If you’re 15 minutes faster, move down a row. For the same TSS target, you roughly move to the right 1 column (or increase power by 0.01 IF).
I don’t see the difference between 0.72 and 0.73 or a drop in time of ~5% necessitating a significant change in TSS target. The YMMV aspect of that chart and the uncertainty in determining what FTP to base it on is much much much bigger than the bike tech impact.
I have personally determined race day target power from RPE and power on long rides. That said, I’ve probably over-biked in all 3 of my IMs based on my run performance compared to open marathon performance (~+30 minutes vs +15 rule of thumb), despite targeting the low end of IF on that chart. A combination of race excitement + an overestimated FTP.
I’ve probably over-biked in all 3 of my IMs based on my run performance compared to open marathon performance (~+30 minutes vs +15 rule of thumb),
I know that its a theory that you can run your IM marathon at +15-20minutes compared to your open marathon time, but I don’t see many people doing it in the AG ranks. The vast majority, even those getting good results, are more like 25-30.
I’ve probably over-biked in all 3 of my IMs based on my run performance compared to open marathon performance (~+30 minutes vs +15 rule of thumb),
I know that its a theory that you can run your IM marathon at +15-20minutes compared to your open marathon time, but I don’t see many people doing it in the AG ranks. The vast majority, even those getting good results, are more like 25-30.
I think that’s because the AG ranks suck at managing bike effort during the race (myself included). After the taper, it’s way too easy to over-push for the first 75% of an IM and the difference between +40’ IM run and a +15’ IM run is a knife edge.
I’ve probably over-biked in all 3 of my IMs based on my run performance compared to open marathon performance (~+30 minutes vs +15 rule of thumb),
I know that its a theory that you can run your IM marathon at +15-20minutes compared to your open marathon time, but I don’t see many people doing it in the AG ranks. The vast majority, even those getting good results, are more like 25-30.
The rule isn’t that AG’s will be +15, the rule of thumb is that to have their fastest time they should be +15. Those AGs with good results 25-30min slower could have theoretically had a faster overall time if they did the bike 10 min slower and the run 15 min faster.
(of course this is also very dependent on training history. Someone doing 8h/w is never going to be +15 on an IM marathon. A top tier pro can be expected to be inside 15min regularly)
OK, I just don’t know anyone in AG ranks that actually does it. The pros seem able to do it, but not because they are pacing the bike better. If anything, they are doing more surges and riding harder overall. Perhaps total training volume or bike training volume are the big key factors.
I was curious about someone who won my AG at a recent IM in an outstanding time. Turns out they have been a world-class AGer, if that’s a thing, for many years. Google shows me a calendar year 1:16 half vs their IM run time of 3:07, which was the fastest run split by a lot. 1:16 probably equates to very low 2:40s open marathon time, i.e. +25ish minutes. Could they have ridden 5min slower and run 10min faster? Maybe, I don’t know, just doesn’t seem anyone actually does it.
OK, I just don’t know anyone in AG ranks that actually does it. The pros seem able to do it, but not because they are pacing the bike better. If anything, they are doing more surges and riding harder overall. Perhaps total training volume or bike training volume are the big key factors.
I was curious about someone who won my AG at a recent IM in an outstanding time. Turns out they have been a world-class AGer, if that’s a thing, for many years. Google shows me a calendar year 1:16 half vs their IM run time of 3:07, which was the fastest run split by a lot. 1:16 probably equates to very low 2:40s open marathon time, i.e. +25ish minutes. Could they have ridden 5min slower and run 10min faster? Maybe, I don’t know, just doesn’t seem anyone actually does it.
Both of these things can be true-the pros can be pacing the bike better and riding harder/surgy-er if their ability is high enough to handle it. Which is kind of borne out by their IM run times. I would imagine the biggest cause is that pro’s need to be honest about their pace as a matter of income, and AG’s have more of a tendency to overestimate their ability, which isn’t evident until the run.
Not doubting the very good AG guy, but comparing a 1:16 half to a 9h IM is at best half as good a comparison as a marathon to an IM. It’s equally possible that his endurance drops off such that his open time is closer to 2:50 which is only a 17min drop off.
It’s a really hard concept to test because you can do 2-3 IM’s in a year if you really press it, and it’s much easier to bike too hard than bike too easy.
But if you’re prepared for the last block of race specific training - you can “test” the bike maybe 3-4 times before the actual race. Yes, sometimes the truth is hard on the ego, but better failing in training than at the race. I guess if you never fail in training, you never know where the limit is. Then you taper - and think your can go from 70 grams pr hour and 240 watts in training to 110 gram pr hour and 260 watts in the race.
My best bike/run combo was in 2021. 10 days out from the race I did 2x50+2x30+2x20 minutes @ 8-10 watts higher than in the race on a flat course in the TT position with TT-helmet. The day after my long run was “good” - but not great like the week before. I knew I got the carbs before, during and after the ride = the power was just a bit too much. I ran exactly 20 minutes slower on the marathon in Almere (September), than a stand alone in April the same year. Almere was a bit hotter than the 10 degrees celcius marathon in April - which should be the 5 minutes longer than the “15 minutes rule”
