If I’ve done a 3:07 marathon, what would I expect to run given the same level of fitness after an IM lenth bike leg? 3:37? What is the time gain?
Same with the bike if an “open” time is 4:38, what is the time after the swim in your experience?
I’ve never done and IM and would be interested in hearing your experience to guage my own “perfect race” time potential.
-SD
I do believe that there is a direct relationship between PR times at shorter running distances and longer distances.I think I once heard to double your Half marathon time and add ten minutes.Potential counts but you still have to do the work.It would depend on how patient you are on the bike.
Cullen
I’ve never done an IM either, but I’m sure it’s impossible to accurately calculate a theoretical IM time based upon your stand alone time in any one event. I know what my century ride times are but I don’t think that even has relevance to the bike portion of an IM, let alone to the swim or run. The only way to know is actually go out and do an IM.
Cerveloguy is right in saying it’s impossible to give a very accurate time estimate for the run off the bike. That being said, assuming you’re well trained for it and pace yourself accordingly (best case scenario), it’s possible to run a marathon within 10-15% of your best time.
My guess is that the better an endurance athlete you are, the more likely you are able to stay closer to your standalone times. The double your 1/2 IM time and add an hour is probably more accurate for the average endurance athlete crazy enough to be doing an IM. You’re better than the average AG triathlete, so, you should be able to double your half and add 15 minutes?
The real problem occurs if you cook yourself by going too hard. Sonni Dyer recently wrote something like: the difference between a very good IM swim and a bad one is only about 9 minutes for the AG’er. The difference between a good bike and a bad one is about 25 minutes for the AG’er. The difference between a good IM run and a bad one is 2 hours. It’s a cliff…if you get too close, slip, and fall off, it’s a pretty big fall.
Double a half IM time & add 15 minutes? If there were some weird people who’s IM pace was close to as fast as they could possibly go, i’d say you were right. But I don’t think that’s a normal case. An above average AG’er who goes 4:30 in a HIM typically goes around 10 hours in an IM, not even close to the 9:15 your formula would suggest.
Yeah, I think you’re right. It would take an elite to be able to double his half an only add 15 minutes. I guess SuperDave isn’t quite at that level.
"How much time does the BIKE add to your RUN "
I never take my bike with me on the run, I always leave it in T2, of course with my new S25 it would probably make me faster.
Sorry I didn’t mean to insinuate SD is slow by any means. I was just looking at times of people I know who are very fast - my friend won his AG at Eagelman in 4:13 and his Pr for iron distance is 10 hours.
Top pros would have a difficult time doing the double+15. Chris Legh won eagleman in 3:47 and won IM-CDA in 8:42 - that’s double plus 1:15.
My 1/2 IM to full IM falls within your 1:15 range. My 1/2’s are about 6:02 and my IM’s are about 13:25. Thats pretty darn close.
I cooked on the last 8 miles of my last IM. I had a 12:45 all wrapped up and then all went to hell in a hand basket with 8 miles to go and ended up at a 13:46. I straggered the last 8 miles. Tried to run a few times but ended up running off the road and into the ditch! But my PR is a 13:24.
don, I know you weren’t insinuating SuperDave is slow, I was simply wrong.
The reason I said elites might go 1/2 IM doubled plus 15 minutes is a couple of elites I know have done just about that. I think the larger you are, the less likely you can do this, too. A 185 guy doing a 4 hour legitimate 1/2 would have a bugger of a time doing an 8:15 IM, but, a 135 lb. elite that has a 4 hour PR 1/2 would come closer to the 8:15. But, like I said, I was wrong…that’s too tight a time-frame.
However, what’s Gordo’s fastest half and fastest full IM times? What is his time relationship between the two distances?
…and how accurate you can predict times. Just like short course racing, you can totally blow apart your run by going to hard on the bike, so I don’t believe there is any type of gauge you can measure.
With that said, I remember hearing years ago (maybe 8-9 yrs ago via Mark Allen, Dave Scott, or someone else ruling the world at the time who wrote articles for Triathlete) that the goal to know you had a good run would be to try for only a 10% difference in your run time. With this gauge, it allowed me to figure out how much I had to slow down on the bike, to get my optimal run. It pretty much worked out perfect for me, as my PR’s were all races where my run was close to being only 10% more than the standalone run for the same distance (i.e. 1:26 for standalone 10 miler 3 weeks prior to my 1:34 for a 10 miler at the end of Ironhorse).
The formula for 1/2 IM to IM is double your 1/2 IM time and add an hour. This is the best guestimate I have heard. of course the course/weather etc would matter. So if you are a 4:45 1/2 iM guy or gal, then an IM would be 10:30. I have been close with this calculation a few times.
But, there is no perfect calcuation. The faster you are, the less time you add on after you double it up. Like TDB, his 1/2 IM time is under 4:00 - double his time and add 1/2 hour and you are about right - 8:20 ish.
Like someone said above, you don’t really know until you go out and try an Ironman. I didn’t say ‘race’ an Ironman, b/c there are only about 5 people in any given Ironman that actually ‘race’. The rest are just trying to get to the finish like like the rest of us. 
Mike,
That formula has been around for a long time, and nobody has ever really confirmed it’s accurate. Nobody I remember over the past 5 years of racing IM approached that formula on their first IM :~D (it was more like add 2 hours, one for the formula, then another for the run ;~P
Craig - yeah probably right - my first 1/2 IM was 5:00 and my first IM was 11:46 - 1993 - more about the bike for me - I ran a 4:01 even with a lot of walking. Didn’t have any bike endurance though. I think the bike took me like 6:21 or something?
Hello, The simple answer is about half and hour. If you can run a 3 hour marathon and do 3:30 in an IM you’ve had a pretty good day. A few mutants can do better, and most will do much worse, mainly because they go out too fast or go too fast on the bike.
As far as the swim effecting your bike, if you were to do s swim / bike with no run I don’t think your bike time would suffer much. What slow you down, or at least should slow you down, is the knowledge that you have to bike.
So, whats the scoop are you just curious or are we going to see you on the starting line next year?
ShawnT
Back to the point…about the run.
I’d say b/w 30-45 mins over in ideal situations for a well conditioned athlete and took adequate measures on the bike…
I would agree with Smitty - and add that a minute per mile is good and as you get toward the top end it’s less. If you can run 3:00 in an open marathon, then a 3:25/3:30 should be in your sights. I had an athlete 4 years ago that run a 4:10 Boston, and a 4:30 marathon at IMFL I would say that is a very good marathon.
Shawn,
It is on my life to do list. Next year is not likely as I’m 200#s and have been training for 2005 Elite National Track Champs and Master’s Track Worlds. I would however like to start to run next fall and lose some bulk. I ran two marathons in my life, the 3:07 a couple days after my 15th birthday with no real training for it. I ran cross country in high school and thought I’d try it for “fun” The course used a 5km loop and I simply shut down for the last 5km, I didn’t eat or drink much at all, no breakfast and about 20 ounces of water the first 2:30. The last 3 miles took 37 minutes and I don’t remember much of it. In college I was a bit smarter and had a better coach, but the focus was 8k/10k and steeplechase because I simply didn’t have any speed. I quit because I hated losing, rather I hated getting lapped in a 3000M race. Anyhow, I could knock out 20 milers in 2 hours back then, I just never had the leg speed to be fast. Well that was 50 pounds ago and I know it’ll take a year or more to find the fitness to do a 3 hour marathon. I’m much to stubborn to race an IM for the participant ribbon, so I’m going to map it out 18 months in advance. If I’m not capable of going under 11 hours I think I’d prefer to pursue other goals at this stage of my life.
If the USCF schedule is clear, I might do Gross Isle again just for S&G.
-SD