Bike racing and Ironman training

Reposting this topic from a few years back but is now relevant again (and no one was able to help last time!)

I am an Ironman athlete but also love bike racing. In fact I’m more of a bike racer than triathlete nowadays… I always struggle to get the balance right on the bike as although cycling is cycling they are two very different disciplines to train for! I always find that if I do a bike session that is VO2 or above then I struggle to hit my run intervals for a few days afterwards whereas if I’m doing longer steady state sessions that are more Ironman specific I can still hit my running intervals.

Is anyone else in the same boat - I would love to hear about your experiences. Also I should add that I am now 43 so don’t recover as quickly as I used to!

55 y/o here. Been doing tri’s since mid 80s. Training (esp bike) has definitely evolved over the years. When I started, it was steel frame bikes w/ column shifters, toe clips and a 52/42 with a 6 speed cog. “Base” was the “1,000 miles in the small chainring” approach, and I mostly applied run training theory to bike training (lots of volume/endurance riding with occasional tempo or a road rally). Starting TR a few years ago, I realized bike training should be more like swim training (higher intensity/lower volume with targeted workouts). Using TR, I did a 1/2 IM swim/bike last year, on a road bike and a tough hilly course, posting a 2:35 bike split. Had to go back thru race results to 2002 to find an equivalent split (TT bars and pancake flat course in FL). So yes, threshold and VO2max training definitely worked for me, and I found throwing in 1-2 100k gravel races per month seemed to substitute well for TR workouts. I used the TT plan for the 1/2 versus a triathlon plan. That had me doing 3-4 threshold workouts/week. Maybe dialing it down just a bit (threshold in place of VO2) on the bike workouts would allow you to recover better and nail your runs?

Not in the same boat but think that next year I might be.
Made a bit of a switch to doing some bike racing this year but think there’ll be an IM on the cards in 2023 or 2024 and so interested to see what responses you get as to how best to balance training for two distinct disciplines.

I did an Ironman earlier this year and consider myself much more of a cyclist than triathlete. One of the trickiest parts of multi-sport training is getting the pattern of high-intensity correct across the three disciplines. Over time, the high-intensity everywhere adds up to overwhelm you unless you are really keeping your eye on it.

Then, the harsh truth is that you can be very good at both bike and multi-sport racing, but you won’t be your absolute best at both without focusing totally on one or the other.


This true, more so for IM and bike, because they have different requirements, from the three energy systems, ATP-PC, Anaerobic Latate (Glycolytic) system and Aerobic (Oxidative) system, so a compromise has to be made.

Sprint Tri and crit or short road races is a better fit than IM as they have similar requirements from the energy systems, whereas IM its pretty much about maximising the Aerobic (Oxidative) system withlittle regard for the ATP and Anaerobic system, which is not the same as not training them. Keeping it simple, with this statement. :wink: and not going further into the weeds.

In theroy, IMO you want to balance reducing VLamax and increasing your VO2max and fractional utilisation, you can’t maximise both.

Trail and error to maximise performance??? Probably.

Re Recovering from VO2 work, thats difficult and requires careful planning of sessions to get the required recovery.